This work was supported by the National Nature Science Foundation of China (81570399 and 81773735), the National Key Research and Development Program of China - Traditional Chinese Medicine Modernization Research project (2017YFC1702003), and Hei Long Jiang Outstanding Youth Science Fund (JC2017020).

All procedures involving animals and their care were approved by the Institutional Animal Care and Use Committee of Harbin Medical University.
NOTE: The tools and equipment required for the method are listed in the Table of Materials.
1. Preparation of materials and animals
<ol>
	<li>Order C57BL/6 male mice with weight between 20 g-25 g from a standard laboratory animal supplier.</li>
	<li>House the mice in a cycle of 12 h light: 12 h darkness at 24&#8722;26 &#176;C with ad libitum access to water and food.</li>
</ol>
2. Parabiosis
<ol>
	<li>Anesthetize the mice by intraperitoneal injection of 20 g/L 2,2,2-tribromoethanol at a concentration of 0.1 mL/10 g. Confirm proper anesthetization as indicated by muscle relaxation, slow and steady breathing, loss of skin stimulation reflex, and disappearance of corneal reflex.</li>
	<li>Apply ophthalmic ointment with a Q-tip to prevent dry eyes.</li>
	<li>Perform the parabiosis procedure as previously described5.
	<ol>
		<li>Place the mice in the supine position. Thoroughly shave the left side of one mouse and the right side of the other mouse starting at approximately 1 cm above the elbow to 1 cm below the knee with an electric shaver. Use depilatory cream to totally clear the fur on the shaved skin.</li>
		<li>Wipe the shaved areas with iodophor. Place the mice on a heated pad covered by a sterile pad.</li>
		<li>Create longitudinal skin incisions starting from 0.5 cm above the elbow to 0.5 cm below the knee joint using a pair of sharp scissors on each animal&#39;s shaved side.</li>
		<li>Detach the skin from the subcutaneous fascia gently following the incision.</li>
		<li>Connect the olecranon and knee of the parabiont with a 3-0 suture.</li>
		<li>Suture the shaved skin with a continuous 5-0 suture.</li>
	</ol>
	</li>
	<li>Inject 0.5 mL of 0.9% NaCl subcutaneously to each mouse to prevent dehydration.</li>
	<li>Inject tramadol (10 mg/25 g/day) intramuscularly to each mouse to relieve pain.</li>
</ol>
3. Validation of circulation chimerism
<ol>
	<li>Glucose fluctuation method 
	NOTE: Verify the successful construction of circulation chimerism between parabionts using the glucose fluctuation method (no fasting) on the 10th day after parabiosis surgery.
	<ol>
		<li>Anesthetize the parabionts by intraperitoneal injection of 20 g/L 2,2,2-tribromoethanol to each mouse at a concentration of 0.1 mL/10 g.</li>
		<li>Fix the donor mice in a Venous visual-mouse tail fixator.</li>
		<li>Rub the caudal veins in the flank of one of the parabiont&#39;s tail with a cotton ball soaked in 70&#8722;75% alcohol to clean the tail and dilate the blood vessels.</li>
		<li>Hold a 1.0 mL syringe containing glucose in the right hand and keep the needle parallel to the vein (less than 15&#176;).</li>
		<li>Insert the needle at a position approximately 2&#8722;4 cm from the tail tip.</li>
		<li>Inject 100 &#181;L of glucose (1.2 g/kg) into the donor within 10 s. 
		NOTE: The term donor refers to the parabiont that receives the glucose injection through the tail vein. The recipient is the other parabiont, which does not receive glucose directly.</li>
		<li>Clean the toes with iodophor. Cut off the toes of the donor and recipient mice with a scissor and collect a drop of blood at different time points after the injection of glucose (1 min, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, and 60 min). Remove the blood clot at each collection time point to avoid more damage. 
		NOTE: The volume of collected blood was 10-25 ul for one test, and 90-225 ul in total.</li>
		<li>Drip the blood into the center of glucometer test strips for glucose level detection.</li>
	</ol>
	</li>
	<li>Use Evan&#39;s blue Counterstain as a positive control3.
	<ol>
		<li>Inject 200 &#181;L of 0.5% Evan&#39;s blue Counterstain intraperitoneally into the donor mouse.</li>
		<li>2 h later, euthanize the parabionts by intraperitoneal injection of 20 g/L 2,2,2-tribromoethanol to each mouse at a concentration of 0.2 mL/10 g, and collect blood from both parabionts by cardiac puncture.</li>
		<li>Centrifuge the blood samples at 916 x g for 15 min.</li>
		<li>Collect serum from the supernatant.</li>
		<li>Dilute the serum with 0.9% NaCl at 1:50.</li>
		<li>Measure the absorbance of the diluted serum samples at 620 nm with a spectrophotometer.</li>
	</ol>
	</li>
</ol>

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The authors have nothing to disclose.

Parabiosis refers to the surgical technique of connecting two living animals to establish a common vascular system by experimental means6,7,8. The advantage of this model is that the substances produced by a single individual can act on both animals at the same time. Thus, the parabiosis model can be used to explore the role of a substance or factor in a related disease, producing many meaningful and innovative conclusions. In v...

Parabiosis is a modeling method in which two living organisms are joined together surgically and develop as a single physiological system with a shared circulatory system1. Such models have been widely used for studying physiology owing to the advantage that the substances produced by a single individual can act on both animals at the same time via the shared circulatory system. Since the mid-1800s when parabiotic experiments were pioneered by Paul Bert2, the methods for constructing parabiotic models have become standardized. However, a straightforward and convenient method for verifying the successful establishment of blood chimerism has been missing. It has been reported that cross-circulation can be successfully assessed by intraperitoneally injecting 0.5% Evans blue dye in one of the parabionts followed by measurement of the absorbance of Evans blue in the blood of both parabionts with a microplate reader3. Another method requires a specific mouse breed that contains CD45.1+- and CD45.2+-labeled monocytes in each parabiont. Cell cytometry is then used to determine blood chimerism by measuring the frequency of the two markers in monocytes from spleen or blood4. However, these methods are often lethal or cumbersome to the animals, and a safe and simple method for quick and reliable verification of parabiotic models is highly desirable. In this study, we established a new method for this purpose, which was validated in a mouse model of parabiosis. Glucose concentration in blood samples drawn from a tail vein is measured using a glucometer, and the pattern of changes of glucose level in donor and recipient mice is considered an indication of circulation chimerism. We named this method the &#34;glucose fluctuation method&#34;. The application of this validation method is not limited to mice but could be extended to diverse pathological models except for those with serious dysregulation of glucose metabolism. The procedure is simple, timesaving, and safe.

<table><tbody><tr><td>curved forceps</td><td>JZ surgical Instruments, China</td><td>J31340</td><td></td></tr><tr><td>fine scissors</td><td>JZ surgical Instruments, China</td><td>WA1030</td><td></td></tr><tr><td>needle forcep</td><td>JZ surgical Instruments, China</td><td>60017961</td><td></td></tr><tr><td>2.5 mL syringes</td><td>Agilent, USA</td><td>5182-9642</td><td></td></tr><tr><td>Tribromoethano</td><td>Sigma-Aldrich, USA</td><td>T48402-5G</td><td></td></tr><tr><td>penicillin</td><td>Solarbio, China</td><td>IP0150</td><td></td></tr><tr><td>tramadol</td><td>Yijishiye, China</td><td>YJT712520</td><td></td></tr><tr><td>glucometer</td><td>Roche Diabetes Care, Indiana</td><td>Accu-Chek Active test strips</td><td></td></tr><tr><td>Evan&#039;s blue Counterstain</td><td>Solarbio, China</td><td>G1810</td><td></td></tr><tr><td>depilatory cream</td><td>Nair, USA</td><td>LL9161</td><td></td></tr><tr><td>Warming Blanket (Heating pad)</td><td>Kent Scientific Corp, USA</td><td>TP-22G</td><td></td></tr><tr><td>Electrical shaver</td><td>Codos, China</td><td>CP-5000</td><td></td></tr><tr><td>3-0,5-0&lt;br/&gt; surgical suture</td><td>Shanghai Medical Suture Needle Factory, China</td><td>SYZ 3-0#, SYZ 5-0#</td><td></td></tr></tbody></table>

detecting establishment of shared blood supply in parabiotic mice by caudal vein glucose injection

Parabiosis is an experimental method for surgically combining two parallel animals along the longitudinal axis of the body. We present a protocol for detecting the successful establishment of blood chimerism in parabionts by a caudal vein injection of glucose. Parabiotic mice were constructed. Glucose was injected into the donor mouse through the tail vein, and the fluctuation of blood glucose level was measured in both mice using a blood glucometer at different time points. Our results showed that after glucose injection, the blood glucose level in donor mice increased sharply after 1 min and decreased slowly thereafter. Meanwhile, the blood glucose level of the recipient mice peaked 15 min after injection. Similar results were obtained with Evans blue, used as a positive control for glucose. The synchronous fluctuation of blood glucose levels indicates that blood flow between the two mice was established successfully.

In six donor mice, blood glucose levels sharply increased to 26.5 &#181;mol/L (173% increase) at an average of 1 min after the injection of 100 &#181;L of glucose (1.2 g/kg) through the tail vein and then gradually decreased to 13.3 &#181;mol/L at 60 min. In recipient mice, blood glucose slowly increased after injection and reached the first peak level at 15 min (47% increase, 12.2 &#181;mol/L). Based on the above results, the standard for circulation chimerism was set as follows: 1) a sh...

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Detecting Establishment of Shared Blood Supply in Parabiotic Mice by Caudal Vein Glucose Injection

Here we describe a new method of detecting successful establishment of shared blood circulation of two parabionts through a caudal vein injection of glucose, which causes minimal damage and is not fatal to the parabionts.

Parabiosis is an experimental method for surgically combining two parallel animals along the longitudinal axis of the body. We present a protocol for ...

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8.3K Views.  Harbin Medical University. Here we describe a new method of detecting successful establishment of shared blood circulation of two parabionts through a caudal vein injection of glucose, which causes minimal damage and is not fatal to the parabionts.

Video: Detecting Establishment of Shared Blood Supply in Parabiotic Mice by Caudal Vein Glucose Injection

A Double Humanized BLT-mice Model Featuring a Stable Human-Like Gut Microbiome and Human Immune System

Humanized mice (hu-mice) that feature a functional human immune system have fundamentally changed the study of human pathogens and disease. They can be used to model diseases that are otherwise difficult or impossible to study in humans or other animal models. The gut microbiome can have a profound impact on human health and disease. However, the murine gut microbiome is very different than the one found in humans. &#160;There is a need for improved pre-clinical hu-mice models that have an engrafted human gut microbiome. Therefore, we created double hu-mice that feature both a human immune system and stable human-like gut microbiome. NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice are one of the best animals for humanization due to their high level of immunodeficiency. However, germ-free NSG mice, and various other important germ-free mice models are not currently commercially available. Further, many research settings do not have access to gnotobiotic facilities, and working under gnotobiotic conditions can often be expensive and time consuming. Importantly, germ-free mice have several immune deficiencies that exist even after the engraftment of microbes. Therefore, we developed a protocol that does not require germ-free animals or gnotobiotic facilities. To generate double hu-mice, NSG mice were treated with radiation prior to surgery to create bone-marrow, liver, thymus-humanized (hu-BLT) mice. The mice were then treated with broad spectrum antibiotics to deplete the pre-existing murine gut microbiome. After antibiotic treatment, the mice were given fecal transplants with healthy human donor samples via oral gavage. Double hu-BLT mice had unique 16S rRNA gene profiles based on the individual human donor sample that was transplanted. Importantly, the transplanted human-like microbiome was stable in the double hu-BLT mice for the duration of the study up to 14.5 weeks post-transplant.

We describe a novel method for generating double humanized BLT-mice that feature a functional human immune system and a stable engrafted human-like gut microbiome. This protocol can be followed without the need for germ-free mice or gnotobiotic facilities.

Humanized mice (hu-mice) that feature a functional human immune system have fundamentally changed the study of human pathogens and disease. They can be ...

Biochemistry

Parabiosis in Mice: A Detailed Protocol

Parabiosis is a surgical union of two organisms allowing sharing of the blood circulation. Attaching the skin of two animals promotes formation of microvasculature at the site of inflammation. Parabiotic partners share their circulating antigens and thus are free of adverse immune reaction. First described by Paul Bert in 18641, the parabiosis surgery was refined by Bunster and Meyer in 1933 to improve animal survival2. In the current protocol, two mice are surgically joined following a modification of the Bunster and Meyer technique. Animals are connected through the elbow and knee joints followed by attachment of the skin allowing firm support that prevents strain on the sutured skin. Herein, we describe in detail the parabiotic joining of a ubiquitous GFP expressing mouse to a wild type (WT) mouse. Two weeks after the procedure, the pair is separated and GFP positive cells can be detected by flow cytometric analysis in the blood circulation of the WT mouse. The blood chimerism allows one to examine the contribution of the circulating cells from one animal in the other.

Parabiotic joining of two organisms leads to the development of a shared circulatory system. In this protocol, we describe the surgical steps to form a parabiotic connection between a wild-type mouse and a constitutive GFP-expressing mouse.

Parabiosis is a surgical union of two organisms allowing sharing of the blood circulation. Attaching the skin of two animals promotes formation of ...

Medicine

ICSI-ET Mouse Model to Study Long-Term Impacts on Glucose Metabolism

Monitoring Blood Glucose in Mouse Offspring After Intracytoplasmic Sperm Injection

Human lifespan is considerably long, while mouse models can simulate the entire human lifespan in a relatively short period, with one year of mouse life roughly equivalent to 40 human years. Intracytoplasmic sperm injection (ICSI) is a commonly used assisted reproductive technology in clinical practice. However, given its relatively recent emergence about 30 years ago, the long-term effects of this technique on human development remain unclear. In this study, we established the ICSI combined with embryo transfer (ET) method using a mouse model. The results demonstrated that normal mouse sperm, after undergoing in vitro culture and subsequent ICSI, exhibited a fertilization rate of 89.57% and a two-cell rate of 87.38%. Following ET, the birth rate of offspring was approximately 42.50%. Furthermore, as the mice aged, fluctuations in glucose metabolism levels were observed, which may be associated with the application of the ICSI technique. These findings signify that the mouse ICSI-ET technique provides a valuable platform for evaluating the impact of sperm abnormalities on embryo development and their long-term effects on offspring health, particularly concerning glucose metabolism. This study provides important insights for further research on the potential effects of the ICSI technique on human development, emphasizing the necessity for in-depth investigation into the long-term implications of this technology.

Author Spotlight: Exploring the Long-Term Health Impacts of Intracytoplasmic Sperm Injection on Offspring

Here, we present a protocol to establish an intracytoplasmic sperm injection (ICSI)-embryo transfer (ET) mouse model, allowing us to observe age-related changes in glucose metabolism that may be attributed to ICSI, providing insights into its potential long-term impacts on human development.

Human lifespan is considerably long, while mouse models can simulate the entire human lifespan in a relatively short period, with one year of mouse life ...

Developmental Biology

Mouse Model for Pancreas Transplantation Using a Modified Cuff Technique

Mouse models have several advantages in transplantation research, including easy handling, a variety of genetically well-defined strains, and the availability of the widest range of molecular probes and reagents to perform in vivo as well as in vitro studies. Based on our experience with various murine transplantation models, we developed a heterotopic pancreas transplantation model in mice with the intent to analyze mechanisms underlying severe ischemia reperfusion injury-associated early graft damage. In contrast to previously described techniques using suture techniques, herein we describe a new procedure using a non-suture cuff technique. 
In recent years, we have performed more than 300 pancreas transplantations in mice with an overall success rate of &gt;90%, a success rate never described before in mouse pancreas transplantation. The backbone of this non-suture cuff technique for graft revascularization consists of two major steps: (I) pulling the recipient vessel over a polyethylene/polyamide cuff and fixing it with a circumferential ligature, and (II) placing the donor vessel over the everted recipient vessel and fixing it with a second circumferential ligature. The resultant continuity of the endothelial layer results in less thrombogenic lesions with high patency rates and, finally, high success rates.
In this model, arterial anastomosis is achieved by pulling the abdominal aorta of the donor graft over the everted common carotid artery of the recipient animal. Venous drainage of the graft is achieved by pulling the portal vein of the graft over the everted external jugular vein of the recipient. This manuscript provides details and crucial steps of the organ recovery and organ implantation procedures, which will allow researchers with microsurgical skills to perform the transplantation successfully in their laboratories.

Among abdominal solid organ transplantation, pancreatic grafts are prone to develop severe ischemia reperfusion injury-associated graft damage, leading eventually to early graft loss. This protocol describes a model of murine pancreas transplantation using a non-suture cuff technique, ideally suited for analyzing these early, deleterious damages.

Mouse models have several advantages in transplantation research, including easy handling, a variety of genetically well-defined strains, and the ...

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 ...

Establishing In Situ Closed Circuit Perfusion of Lower Abdominal Organs and Hind Limbs in Mice

Ex vivo perfusion is an important physiological tool to study the function of isolated organs (e.g. liver, kidneys). At the same time, due to the small size of mouse organs, ex vivo perfusion of bone, bladder, skin, prostate, and reproductive organs is challenging or not feasible. Here, we report for the first time an in situ lower body perfusion circuit in mice that includes the above tissues, but bypasses the main clearance organs (kidney, liver, and spleen). The circuit is established by cannulating the abdominal aorta and inferior vena cava above the iliac artery and vein and cauterizing peripheral blood vessels. Perfusion is performed via a peristaltic pump with perfusate flow maintained for up to 2 h. In situ staining with fluorescent lectin and Hoechst solution confirmed that the microvasculature was successfully perfused. This mouse model can be a very useful tool for studying pathological processes as well as mechanisms of drug delivery, migration/metastasis of circulating tumor cells into/from the tumor, and interactions of immune system with perfused organs and tissues.

A protocol is described for in situ perfusion of the mouse lower body, including the bladder, the prostate, sex organs, bone, muscle and foot skin.

Ex vivo perfusion is an important physiological tool to study the function of isolated organs (e.g. liver, kidneys). At the same time, due to the small ...

Improved Blood Sampling Technique to Assess Gut Microbial Metabolites in Mice

Sequential Blood Collection from Inferior Vena Cava Followed by Portal Vein to Evaluate Gut Microbial Metabolites in Mice

Gut microbial products are known to act both locally within the intestine and get absorbed into circulation, where their effects can extend to numerous distant organ systems. Short-chain fatty acids (SCFA) are one class of metabolites produced by gut microbes during the fermentation of indigestible dietary fiber. They are now recognized&#160;as important contributors to how the gut microbiome influences extra-intestinal organ systems via the gut-lung, gut-brain, and other gut-organ axes throughout the host. SCFAs are absorbed from the colon, through intestinal tissue,&#160;into the portal vein (PV). They then pass through the liver, and are consumed in various organs such as the brain, muscle, adipose tissue, and lungs. SCFAs are most easily measured in the expelled fecal material however, more accurate measurements have been obtained from intra-colonic fecal contents. Here we propose that sampling PV and systemic circulating plasma of a single subject may be preferable for studying the&#160;absorption, transport, and systemic levels of SCFAs in mice. We present a new technique for efficient blood sampling from the PV and inferior vena cava (IVC) that allows for the collection of relatively large volumes of blood from the portal and systemic circulations. This is accomplished by ligating the PV, thereby allowing&#160;for the dilation or enlargement of the PV as it backfills from the mesenteric veins that drain into it. Using this method, we were able to improve the rate of successful collection as well as the total amount of blood collected (up to 0.3 mL from IVC and 0.5 mL from PV).

Author Spotlight: Gut Microbiome-Lung Tissue Communication Through Short-Chain Fatty Acid Analysis

The protocol demonstrates a method to collect blood from portal veins and inferior vena cava from mice sequentially to evaluate the production and absorption of gut microbial metabolites.

Gut microbial products are known to act both locally within the intestine and get absorbed into circulation, where their effects can extend to numerous ...

Immunology and Infection

Blood Circuit Reconstruction in an Abdominal Mouse Heart Transplantation Model

The surgical technique of heterotopic abdominal heart transplantation in mice is a standard model for research in transplantation immunology. Here, the established technique for a modified blood circuit reconstruction in a heterotopic abdominal heart transplantation model is presented. This method uses the intrathoracic inferior vena cava (IIVC) instead of the pulmonary artery of the donor heart for the anastomosis to the inferior vena cava of the recipient. It is facilitating and improving success rates for abdominal heart transplantation in mice.

A novel technique for blood circuit reconstruction in a heterotopic abdominal mouse heart transplantation model is demonstrated.

The surgical technique of heterotopic abdominal heart transplantation in mice is a standard model for research in transplantation immunology. Here, the ...

Minimizing Post-Infusion Portal Vein Bleeding during Intrahepatic Islet Transplantation in Mice

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the kidney capsule in most rodent preclinical islet transplantation studies. This model is commonly used because murine intrahepatic islet transplantation is technically challenging, and a high percentage of mice could die from surgical complications, especially bleeding from the injection site post-transplantation. In this study, two procedures that can minimize the incidence of post-infusion portal vein bleeding are demonstrated. The first method applies an absorbable hemostatic gelatin sponge to the injection site, and the second method involves penetrating the islet injection needle through the fat tissue first and then into the portal vein by using the fat tissue as a physical barrier to stop bleeding. Both methods could effectively prevent bleeding-induced mouse death. The whole liver section showing islet distribution and evidence of islet thrombosis post-transplantation, a typical feature for intrahepatic islet transplantation, were presented. These improved protocols refine the intrahepatic islet transplantation procedures and may help laboratories set up the procedure to study islet survival and function in pre-clinical settings.

Here we present refined surgical procedures on successfully performing intraportal islet transplantation, a clinically relevant but technically challenging surgical procedure, in mice.

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the ...

Surgical Installation of Hyperglycemic and Hypoglycemic Clamps in Mice

Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice

Diabetes mellitus (DM) is caused by insufficient insulin release from the pancreatic &#946;-cells (Type1 DM) and insulin sensitivity in muscles, liver, and adipose tissues (Type2 DM). Insulin injection treats DM patients but leads to hypoglycemia as a side effect. Cortisol and catecholamines are released to activate glucose production from the liver to recover hypoglycemia, called counter-regulatory responses (CRR). In DM research using rodent models, glucose tolerance tests and 2-deoxy-glucose injection are used to measure insulin release and CRR, respectively. However, blood glucose concentrations change persistently during experiments, causing difficulties in assessing net insulin release and CRR. This article describes a method in which blood glucose is kept at 250 mg/dL or 50 mg/dL in conscious mice to compare the release of insulin and CRR hormones, respectively.
Polyethylene tubing is implanted in the mice's carotid artery and jugular vein, and the mice are allowed to recover from the surgery. The jugular vein tubing is connected to a Hamilton syringe with a syringe pump to enable insulin or glucose infusion at a constant and variable rate. The carotid artery tubing is for blood collection. For the hyperglycemic clamp, 30% glucose is infused into the vein, and blood glucose levels are measured from the arterial blood every 5 min or 10 min. The infusion rate of 30% glucose is increased until the blood glucose level becomes 250 mg/dL. Blood is collected to measure insulin concentrations. For hypoglycemic clamp, 10 mU/kg/min insulin is infused together with 30% glucose, whose infusion rate is variable to maintain 50 mg/dL of blood glucose level. Blood is collected to measure counter-regulatory hormones when both glucose infusion and blood glucose reach a steady state. Both hyperglycemic and hypoglycemic clamps have the same surgical procedure and experimental setups. Thus, this method is useful for researchers of systemic glucose metabolism.

Author Spotlight: Investigating the Blood Glucose Homeostasis in Murine Brain Using a Cost-Effective Hyperglycemic And Hypoglycemic Clamp Technique

A hyperglycemic clamp is used for measuring insulin release with a maintained higher blood glucose concentration. A hypoglycemic clamp is for measuring glucose production induced by counter-regulatory responses. Both methods use the same surgical procedure. Here, we present a clamp technique to assess systemic glucose metabolism.

Diabetes mellitus (DM) is caused by insufficient insulin release from the pancreatic &#946;-cells (Type1 DM) and insulin sensitivity in muscles, liver, ...