The authors acknowledge support from a Translational Breast Cancer Research Grant (14-60-26-BROC to AB) from the Breast Cancer Research Foundation and the American Association for Cancer Research.

Procedures using animal subjects have been approved by the Institutional Animal Care and Use Committee of the University of Texas at Austin.
1. Preoperative Preparation
<ol>
	<li>Record the body weight of each rabbit. As with all preclinical studies, monitor animal weights regularly to assess potential toxicity.</li>
	<li>Prior to anesthetizing the rabbit, fill a 50 mL conical tube with commercially available ultrasound gel and spin at 500 x g for 30 s; there should be no visible bubbles in the gel upon completion of the centrifugation.</li>
	<li>Administer glycopyrrolate subcutaneously at a dose of 0.1 mg/kg and acepromazine intramuscularly at a dose of 0.75 mg/kg. Wait 15-20 min for the sedative to take effect while monitoring vital signs and behavior. 
	NOTE: Glycopyrrolate is an anti-cholinergic agent that prevents bradycardia and reduces respiratory and GI secretions. Acepromazine is a sedative that serves as a premedication for anesthesia.</li>
	<li>Administer 35 mg/kg of ketamine and 5 mg/kg of xylazine subcutaneously as an anesthetic. However, as the operator becomes more experienced and can accomplish the intraductal delivery more rapidly, decrease the drug dosages to 15 mg/kg of ketamine and 3 mg/kg of xylazine subcutaneously; this will shorten the anesthesia time and the time required for the animal to recover from anesthesia.</li>
	<li>Check and document the heart rate, SPO2, temperature, respiratory rate, and mucus membrane color every 15 min. Apply eye lubricant to both eyes. 
	NOTE: Only personnel who have undergone appropriate training and have been approved by their institution&#39;s IACUC should administer or monitor anesthesia. The use of a veterinary anesthesia monitor can aid in acquiring vital signs and is recommended. The veterinary anesthesia monitor, however, does not replace the need to manually check the animal every 15 min. See the manufacturer&#39;s instructions for the proper use of a veterinary monitor.</li>
	<li>Verify the onset of anesthesia by a gentle toe pinch; the rabbit should be non-responsive before continuing.</li>
	<li>Carefully shave the caudal abdomen of the rabbit in the area around the third and fourth pairs of inguinal teats.</li>
	<li>With the majority of the hair removed, apply an over-the-counter hair removal cream to the shaved area. Remove the cream 10 min after application using damp paper towels wetted with warm water. 
	NOTE: Rabbit skin is very fragile/sensitive. The hair removal cream should be used for no more than 10 min. In fact, it is safer to try a &#8220;test spot&#8221; at 5 min and only leave on longer if test spot indicates a longer time period is needed.</li>
	<li>Wipe the area with alcohol-soaked gauze pads to clean the injection site.</li>
	<li>Place the rabbit on its dorsum in a v-shaped trough lined with a recirculating warm water blanket and an absorbent pad.</li>
</ol>
2. Preparation of the Contrast Agent
<ol>
	<li>Reconstitute the non-targeted contrast reagent according to the manufacturer&#39;s instructions. Pipette up and down gently to mix. 
	NOTE: The contrast agent used in this protocol is stable at room temperature for 4 - 6 h after reconstitution. Gently rock the vial between each retrieval. 
	NOTE: The volume of solution required will depend on the number of ducts to be injected. The rabbit has 4 ductal openings per teat, and 0.2 mL of solution is sufficient to fill one ductal tree of an adult New Zealand White Rabbit (Oryctolaguscuniculus). Thus, a total volume of 0.8 mL may be delivered to one mammary gland.</li>
</ol>
3. Intraductal Delivery
<ol>
	<li>Locate the appropriate teats to be injected; the 3rd and 4th pairs of inguinal teats are recommended, as they are easily visualized when the animal is positioned on its dorsum.</li>
	<li>Load 0.2 mL of sterile 0.9% saline into a 1 mL Luer-lock tuberculin syringe with a 22 G needle. Properly dispose of the 22 G needle once the saline is in the syringe and replace it with a sterile 25-gauge needle. Gently wipe the area with 85% isopropyl alcohol on a gauze pad.</li>
	<li>With the bevel of the needle up and the syringe parallel to the body of the animal, insert the bevel of the needle into the side of the teat and slowly inject 0.1-0.2 mL of saline; this will allow for better visualization of the ductal openings.</li>
	<li>Load 0.2 mL of injection solution into a 1 mL Luer-lock tuberculin syringe.</li>
	<li>Hold the teat gently with the thumb and index finger and lift it slightly to position it for the intraductal injection; a wearable ocular loupe may aid in visualizing the ductal openings.</li>
	<li>While maintaining the lifted position of the teat, carefully cannulate the duct of interest using a 25 G blunt-tip needle.</li>
	<li>After cannulation, gently twist the Luer-lock syringe on the hub of the blunt-tip infusion needle until it is locked in place.</li>
	<li>Lift the teat and inject the solution slowly to minimize potential damage caused by rapidly moving fluid within the duct; at no time should there be resistance when injecting the solution.</li>
</ol>
4. Ultrasound Imaging
<ol>
	<li>Apply a liberal amount of centrifuged ultrasound gel to the skin of the area of interest. Ensure that there are no bubbles in the gel, as these will compromise the image quality.</li>
	<li>Set the imaging depth to 6 mm. Place the 21-MHz transducer in contact with the gel and scan the area of interest in B-mode. Observe the contrast medium in the scanned region including the ductal opening and throughout the duct. 
	NOTE: These settings have been developed for use with a specific photoacoustic ultrasound machine. Refer to the Table of Materials for more details. It may be necessary to adjust the transmit power and imaging depth of other imaging systems to optimize mammary gland visualization.</li>
	<li>Remove the ultrasound gel from the animal&#39;s skin with a gauze pad.</li>
</ol>
5. Postoperative Care
<ol>
	<li>Observe the injection site: there should be no signs of trauma to the teat region or to the surrounding tissue, and swelling in the area surrounding the teat likely indicates a mammary fat pad injection rather than a successful intraductal injection.</li>
	<li>Place the rabbit in a sternal position. If needed, give 0.2 mg/kg of yohimbine intravenously to the marginal ear vein; this will reverse the effect of the xylazine and allow the animal to recover more quickly from anesthesia.</li>
	<li>Monitor the rabbit every 15 min throughout the recovery period until the animal is alert, responsive, and maintains a sternal position. 
	NOTE: This procedure should not result in tissue damage or swelling. If redness or swelling are observed, administer a dose of meloxicam 0.1-0.2 mg/kg PO once the animal is alert and able to take medication orally. Contact the institution&#39;s veterinary staff for further guidance.</li>
</ol>

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The authors have nothing to disclose.

This method of intraductal delivery to the rabbit mammary gland may be used for ultrasound contrast reagents and many other aqueous solutions, including vital dyes and therapeutics. Previous studies have demonstrated the intraductal delivery of hormones17,18,19. In rodent models, the intraductal delivery of nucleic acids8, chemotherapeutics6,7, an...

The intraductal delivery of therapeutic agents has been studied in rodent models and in early stage human trials3,4,5,6,11,12. A recent Phase I study demonstrated the safety and feasibility of intraductal carboplatin or intraductal pegylated liposomal doxorubicin in women awaiting mastectomy for the treatment of invasive cancer2.
Previous protocols for intraductal delivery have been developed for mouse and rat mammary glands6,7,8,9. For research purposes, intraductal tumor cell injections and the lentiviral vector delivery of oncogenes have also been performed in rodent models13,14,15,16. However, an ideal in vivo model of the intraductal delivery process should permit the development of novel classes of therapeutic compounds and facilitate preclinical assessment. Anatomical differences between rodents and humans have complicated the translation of these studies.
Unlike mice, in which each duct ends at a separate teat, the human breast consists of 5 to 9 independent ductal systems, each with a separate opening ending at the teat. Rabbit mammary glands harbor four independent ductal systems, each separately accessible through one of four orifices in a single teat. A rabbit model more closely matches the human anatomy and permits the study of intraductal drug delivery in a more relevant context.
Here, we use two techniques to assess intraductal delivery. The co-administration of a vital dye permits visualization through the skin and provides a simple and rapid confirmation of the method. For some applications, higher resolution mapping of the ducts may be preferred. We present here a protocol for ultrasound imaging of the ducts through the intraductal delivery of a non-targeted contrast reagent.

<table><tbody><tr><td>MicroMarker non-targeted contrast reagent</td><td>VisualSonics</td><td>VS-11694</td><td></td></tr><tr><td>Luer Lock 1 mL Syringes</td><td>BD</td><td>309628</td><td></td></tr><tr><td>Glycopyrrolate 0.2 mg/mL</td><td>Wedgewood Compounding Pharmacy</td><td>GLYCOP-INJ013VC</td><td>6 month shelf life, supply may be limited.&amp;nbsp;</td></tr><tr><td>Atropine Sulfate 0.5 mg/mL</td><td>Animal Health International</td><td>15320764</td><td>If glycopyrrolate is unavailable. Not to be combined with glycopyrrolate.</td></tr><tr><td>Ketamine HCL 100 mg/mL</td><td>Animal Health International</td><td>21250699</td><td>&lt;a href=&quot;http://www.animalhealthinternational.com/&quot;&gt;http://www.animalhealthinternational.com/&lt;/a&gt;</td></tr><tr><td>Acepromazine 10 mg/mL</td><td>Animal Health International</td><td>17640541</td><td></td></tr><tr><td>Xylazine 20 mg/mL</td><td>Animal Health International</td><td>20101547</td><td></td></tr><tr><td>Yohimbine 0.2 mg/mL</td><td>Animal Health International</td><td>14588965</td><td></td></tr><tr><td>Hair Removing Cream</td><td>Veet</td><td></td><td>Sensitive skin solution. Available through local retailers.</td></tr><tr><td>Blunt tip infusion needles</td><td>Sai Infusion Technology</td><td>B14-50</td><td>&lt;a href=&quot;http://www.sai-infusion.com/collections/blunt-needles&quot;&gt;http://www.sai-infusion.com/collections/blunt-needles&lt;/a&gt;</td></tr><tr><td>Veterinary Pulse Oximeter</td><td>EdanUSA</td><td>VE-H100B</td><td>&lt;a href=&quot;http://www.edanusa.com/Product/VE-H100B-Veterinary-Pulse-Oximeter.html&quot;&gt;http://www.edanusa.com/Product/VE-H100B-Veterinary-Pulse-Oximeter.html&lt;/a&gt;</td></tr><tr><td>Warm Water Pump</td><td>Gaymar</td><td>TP700</td><td></td></tr><tr><td>Warm Water Blanket</td><td>Animal Health International</td><td>21232696</td><td>Maxi-Therm Lite Warming Pads</td></tr><tr><td>Ultrasound system</td><td>VisualSonics</td><td>Vevo 2100</td><td></td></tr></tbody></table>

intraductal delivery to the rabbit mammary gland

Localized intraductal treatments for breast cancer offer potential advantages, including efficient delivery to the tumor and reduced systemic toxicity and adverse effects1,2,3,4,5,6,7. However, several challenges remain before these treatments can be applied more widely. The development and validation of intraductal therapeutics in an appropriate animal model facilitate the development of intraductal therapeutic strategies for patients. While the mouse mammary gland has been widely used as a model system of mammary development and tumorigenesis, the anatomy is distinct from the human gland. A larger animal model, such as the rabbit, may serve as a better model for mammary gland structure and intraductal therapeutic development. In contrast to mice, in which ten ductal trees are spatially distributed along the body axis, each terminating in a separate teat, the rabbit mammary gland more closely resembles the human gland, with multiple overlapping ductal systems that exit through separate openings in one teat. Here, we present minimally invasive methods for the delivery of reagents directly into the rabbit mammary duct and for visualization of the delivery itself with high-resolution ultrasound imaging.

Here, we show that the intraductal delivery of contrast reagents to the mammary ducts of a rabbit can be achieved without trauma to the tissue (Figure 2). In rabbits, four separate ductal systems converge at one teat and thus may be accessed and imaged individually using this method. Individual ductal openings are easily visualized; note the arrowhead marking a second ductal opening adjacent to the cannulated duct in Figure 2B.
<p class="jove_content"...

Watch this Scientific Journal Video about Intraductal Delivery to the Rabbit Mammary Gland at JoVE.com

Intraductal Delivery to the Rabbit Mammary Gland

Here, we describe a technique for the localized delivery of reagents to the rabbit mammary gland via an intraductal injection. In addition, we describe a protocol for visualization and the confirmation of delivery by high-resolution ultrasound imaging of contrast agents.

Localized intraductal treatments for breast cancer offer potential advantages, including efficient delivery to the tumor and reduced systemic toxicity and ...

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Bioengineering

9.3K Views.  The University of Texas at Austin. Here, we describe a technique for the localized delivery of reagents to the rabbit mammary gland via an intraductal injection. In addition, we describe a protocol for visualization and the confirmation of delivery by high-resolution ultrasound imaging of contrast agents. 

Video: Intraductal Delivery to the Rabbit Mammary Gland

Minimally Invasive Embryo Transfer and Embryo Vitrification at the Optimal Embryo Stage in Rabbit Model

Assisted reproductive techniques (ARTs), such as in vitro embryo culture or embryo cryopreservation, affect natural development patterns with perinatal and postnatal consequences. To ensure the innocuousness of ART applications, studies in animal models are necessary. In addition, as a last step, embryo development studies require evaluation of their capacity to develop full-term healthy offspring. Here, embryo transfer to the uterus is indispensable to perform any ARTs-related experiment.
The rabbit has been used as a model organism to study mammalian reproduction for over a century. In addition to its phylogenetic proximity to the human species and its small size and low maintenance cost, it has important reproductive characteristics such as induced ovulation, a chronology of early embryonic development similar to humans and a short gestation that allow us to study the consequences of ART application easily. Moreover, ARTs (such as intracytoplasmic sperm injection, embryo culture, or cryopreservation) are applied with suitable efficiency in this species.
Using the laparoscopic embryo transfer technique and the cryopreservation protocol presented in this article, we describe 1) how to transfer embryos through an easy, minimally invasive technique and 2) an effective protocol for long-term storage of rabbit embryos to provide time-flexible logistical capacities and the ability to transport the sample. The outcomes obtained after transferring rabbit embryos at different developmental stages indicate that morula is the ideal stage for rabbit embryo recovery and transfer. Thus, an oviductal embryo transfer is required, justifying the surgical procedure. Furthermore, rabbit morulae are successfully vitrified and laparoscopically transferred, proving the effectiveness of the described techniques.

Assisted reproductive techniques (ARTs) are in continuous evaluation to improve outcomes and reduce the associated risks. This manuscript describes a minimally invasive embryo transfer procedure with an efficient cryopreservation protocol that allows the use of rabbits as an ideal animal model of human reproduction.

Assisted reproductive techniques (ARTs), such as in vitro embryo culture or embryo cryopreservation, affect natural development patterns with perinatal ...

Developmental Biology

Intraductal Delivery and X-ray Visualization of Ethanol-Based Ablative Solution for Prevention and Local Treatment of Breast Cancer in Mouse Models

Breast cancer is the most prevalent cancer and the second-leading cause of cancer-related death for women in the USA. For high-risk women, prophylactic mastectomy is the most effective primary prevention strategy. Prophylactic mastectomy is an aggressive surgical procedure that completely removes the mammary epithelial cells from which breast cancer arises along with the surrounding tissue. We seek to develop a minimally invasive intraductal procedure as an alternative to prophylactic mastectomy to locally ablate the mammary epithelial cells before they can become malignant. We and others have developed an intraductal delivery procedure to reach and treat these epithelial cells in rodent models of breast cancer. While the mouse mammary gland with a single non-anastomosed ductal tree opening at the nipple has a much less complex and tortuous architecture than the human breast, chemically induced and genetically engineered mouse models of breast cancer are valuable to produce proof-of-concept studies of new preventative strategies. Here, we describe a procedure for intraductal delivery of an ethanol-based ablative solution containing micro-CT/X-ray tantalum-based contrast agent within the mouse mammary ductal tree for the therapeutic purpose of primary prevention of breast cancer. Intraductal delivery of aqueous reagents (e.g., cytotoxic compounds, siRNAs, AdCre) has been previously described in mouse models. Thus, we focus our protocol description on methodological modifications and unique experimental considerations for optimizing delivery of ethanol, for minimizing local and systemic side effects of ethanol administration, and for in vivo visualization of ductal tree filling via micro-CT/fluoroscopy imaging. Visualization of the ductal tree immediately after injection of a contrast-containing solution allows for confirmation of complete filling or unsuccessful outcomes such as underfilling or overfilling. This procedure can be applied for delivery and imaging of other ablative compounds aimed at either preventing tumor formation or locally treating early-stage tumors accessible via the ductal tree.

A method of intraductal injection of reagents for an ethanol-based ablative solution to the mouse mammary ductal tree for in vivo imaging and breast cancer prevention is described. Injection directly into the nipple opening allows for targeting mammary epithelial cells with minimal collateral tissue damage.

Breast cancer is the most prevalent cancer and the second-leading cause of cancer-related death for women in the USA. For high-risk women, prophylactic ...

Cancer Research

X-Ray Visualization of Intraductal Ethanol-Based Ablative Treatment for Prevention of Breast Cancer in Rat Models

There are still a limited number of primary interventions for prevention of breast cancer. For women at a high risk of developing breast cancer, the most effective intervention is prophylactic mastectomy. This is a drastic surgical procedure in which the mammary epithelial cells that can give rise to breast cancer are completely removed along with the surrounding tissue. The goal of this protocol is to demonstrate the feasibility of a minimally invasive intraductal procedure that could become a new primary intervention for breast cancer prevention. This local procedure would preferentially ablate mammary epithelial cells before they can become malignant. Intraductal methods to deliver solutions directly to these epithelial cells in rodent models of breast cancer have been developed at Michigan State University and elsewhere. The rat mammary gland consists of a single ductal tree that has a simpler and more linear architecture compared to the human breast. However, chemically induced rat models of breast cancer offer valuable tools for proof-of-concept studies of new preventive interventions and scalability from mouse models to humans. Here, a procedure for intraductal delivery of an ethanol-based ablative solution containing tantalum oxide nanoparticles as X-ray contrast agent and ethyl cellulose as gelling agent into the rat mammary ductal tree is described. Delivery of aqueous reagents (e.g., cytotoxic compounds, siRNAs, AdCre) by intraductal injection has been described previously in mouse and rat models. This protocol description emphasizes methodological changes and steps that pertain uniquely to delivering an ablative solution, formulation consideration to minimize local and systemic side effects of the ablative solution, and X-ray imaging for in vivo assessment of ductal tree filling. Fluoroscopy and micro-CT techniques enable to determine the success of ablative solution delivery and the extent of ductal tree filling thanks to compatibility with the tantalum-containing contrast agent.

A procedure for the delivery of a chemical ablative solution to the rat mammary ductal tree for image-guided preventive treatment of breast cancer is described. Mammary epithelial cells can be targeted with minimal collateral tissue damage through cannulation directly into the nipple opening and intraductal infusion of a 70% ethanol-based ablative solution.

There are still a limited number of primary interventions for prevention of breast cancer. For women at a high risk of developing breast cancer, the most ...

In Vivo Gene Delivery into Mouse Mammary Epithelial Cells Through Mammary Intraductal Injection

Mouse mammary glands comprise ductal trees, which are lined by epithelial cells and have one opening at the tip of each nipple. The epithelial cells play a major role in mammary gland function and are the origin of most mammary tumors. Introducing genes of interest into mouse mammary epithelial cells is a critical step in evaluating gene function in epithelial cells and generating mouse mammary tumor models. This goal can be accomplished through the intraductal injection of a viral vector carrying the genes of interest into the mouse mammary ductal tree. The injected virus subsequently infects mammary epithelial cells, bringing in the genes of interest. The viral vector can be lentiviral, retroviral, adenoviral, or adenovirus-associated viral (AAV). This study demonstrates how a gene of interest is delivered into mammary epithelial cells through mouse mammary intraductal injection of a viral vector. A lentivirus carrying GFP is used to show stable expression of a delivered gene, and a retrovirus carrying Erbb2 (HER2/Neu) is used to demonstrate oncogene-induced atypical hyperplastic lesions and mammary tumors.

In Vivo Gene Delivery into Mouse Mammary Epithelial Cells Through Mammary Intraductal Injection

The present protocol describes intraductal injection of viral vectors via the teat to deliver genes of interest into the mammary epithelial cells.

Mouse mammary glands comprise ductal trees, which are lined by epithelial cells and have one opening at the tip of each nipple. The epithelial cells play ...

Intranasal Immunization and Milk Collection in Studies of Maternal Immunization in New Zealand White Rabbits (Oryctolagus cuniculus)

Due to similarities in placentation and antibody transfer with humans, rabbits are an excellent model of maternal immunization. Additional advantages of this research model are the ease of breeding and sample collection, relatively short gestation period, and large litter sizes. Commonly assessed routes of immunization include subcutaneous, intramuscular, intranasal, and intradermal. Nonterminal sample collection for the chronological detection of the immunologic responses to these immunizations include the collection of blood, from both dams and kits, and milk from the lactating does. In this article, we will demonstrate techniques our lab has utilized in studies of maternal immunization in New Zealand White rabbits (Oryctolagus cuniculus), including intranasal immunization and milk collection.

Intranasal Immunization and Milk Collection in Studies of Maternal Immunization in New Zealand White Rabbits Oryctolagus cuniculus

This article describes and demonstrates the administration of intranasal vaccines and the collection of milk from lactating rabbits (Oryctolagus cuniculus) as a means to assess mucosal immunity in a translationally appropriate model of maternal immunization.

Due to similarities in placentation and antibody transfer with humans, rabbits are an excellent model of maternal immunization. Additional advantages of ...

Immunology and Infection

Intraductal Injection for Localized Drug Delivery to the Mouse Mammary Gland

Herein we describe a protocol to deliver various reagents to the mouse mammary gland via intraductal injections. Localized drug delivery and knock-down of genes within the mammary epithelium has been difficult to achieve due to the lack of appropriate targeting molecules that are independent of developmental stages such as pregnancy and lactation. Herein, we describe a technique for localized delivery of reagents to the mammary gland at any stage in adulthood via intraductal injection into the nipples of mice. The injections can be performed on live mice, under anesthesia, and allow for a non-invasive and localized drug delivery to the mammary gland. Furthermore, the injections can be repeated over several months without damaging the nipple. Vital dyes such as Evans Blue are very helpful to learn the technique. Upon intraductal injection of the blue dye, the entire ductal tree becomes visible to the eye. Furthermore, fluorescently labeled reagents also allow for visualization and distribution within the mammary gland. This technique is adaptable for a variety of compounds including siRNA, chemotherapeutic agents, and small molecules.

A protocol for the non-invasive intraductal delivery of aqueous reagents to the mouse mammary gland is described. The method takes advantage of localized injection into the nipples of mammary glands targeting mammary ducts specifically. This technique is adaptable for a variety of compounds including siRNA, chemotherapeutic agents and small molecules.

Herein we describe a protocol to deliver various reagents to the mouse mammary gland via intraductal injections. Localized drug delivery and knock-down of ...

Biology

Simplifying Transcutaneous Intratracheal Drug Delivery in the Newborn Preterm Rabbit

Intratracheal (IT) drug delivery allows the direct delivery of pharmaceutical substances to the lung, maximizing potential pulmonary benefit and minimizing systemic drug exposure. The transcutaneous technique is simple and allows for the IT delivery of substances to the lung of prematurely born rabbits shortly after birth. Newborn pups are anesthetized with inhaled Isoflurane before being placed in a supine position with the neck extended. The larynx is identified and stabilized before transcutaneous placement of a 26-gauge (G) catheter into the trachea. Following catheterization of the trachea, a 30 G blunt needle attached to a Hamilton syringe is introduced into the IT catheter and is used for delivering a precise volume into the trachea during spontaneous respiration. After the IT injection is completed, the needle and catheter are withdrawn, and the pup is allowed to recover from anesthesia. Transcutaneous IT injection delivers a large proportion of the injected substance to the lung, with the majority remaining in the lung 3 hours after the intervention. The injections are well tolerated from the day of birth and can be repeated for multiple consecutive days without influencing survival. This technique can be used to investigate the effect of pharmaceutical agents on lung development and in the prevention of neonatal lung injury in preterm rabbits.

Transcutaneous intratracheal injection allows for effective intrapulmonary drug delivery during spontaneous respiration. Single and multiple injections are well tolerated with no effect on survival. The technique is simple to perform and can examine the effect of substances on lung development and the prevention of lung injury in newborn rabbits.

Intratracheal (IT) drug delivery allows the direct delivery of pharmaceutical substances to the lung, maximizing potential pulmonary benefit and ...

Medicine

Pregnancy and Nursing Management for Embryo-Transferred and Genetically Modified Rabbits

With the advancement of scientific research, the demand for gene-edited rabbit models is increasing. However, there are limited pregnancy and feeding management systems for gene-edited rabbits, leading to low survival rates among gene-edited rabbits prepared by many inexperienced researchers. Therefore, proper guidance is essential. This article summarizes the pregnancy and feeding practices for genetically modified rabbits developed in the author's laboratory and outlines a set of fundamental processes. These include pregnancy diagnosis, antenatal care, midwifery, assisted breastfeeding, weaning, and other procedures, along with the rescue and care of weak newborn rabbits. Compared to the traditional natural childbirth and nurturing methods used in rabbit farms, this approach involves more refined management, requiring additional time and effort but significantly increasing the survival rate of suckling rabbits. The methods described in this article are suitable for most laboratory breeding scenarios involving gene-edited or embryo-transferred rabbits and provide a straightforward and effective reference for other researchers.

This protocol describes a pregnancy and feeding management technique for embryo-transferred and genetically modified rabbits, aimed at reducing newborn rabbit mortality and enhancing the preparation efficiency of gene-edited rabbits.

With the advancement of scientific research, the demand for gene-edited rabbit models is increasing. However, there are limited pregnancy and feeding ...

Intraductal Injection: Delivering Injection Mix into the Ducts of the Mouse Mammary Gland

Source: Xiang, D., et al. <a href="https://www.jove.com/v/59502/modeling-breast-cancer-via-an-intraductal-injection-cre-expressing">Modeling Breast Cancer via an Intraductal Injection of Cre-expressing Adenovirus into the Mouse Mammary Gland.</a> J. Vis. Exp (2019).
This video describes an intraductal injection technique where we deliver injection mix into the ducts of mouse mammary glands.

Source: Xiang, D., et al. Modeling Breast Cancer via an Intraductal Injection of Cre-expressing Adenovirus into the Mouse Mammary Gland. J. Vis. Exp ...

JoVE Encyclopedia of Experiments

Breast Cancer

Procedures and techniques

Rabbit Intraductal Injection: Localized Delivery of Solution of Interest into the Rabbit Mammary Gland

Source: Clark et. al., <a href="https://www.jove.com/v/55209/intraductal-delivery-to-the-rabbit-mammary-gland">Intraductal Delivery to the Rabbit Mammary Gland.</a> J. Vis. Exp. (2017).
In this video we describe a technique of administering a solution of interest into the mammary duct of a rabbit and confirm the delivery by high-resolution ultrasound imaging of contrast agents.

Source: Clark et. al., Intraductal Delivery to the Rabbit Mammary Gland. J. Vis. Exp. (2017).
In this video we describe a technique of administering a ...

Intraductal Delivery to the Rabbit Mammary Gland

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