This study was supported by Cuiying Plan Project of Lanzhou University Second Hospital (Grant No. PR0121015) and Gansu Provincial Key Laboratory of Urinary System Disease Research (Grant No. 0412D2).

This study adhered to the guidelines outlined in the 8th edition of the Guide for the Care and Use of Laboratory Animals13. The research received approval from the Ethics Committee of Lanzhou University Second Hospital and was documented in adherence to The ARRIVE guidelines 2.014. Twelve healthy Wistar rats (six males weighing 290-330 g and six females weighing 250-280 g) aged 12-16 weeks were accommodated in the GLP Animal Laboratory of Lanzhou University for 3 days before the actual experiment. The rat cages utilized were of the R5 type, measuring 545 mm x 395 mm x 200 mm, and were equipped with autoclaved bedding material. All rats were provided unrestricted access to both food and water. The laboratory maintained an average humidity of 25%, an average temperature of 24 &#176;C, and a light cycle that alternated between day and night (7:00 AM/7:00 PM). At the conclusion of the study, all animals were humanely euthanized using an overdose of isoflurane. For comprehensive information regarding the materials and instruments employed in this study, please refer to the Table of Materials.
1. Sample size calculation and animal selection
<ol>
	<li>Choose the resource equation method15 to estimate the animal sample size using equation (1). 
	E = Total number of animals &#8722; Total number of groups&#160;&#160;(1) 
	Where E is the degree of freedom of analysis of variance (ANOVA) and ranges from 10 to 20. 
	NOTE: In this study, 12 animals were divided into two groups A and B (three males and three females per group).</li>
	<li>Define the primary outcome of this study as the success rate and time consumption of repeated blood sampling by a single individual.</li>
	<li>Define the secondary outcome measures as changes in rat body weight, food and water intake, as well as the incidence of adverse events (such as clavicle fractures, subcutaneous hematomas, pneumothorax, and mortality).</li>
	<li>Define successful blood sampling as meeting the following criteria: i) fewer than three punctures for a single blood collection; ii) a total time (from rat restraint to completion of blood collection) not exceeding 5 min; and iii) achieving the targeted blood volume while obtaining clear plasma. Consider any deviation from these criteria a sampling failure.</li>
</ol>
2. Animal restraint and blood collection
NOTE: Blood samples from group A and B rats were collected by two experienced researchers, both of whom had drawn at least 100 blood samples. Blood samples were gathered from both groups of rats for a total of 96 times over the course of 4 days. This blood collection method does not require anesthesia or additional restraint devices for the rats. However, it necessitates adept handling techniques.
<ol>
	<li>At 8:00 AM on the day before blood sampling (day 1), assign each rat to its individual cage while its food and water are weighed. Then, have another researcher, blinded to the measurements, record the rats&#39; weight, food consumption, and water intake every day at 8:00 AM from day 1 onwards.</li>
	<li>To follow this protocol, first draw blood at 10:00 AM and then at 10:00 PM each day, collecting 0.15 mL of blood alternately from the subclavian veins on both sides. 
	NOTE: The amount of blood to be collected was determined by the maximum volume that the lowest-weight rat could tolerate within a week.</li>
	<li>Flush a syringe with sodium heparin (25 U/mL) and disinfect the injection site with alcohol.</li>
	<li>Gently stroke the rat&#39;s back skin and pinch its neck repeatedly to help the rat relax (Video 1).</li>
	<li>Using the non-dominant hand&#39;s thumb and index finger, grip and lift the rat&#39;s neck skin firmly (Figure 1A and Video 1).</li>
	<li>With coordination from the dominant hand, use the remaining three fingers and palm of the non-dominant hand to secure the rat&#39;s back skin and immobilize its front limbs (Figure 1B,C and Video 2). 
	NOTE: If the rat resists or struggles, this procedure can be repeated several times to help the rat become accustomed to the handling. The following steps are key to successful blood collection.</li>
	<li>Using the non-dominant hand&#39;s index finger, gently push down on the rat&#39;s head skin while the other fingers, along with the palm, assist in outwardly rotating the shoulder joint. During this process, use the dominant hand to fully extend the rat&#39;s shoulder joint (Figure 1D-F and Video 2).</li>
	<li>Grip the rat firmly with the non-dominant hand to align the rat&#39;s head and body in a straight line (Figure 1G,H). Then, use the dominant hand to locate the position of the clavicle and confirm the puncture site (Figure 1I, Video 2, and Video 3). 
	NOTE: Shaving the rat is not necessary. In Figure 1, shaving was done only to show the clavicle and puncture position to a greater extent. When restraining rats, especially rats &#62;350 g, allowing the rat to rest its feet on a solid surface will help support their body weight. Additionally, the restrainer should monitor the respiratory rate of each rat while collecting blood to ensure the restraint is not too tight, which may cause respiratory distress.</li>
	<li>Holding the syringe parallel to the rat&#39;s body in the dominant hand, with the needle tip facing upwards and the syringe scale toward the experimenter, maintain an approximately 15&#176; angle with the midline of the rat&#39;s body. Insert the needle 0.5 cm below the clavicle notch (at the junction of the proximal third of the clavicle and the sternum), ensuring that the needle remains parallel to the rat&#39;s body (Figure 1J and Video 3). 
	NOTE: Particular attention should be paid to the angle and depth of the needle insertion to avoid piercing the blood vessel or causing inadvertent damage to adjacent vessels.</li>
	<li>Gently withdraw the syringe slightly to create a negative pressure, often accompanied by a palpable sensation of breakthrough upon entering the blood vessel (particularly pronounced during the initial blood collection). Maintain this position and collect 0.1-1.0 mL of blood at a constant speed as needed (following the IACUC guidelines of approximately 4-5.3 mL/kg of blood per week1) (Figure 1K and Video 3).</li>
	<li>If there is no blood upon puncture, try gently adjusting the angle and depth of the needle or gently rotate the syringe (Video 3). If three consecutive attempts on the same side are unsuccessful, stop all bleeding and then switch to the opposite side for the puncture. 
	&#8203;NOTE: Swift puncture through the skin is advisable to prevent the rat from struggling due to discomfort.</li>
	<li>Apply a cotton swab for hemostasis and return the rat to its cage (Video 4).</li>
	<li>Process the blood samples according to the experimental requirements.</li>
</ol>
3. Blood sample processing
<ol>
	<li>Dispose of the syringe needle into a sharps container. Transfer the collected blood into a 1.5 mL microcentrifuge tube previously rinsed with heparin. Place the tube into a centrifuge, setting it at 4 &#176;C and 1,200 x g, and centrifuge for 10 min to separate plasma. Transfer the serum using a 1.0 mL Pasteur pipette into a clean microcentrifuge tube and store it at -80 &#176;C. 
	&#8203;NOTE: To prevent hemolysis due to pressure, remove the needle tip when necessary. During plasma aspiration, avoid drawing blood cells from the bottom of the tube. Occasionally, the surface of the syringe might collect rat fur; take care not to allow any fur to enter the tube, as it can lead to clotting.</li>
</ol>
4. Statistical analysis
<ol>
	<li>Present all data as mean &#177; standard deviation and test them for homogeneity of variance.</li>
	<li>Use Fisher&#39;s exact test to compare the success rates between groups.</li>
	<li>Use a two-sample independent t-test to compare the overall means between the two groups.</li>
	<li>Use analysis of variance (ANOVA) for continuous measurements such as blood sampling time, body weight, food intake, and water consumption. Consider P &#60; 0.05 statistically significant.</li>
</ol>

Subclavian Vein Puncture Method for Repeated Blood Collection in Conscious Rats

<ol>
	<li>. Blood collection: The rat IACUC Guideline Available from: <a target="_blank" href="https://iacuc.ucsf.edu/sites/g/files/tkssra751/f/wysiwyg/GUIDELINE%20-%20Blood%20Collection%20-%20Rat.pdf">https://iacuc.ucsf.edu/sites/g/files/tkssra751/f/wysiwyg/GUIDELINE%20-%20Blood%20Collection%20-%20Rat.pdf</a> (2022)</li><li>Hattori, N., Takumi, A., Saito, K., Saito, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+serial+cervical+or+tail+blood+sampling+on+toxicity+and+toxicokinetic+evaluation+in+rats.">Effects of serial cervical or tail blood sampling on toxicity and toxicokinetic evaluation in rats.</a> The Journal of Toxicological Sciences. 45 (10), 599-609 (2020).</li><li>Liu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modified+blood+collection+from+tail+veins+of+non-anesthetized+mice+with+a+vacuum+blood+collection+system+and+eyeglass+magnifier.">Modified blood collection from tail veins of non-anesthetized mice with a vacuum blood collection system and eyeglass magnifier.</a> Journal of Visualized Experiments. (144), e65513 (2019).</li><li>Zou, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Repeated+blood+collection+from+tail+vein+of+non-anesthetized+rats+with+a+vacuum+blood+collection+system.">Repeated blood collection from tail vein of non-anesthetized rats with a vacuum blood collection system.</a> Journal of Visualized Experiments. (130), e55852 (2017).</li><li>Charl&#232;s, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modified+tail+vein+and+penile+vein+puncture+for+blood+sampling+in+the+rat+model.">Modified tail vein and penile vein puncture for blood sampling in the rat model.</a> Journal of Visualized Experiments. (196), e65513 (2023).</li><li>Wang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Repetitive+blood+sampling+from+the+subclavian+vein+of+conscious+rat.">Repetitive blood sampling from the subclavian vein of conscious rat.</a> Journal of Visualized Experiments. (180), e63439 (2022).</li><li>Yang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subclavian+vein+puncture+as+an+alternative+method+of+blood+sample+collection+in+rats.">Subclavian vein puncture as an alternative method of blood sample collection in rats.</a> Journal of Visualized Experiments. (141), e58499 (2018).</li><li>Tochitani, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+microsampling+on+toxicity+assessment+of+hematotoxic+compounds+in+a+general+toxicity+study+in+rats.">Effects of microsampling on toxicity assessment of hematotoxic compounds in a general toxicity study in rats.</a> The Journal of Toxicological Sciences. 47 (7), 269-276 (2022).</li><li>Harikrishnan, V. S., Hansen, A. K., Abelson, K. S., S&#248;rensen, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+various+methods+of+blood+sampling+in+mice+and+rats:+Effects+on+animal+welfare.">A comparison of various methods of blood sampling in mice and rats: Effects on animal welfare.</a> Laboratory Animals. 52 (3), 253-264 (2018).</li><li>Yokoyama, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lack+of+toxicological+influences+by+microsampling+(50+&#181;L)+from+jugular+vein+of+rats+in+a+collaborative+28-day+study.">Lack of toxicological influences by microsampling (50 &#181;L) from jugular vein of rats in a collaborative 28-day study.</a> The Journal of Toxicological Sciences. 45 (6), 319-325 (2020).</li><li>Korfmacher, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utility+of+capillary+microsampling+for+rat+pharmacokinetic+studies:+Comparison+of+tail-vein+bleed+to+jugular+vein+cannula+sampling.">Utility of capillary microsampling for rat pharmacokinetic studies: Comparison of tail-vein bleed to jugular vein cannula sampling.</a> Journal of Pharmacological and Toxicological Methods. 76, 7-14 (2015).</li><li>Lu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microsurgical+skills+of+establishing+permanent+jugular+vein+cannulation+in+rats+for+serial+blood+sampling+of+orally+administered+drug.">Microsurgical skills of establishing permanent jugular vein cannulation in rats for serial blood sampling of orally administered drug.</a> Journal of Visualized Experiments. (178), e63167 (2021).</li><li>National Research Council of the National Academies, Committee for the Update of the Guide for the Care and Use of Laboratory Animals. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Guide for the Care and Use of Laboratory Animals. , (2011).</li><li>Perciedu Sert, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ARRIVE+guidelines+2.0:+updated+guidelines+for+reporting+animal+research.">The ARRIVE guidelines 2.0: updated guidelines for reporting animal research.</a> The Journal of Physiology. 598 (18), 3793-3801 (2020).</li><li>Charan, J., Kantharia, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+calculate+sample+size+in+animal+studies.">How to calculate sample size in animal studies.</a> Journal of Pharmacology &amp; Pharmacotherapeutics. 4 (4), 303-306 (2013).</li><li>Turner, P. V., Pang, D. S., Lofgren, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+pain+assessment+methods+in+laboratory+rodents.">A review of pain assessment methods in laboratory rodents.</a> Comparative Medicine. 69 (6), 451-467 (2019).</li><li>Kurata, M., Misawa, K., Noguchi, N., Kasuga, Y., Matsumoto, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+blood+collection+imitating+toxicokinetic+study+on+rat+hematological+parameters.">Effect of blood collection imitating toxicokinetic study on rat hematological parameters.</a> The Journal of Toxicological Sciences. 22 (3), 231-238 (1997).</li><li>Zeller, W., Weber, H., Panoussis, B., B&#252;rge, T., Bergmann, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refinement+of+blood+sampling+from+the+sublingual+vein+of+rats.">Refinement of blood sampling from the sublingual vein of rats.</a> Laboratory Animals. 32 (4), 369-376 (1998).</li></ol>

The authors have no relevant financial or non-financial interests to disclose.

Although tail vein blood collection is the most common method for repeated blood sampling in rats, it might be influenced by anesthesia drugs, and due to the small size of the tail vein, the amount of blood that can be collected in a single instance is limited, leading to a longer blood collection duration4,5. Although high-performance liquid chromatography (HPLC) -tandem mass spectrometry (MS/MS) systems combined with capillary microsampling (CMS) of rat tail ve...

<a href="https://app.jove.com/t/6595">This corrects</a> the article <a href="https://dx.doi.org/10.3791/66075">10.3791/66075</a>

An erratum was issued for: <a href="https://www.jove.com/t/66075">Subclavian Vein Blood Sampling in Conscious Rats</a>. The Discussion section was&#160;updated.

Erratum: Subclavian Vein Blood Sampling in Conscious Rats

Rats are one of the most common experimental animals, and there are many ways to obtain blood samples. For experiments involving a single blood collection at the concluding stage, a sufficient amount of blood can be obtained through cardiac puncture or abdominal aorta blood collection1. However, some studies require repeated blood collection from rats for routine blood or biochemical analysis, especially in pharmacokinetics and toxicology studies, where repeated blood collection is required to determine the absorption, distribution, and metabolism of drugs2.
Currently, although tail vein blood collection is the most common method for blood sampling from rats, despite not requiring anesthesia, this method can be challenging for repeated collections, and the volume of blood collected is relatively small3,4. Additionally, although blood can be collected from the saphenous and penile veins, the amount of blood obtained is limited, and anesthesia is required1,5. Furthermore, blood samples collected from the submandibular venous plexus, as well as sublingual, jugular, and subclavian veins provide higher-quality samples but typically require anesthesia or the assistance of multiple individuals1,6,7,8,9. Finally, retro-orbital sinus/canal blood collection not only necessitates anesthesia but may also potentially cause injury and stress to the rats9.
The quality of blood samples typically obtained from major veins is generally of the highest standard1. At present, some studies have found that continuous microsampling through the jugular vein is a very suitable method for toxicological research in rats although this method usually requires jugular vein catheterization10,11,12. Therefore, it is worth exploring how to obtain high-quality blood samples in accordance with the 3R principle of animal research without surgical intervention. The objective of this study was to present a method for efficiently extracting blood from the subclavian vein in rats. This technique enables the swift collection of satisfactory samples through a single-person procedure without the need for anesthesia.

<table><tbody><tr><td>0.75% normal saline</td><td>Gansu Fuzheng Pharmaceutical Technology Co., Ltd.</td><td>&amp;mdash;&amp;mdash;</td><td>Prepared heparin sodium solution</td></tr><tr><td>1 mL Pasteur pipette&amp;nbsp;</td><td>Biosharp</td><td>BS-XG-01-NS</td><td>Blood collection</td></tr><tr><td>1 mL syringe (26 G, 0.45 mm x 12 mm)</td><td>Shinva Medical Instrument Co.,Ltd.</td><td>0.45*12RWLB</td><td>Blood collection&amp;nbsp;</td></tr><tr><td>1.5 mL Eppendorf tube</td><td>Biosharp</td><td>BS-15-M</td><td>Blood storage and collection</td></tr><tr><td>75% medical alcohol</td><td>Shandong Lircon Medical Technology Co., Ltd.</td><td>&amp;mdash;&amp;mdash;</td><td>Disinfection of rat blood collection site</td></tr><tr><td>Centrifuge tube holder</td><td>Biosharp</td><td>BS-05/15-SM60</td><td>&amp;mdash;&amp;mdash;</td></tr><tr><td>Electronic scale</td><td>Shanghai PUCHUN Measure Instrument Co., Ltd.</td><td>JE1002</td><td>Weigh</td></tr><tr><td>Heparin sodium injection</td><td>Hebei Changshan Biochemical Pharmaceutical Co., Ltd.</td><td>&amp;mdash;&amp;mdash;</td><td>Rinse the syringe and EP tube; dilute with normal saline to 25 U/mL</td></tr><tr><td>Low temperature centrifuge</td><td>HuNan Xiang Yi Centrifuge Instrument&amp;nbsp; Co., Ltd.</td><td>&amp;nbsp;H1750R</td><td>Separation of serum</td></tr></tbody></table>

subclavian vein blood sampling in conscious rats

There are several established methods for obtaining repeated blood samples from rats, with the most commonly employed methods being lateral tail vein sampling without anesthesia and jugular vein sampling with anesthesia. However, most of these methods require assistance and anesthetic equipment and sometimes pose difficulties in terms of blood collection or the poor quality of blood samples. In addition, these methods of blood collection consume significant time and human resources when repeated blood sampling is required for a large number of rats. This study presents a technique for repetitive blood sampling in non-anesthetized rats by a single proficient individual. Highly satisfactory blood samples can be obtained by puncturing the subclavian vein. The method demonstrated an impressive overall success rate of 95%, with a median time of merely 2 min from rat restraint to the completion of blood collection. Furthermore, performing consecutive blood collections within the designated range does not inflict any harm on the rats. This method is worth promoting for blood collection, especially in large-scale pharmacokinetic studies.

High-quality plasma specimens exhibit a pale-yellow hue, clarity, and transparency, devoid of any red tinge or clotting, as depicted in Figure 2A. Figure 2B shows hemolysis (left side) or coagulation (right side) as a result of improper procedures, respectively. Over the course of 96 blood collection sessions within 4 days, the average single blood collection times for groups A and B were 119.87 &#177; 33.62 s and 123.28 &#177; ...

Watch this Scientific Journal Video about Developing an Efficient Blood Collection Method in Non-Anesthetized Rats at JoVE.com

Author Spotlight: Developing an Efficient Blood Collection Method in Non-Anesthetized Rats 

Here we present a combination of effective rat restriction and subclavian vein puncture methods that enable rapid, safe, and repeated blood collection in rats without anesthesia.

Subclavian Vein Blood Sampling in Conscious Rats

There are several established methods for obtaining repeated blood samples from rats, with the most commonly employed methods being lateral tail vein ...

subclavian-vein-blood-sampling-in-conscious-rats

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1.7K Views.  Lanzhou University Second Hospital. Here we present a combination of effective rat restriction and subclavian vein puncture methods that enable rapid, safe, and repeated blood collection in rats without anesthesia.

Video: Author Spotlight: Developing an Efficient Blood Collection Method in Non-Anesthetized Rats 

Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements

In multiple fields of study, access to the circulatory system in laboratory studies is necessary. Pharmacological studies in rats using chronically implanted catheters permit a researcher to effectively and humanely administer substances, perform repeated blood sampling and assists in conscious direct measurements of blood pressure and heart rate. Once the catheter is implanted long-term sampling is possible. Patency and catheter life depends on multiple factors including the lock solution used, flushing regimen and catheter material. This video will demonstrate the methodology of femoral artery and venous catheterization of the rat. In addition the video will demonstrate the use of the femoral venous and arterial catheters for blood sampling, drug administration and use of the arterial catheter in taking measurements of blood pressure and heart rate in a conscious freely-moving rat. A tether and harness attached to a swivel system will allow the animal to be housed and have samples taken by the researcher with minimal disruption to the animal. To maintain patency of the catheter, careful daily maintenance of the catheter is required using lock solution (100 U/ml heparinized saline), machine-ground blunt tip syringe needles and the use of syringe filters to minimize potential contamination. With careful aseptic surgical techniques, proper catheter materials and careful catheter maintenance techniques, it is possible to sustain patent catheters and healthy animals for long periods of time (several weeks).

Chronic catheterization of blood vessels in the rat is often required for administration of substances, obtain blood sample over a period of time or for direct conscious blood pressure measurements. Femoral arterial catheterization of the rat and corresponding measurements of blood pressure in the conscious animal will be demonstrated.

In multiple fields of study, access to the circulatory system in laboratory studies is necessary. Pharmacological studies in rats using chronically ...

Training a Sophisticated Microsurgical Technique: Interposition of External Jugular Vein Graft in the Common Carotid Artery in Rats

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in peripheral arterial bypass surgery as well as in arteriovenous fistulas.1-5 The experimental procedure of vein graft interposition in the common carotid artery by using the cuff-technique has been applied in several research projects to examine the aetiology of neointimal hyperplasia and therapeutic options to address it. 6-8 The cuff prevents vessel anastomotic remodeling and induces turbulence within the graft and thereby the development of neointimal hyperplasia.
Using the superior caval vein graft is an established small-animal model for venous arterialization experiment.9-11 This current protocol refers to an established jugular vein graft interposition technique first described by Zou et al., 9 as well as others.12-14 Nevertheless, these cited small animal protocols are complicated.
To simplify the procedure and to minimize the number of experimental animals needed, a detailed operation protocol by video training is presented. This video should help the novice surgeon to learn both the cuff-technique and the vein graft interposition. Hereby, the right external jugular vein was grafted in cuff-technique in the common carotid artery of 21 female Sprague Dawley rats categorized in three equal groups that were sacrificed on day 21, 42 and 84, respectively. Notably, no donor animals were needed, because auto-transplantations were performed. The survival rate was 100 % at the time point of sacrifice. In addition, the graft patency rate was 60 % for the first 10 operated animals and 82 % for the remaining 11 animals. The blood flow at the time of sacrifice was 8&plusmn;3 ml/min. In conclusion, this surgical protocol considerably simplifies, optimizes and standardizes this complicated procedure. It gives novice surgeons easy, step-by-step instruction, explaining possible pitfalls, thereby helping them to gain expertise fast and avoid useless sacrifice of experimental animals.

Neointimal hyperplasia is the primary cause of stenosis in arterialized veins. We propose a new protocol whereby the right external jugular vein is grafted using the cuff technique in the common carotid artery of Sprague Dawley rats. The survival rate was 100 % at the time point of sacrifice.

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in ...

Repeated Blood Collection from Tail Vein of Non-Anesthetized Rats with a Vacuum Blood Collection System

Blood can be collected from rats in a number of sampling locations. For instance, the tail vein is a superior location for blood sampling. However, the tail vein is thin so that it is sometimes hard to puncture. In addition, the tail vein has low blood flow and requires a long sampling time to get sufficient blood. The present report describes a simple blood sampling method, the vacuum blood collection method, which is usually used to obtain blood samples from patients, here used for non-anesthetized rats. The 22 G butterfly needle tip was inserted into one of the lateral tail veins approximately 2-3 cm from the tip of the tail at an angle of approximately 20&#176;, and blood was collected in the vacuum collection tube by inserting the rubber end of the butterfly needle into the vacuum blood collection tube. The present experimental results show that the success rate was 95% in the experimental group and 90% in the beginner group. The success rate and puncture times were similar between two groups. The sampling duration was significantly shorter in the experimental group compared to beginner group. In conclusion, this vacuum blood collection method for sequential blood sampling from the tail vein of non- anesthetized rats is feasible and easy-to-learn, which might serve as a reliable alternative to other conventionally used blood sampling techniques for rats.

Here, we describe a simple tail vein blood sampling method in non-anesthetized rats using a vacuum extraction tube system. This method reduces the risk of direct exposure to blood and simplifies taking multiple samples from a single venipuncture.

Blood can be collected from rats in a number of sampling locations. For instance, the tail vein is a superior location for blood sampling. However, the ...

Subclavian Vein Puncture As an Alternative Method of Blood Sample Collection in Rats

Blood collection with enough blood volume is essential in animal experiments. Blood collection from the tail vein of rats is popular and less stressful compared to other more aggressive methods such as retro-orbital plexus sample collection. However, this blood collection method is sometimes limited by an unsatisfactory success rate. Here, we introduce a method for blood collection through the subclavian vein puncture. The subclavian vein is located just under the clavicle and this vein is large enough to fulfill the volume requirements of blood collection. Our results show that this method is safe and applicable for blood collection sampling with the required blood volume. Blood collection through the subclavian vein puncture could serve as an alternative blood collection method in case of failed tail vein blood sampling in rats.

Here, we present a protocol to collect blood samples from the rat subclavian vein.

Blood collection with enough blood volume is essential in animal experiments. Blood collection from the tail vein of rats is popular and less stressful ...

Blood Collection Through Subclavian Vein Puncture in Mice

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in research work. Tail blood collection is a popular method when a small amount of blood sample is needed. Orbital artery could be considered if a large amount of blood is needed but this blood collection method has ethical issues. Formerly, we demonstrated the feasibility and safety of blood sample collection through subclavian vein puncture in rats, and here we investigate whether this method could be used in mice. We report that this method is safe and practical for blood collection in mice. Blood collection through the subclavian vein puncture in mice can be a convenient method in daily research works.

Here, we present a protocol to take blood samples from the subclavian vein of mice.

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in ...

Sampling Blood from the Lateral Tail Vein of the Rat

Blood samples are commonly obtained in many experimental contexts to measure targets of interest, including hormones, immune factors, growth factors, proteins, and glucose, yet the composition of the blood is dynamically regulated and easily perturbed. One factor that can change the blood composition is the stress response triggered by the sampling procedure, which can contribute to variability in the measures of interest. Here we describe a procedure for blood sampling from the lateral tail vein in the rat. This procedure offers significant advantages over other more commonly used techniques. It permits rapid sampling with minimal pain or invasiveness, without anesthesia or analgesia. Additionally, it can be used to obtain large volume samples (upwards of 1 ml in some rats), and it may be used repeatedly across experimental days. By minimizing the stress response and pain resulting from blood sampling, measures can more accurately reflect the true basal state of the animal, with minimal influence from the sampling procedure itself.

Blood samples are useful for assessing biomarkers of physiological states or disease in vivo. Here we describe the methodology to sample blood from the lateral tail vein in the rat. This method provides rapid samples with minimal pain and invasiveness.

Blood samples are commonly obtained in many experimental contexts to measure targets of interest, including hormones, immune factors, growth factors, ...

Biology

Microsurgical Skills of Establishing Permanent Jugular Vein Cannulation in Rats for Serial Blood Sampling of Orally Administered Drug

Blood sampling in small laboratory animals is necessary for pharmaceutical lead optimization but can cause great harm and stress to experimental animals, which could potentially affect results. The jugular vein cannulation (JVC) in rats is a widely used model for repeated blood collection but requires adequate training of surgery skills and animal care. This article details the microsurgical procedures for establishing and maintaining a permanent JVC rat model with specific focus on the placement and sealing of the jugular cannula. The importance of monitoring physiological (e.g., body weight, food, and water intake) and hematological parameters, was highlighted with results presented for 6 days post-surgery during the rat&#39;s recovery. The drug-plasma concentration-time profile of orally administered natural phenol ellagic acid was determined in the JVC rat model.

Detailed microsurgical techniques are demonstrated to establish a longer-term jugular vein cannulation rat model for sequential blood collection in the same animal. Physiological and hematological parameters have been monitored during the rat's recovery phase. This model has been applied to study pharmacokinetics of orally administered polyphenol without inducing animal stress.

Blood sampling in small laboratory animals is necessary for pharmaceutical lead optimization but can cause great harm and stress to experimental animals, ...

Cerebrospinal Fluid and Blood Withdrawal from Rats with Concurrent EEG Recording

Sampling Cerebrospinal Fluid and Blood from Lateral Tail Vein in Rats During EEG Recordings

Because the composition of body fluids reflects many physiological and pathological dynamics, biological liquid samples are commonly obtained in many experimental contexts to measure molecules of interest, such as hormones, growth factors, proteins, or small non-coding RNAs. A specific example is the sampling of biological liquids in the research of biomarkers for epilepsy. In these studies, it is desirable to compare the levels of molecules in cerebrospinal fluid (CSF) and in plasma, by withdrawing CSF and plasma in parallel and considering the time distance of the sampling from and to seizures. The combined CSF and plasma sampling, coupled with video-EEG monitoring in epileptic animals, is a promising approach for the validation of putative diagnostic and prognostic biomarkers. Here, a procedure of combined CSF withdrawal from cisterna magna and blood sampling from the lateral tail vein in epileptic rats that are continuously video-EEG monitored is described. This procedure offers significant advantages over other commonly used techniques. It permits rapid sampling with minimal pain or invasiveness, and reduced time of anesthesia. Additionally, it can be used to obtain CSF and plasma samples in both tethered and telemetry EEG recorded rats, and it may be used repeatedly across multiple days of experiment. By minimizing the stress due to sampling by shortening isoflurane anesthesia, measures are expected to reflect more accurately the true levels of investigated molecules in biofluids. Depending on the availability of an appropriate analytical assay, this technique may be used to measure the levels of multiple, different molecules while performing EEG recording at the same time.

Author Spotlight: Obtaining High-Quality CSF and Blood Samples for Epilepsy Biomarker Discovery 

The protocol shows repeated cerebrospinal fluid and blood collections from epileptic rats performed in parallel with continuous video-electroencephalogram (EEG) monitoring. These are instrumental for exploring possible links between changes in various body fluid molecules and seizure activity.

Because the composition of body fluids reflects many physiological and pathological dynamics, biological liquid samples are commonly obtained in many ...

Neuroscience

Repetitive Blood Sampling from the Subclavian Vein of Conscious Rat

Rats are widely used in pharmacokinetics (PK) and toxicokinetic (TK) studies that need to collect a certain amount of blood at specific time points to detect drug exposure. The rat blood sampling method determines the quality of the plasma and further affects the precision of the test results. The subclavian vein blood collection method described in this protocol collects blood samples repeatedly in the conscious state of animals to meet the needs of PK and TK tests. The skills of restraint handling and appropriate procedure of needle incision ensure the success rate of blood collection. It is easy to operate while ensuring the quality of plasma and at the same time catering to animal welfare. However, this method requires skilled operation, and an improper one may cause animal weakness, pain, lameness, and even mortality. The current method has been used in the testing facility for a 4-week oral toxicity study in Sprague Dawley (SD) rats with TK. The maximum amount of blood collected within 24 h did not exceed 20% of the animal's total blood. The animals' body weight was more than 200 g for males and females. The data showed that the animals' bodyweight increased steadily every week, and the clinical observation was normal after repetitive sample collection.

The present protocol describes a simple and efficient method for collecting blood from the subclavian vein in rats. It enables rapid, timely, and easily identifiable sampling without anesthesia and obtains high-quality blood through repetitive sample collection.

Rats are widely used in pharmacokinetics (PK) and toxicokinetic (TK) studies that need to collect a certain amount of blood at specific time points to ...

Comparative Study of Blood Collection Techniques in Rats

Modified Tail Vein and Penile Vein Puncture for Blood Sampling in the Rat Model

Blood samples are required in most experimental animal designs to assess various hematological parameters. This paper presents two procedures for blood collection in rats: the lateral tail vein puncture and the dorsal penile vein puncture, which offer significant advantages over other previously described techniques. This study shows that these two procedures allow for fast sampling (under 10 min) and yield sufficient blood volumes for most assays (202 &#956;L &#177; 67.7 &#956;L). The dorsal penile vein puncture must be done under anesthesia, whereas the lateral tail vein puncture can be done on a conscious, restrained animal.
Alternating these two techniques, therefore, enables blood draw in any situation. While it is always recommended for an operator to be assisted during a procedure to ensure animal welfare, these techniques require only a single operator, unlike most blood sampling methods that require two. Moreover, whereas these previously described methods (e.g., jugular stick, subclavian vein blood draw) require extensive prior training to avoid harm to or death of the animal, tail vein and dorsal penile vein puncture are rarely fatal. For all these reasons, and according to the context (e.g., for studies including male rats, during the perioperative or immediate postoperative period, for animals with thin tail veins), both techniques can be used alternately to enable repeated blood draws.

Author Spotlight: Context Dependent Blood Collection Methods in Rats 

Here, we present a protocol to offer rapid, easy, and reliable blood collection alternatives for the rat model. We describe three different blood sampling methods according to the context: tail vein puncture under anesthesia or on a conscious animal, and dorsal penile vein puncture under anesthesia.

Blood samples are required in most experimental animal designs to assess various hematological parameters. This paper presents two procedures for blood ...