Name: choosing the right route for compound delivery
Uploaded: 2016-09-15T11:02:02.000Z
Duration: 9 min 38 s
Channel: JoVE
Description: Compound delivery is a key part of many animal studies. The route used to give the compound can change how it is absorbed. Careful planning helps make sure the compound is delivered correctly. The substance itself also matters when a route is chosen. Its pH, viscosity, and concentration can all affect which method is best. These properties help guide the choice of administration route in a study.

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Life Science

Structure and Function

HS-LS1-2.

Compound Administration II

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经动物护理与使用委员会（IACUC）批准。所有操作均须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。
1. 局部应用
<ol>
	<li>在必要时应使用麻醉，以尽量减少准备和给药过程中的疼痛与痛苦。</li>
	<li>在涂抹任何药膏或乳膏前，应使用脱毛膏或剃除方法将施用区域的毛发完全清除。</li>
	<li>彻底清洁并干燥皮肤。</li>
	<li>使用棉签或直接滴加的方式将药物直接施用于皮肤，以避免接触技术人员。</li>
	<li>为获得最佳效果，应分多次涂抹薄层药膏或乳膏，而非一次性涂抹厚层。</li>
	<li>液体药物应分开毛发，将一滴药液施于暴露的皮肤上。</li>
	<li>进行局部给药时，由于动物可能通过理毛行为导致药物被吸收，存在全身吸收的风险。应采取预防措施，避免意外摄入或药物过早被清除。可使用小型颈圈或防护罩，防止动物接触受处理部位。在某些情况下，还需单独饲养，以防止笼内同伴动物相互理毛。</li>
	<li>仅在必要时且在最短必需时间内对动物进行单独饲养；由于单笼饲养是一种公认的应激源和潜在混杂因素，其使用必须有科学依据，并尽可能减少。</li>
</ol>
<img alt="动物实验准备；局部用药；实验室操作；小鼠；研究方法" src="/files/ftp_upload/10388/10388fig1v2.jpg" data-altupdatedat="1784001604000" data-alt="图1"> 
图1. 小鼠的局部给药。
2. 口服给药
<ol>
	<li>通过饲料或饮水向动物给予化合物时，必须根据体重计算每日最低剂量。可使用实验所用小鼠或大鼠品系的平均体重进行计算，除非特别要求对每只动物 individually 称重并分别计算剂量。</li>
	<li>例如，若目标剂量为每天每千克10毫克，动物平均体重为30克（即0.03千克），每笼饲养5只动物。</li>
	<li>将上述数值相乘，可得每笼每天所需的总剂量，最终结果为每笼每天1.5毫克。该剂量应存在于该笼动物每日平均摄入量中。</li>
	<li>对于需要精确测量食物和/或饮水摄入量的实验方案，动物必须单只饲养。</li>
	<li>动物必须能够持续获取饲料，且应根据研究要求在适当情况下提供自由采食（ad libitum feeding）。</li>
	<li>可根据实验需求定制特殊饲料或零食。
	<ol>
		<li>用配制好的饲料替代标准饮食，使动物在全天内持续摄入目标化合物。</li>
		<li>由于化合物可能不稳定，此类饲料可能需要比常规饲料更频繁地更换。</li>
	</ol>
	</li>
	<li>也可将物质溶解于饮水中进行给药，使动物在全天内持续摄入化合物。
	<ol>
		<li>在饮水中添加少量糖以提高适口性。具体添加量应根据小鼠对饮水的接受程度确定，应使用尽可能小的增量。</li>
		<li>更换饮水的频率取决于化合物的稳定性。某些物质可能对光敏感或随时间发生沉淀。</li>
	</ol>
	</li>
</ol>
3. 口服灌胃操作
小鼠使用18-20号×1.5英寸的直型或弯型给药针头。大鼠则使用16-18号×2-3英寸的直型或弯型给药针头。这些针头可为可重复使用的不锈钢针头，也可为一次性针头。一次性针头可具有金属或柔性塑料杆，末端带有硅胶头。
<ol>
	<li>根据测试溶液的体积和黏度选择合适的注射器，并将给药针连接到注射器上。对于黏稠液体的给药，建议使用鲁尔锁式注射器。此类注射器通常从3 cc规格开始，具有100 µl的刻度。但对于较小体积或需要精确小剂量给药的情况，可能并不适用。</li>
	<li>将注射器固定在针头上时，应确保无需转动针头即可读取筒身上的刻度。一旦针头插入食管，任何旋转动作都可能导致食管破裂，从而导致动物死亡。</li>
	<li>用适当体积的待给药物质填充注射器（最佳体积 = 5 ml/kg，最大体积 = 20 ml/kg）</li>
	<li>正确的固定对该操作至关重要。
	<ol>
		<li>通过抓住小鼠头部基部的皮肤并捏住颈背部皮肤来手动固定小鼠。重要的是，应使动物身体从头部到尾部保持在一条直线上。身体的任何扭转都会妨碍灌胃针进入食管。</li>
		<li>紧紧捏住颈背部皮肤，使头部的左右移动最小化。必须稳定后肢以防止身体旋转。</li>
		<li>对大鼠进行灌胃时，用每只手的食指和中指分别夹住其颈部两侧，手掌置于动物背部，拇指、无名指和小指环绕胸部，以防止动物前后移动。手指在颈部两侧的位置可防止大鼠转头。</li>
		<li>必须保持身体呈直线且无扭曲，以协助灌胃针顺利插入，避免对口腔、咽部、食管或胃造成损伤。</li>
		<li>确保头部无过度的左右晃动。</li>
		<li>可通过让后肢脚掌接触实验台面或笼盖来稳定后肢，防止身体旋转。</li>
		<li>在固定过程中，应持续监测动物，确保其呼吸正常。</li>
		<li>尽管口服灌胃通常在清醒动物中进行，但在动物高度应激、难以固定或需要重复给药的情况下，可考虑使用轻度麻醉；然而，由于其可能影响生理参数，使用时应谨慎评估。</li>
	</ol>
	</li>
	<li>物质的给药
	<ol>
		<li>给药前，从体外测量导管从头部到胸骨的长度，在鼻部位置做标记，插入时不得超过此点，以防胃穿孔。</li>
		<li>将针头弯曲面朝下，与颈部自然弯曲方向一致。从右侧或左侧口角处，沿门齿与臼齿之间以一定角度向咽后部插入针头。</li>
		<li>当针头进入口腔后，利用灌胃针将头部向后倾斜，直至鼻尖朝上。此步骤在使用直针时尤为重要。针头应能顺利滑入食管，切勿强行推进。若感到阻力，应将针头退出并重新尝试。</li>
		<li>当针头到达胃内位置后，轻柔地注入化合物。</li>
		<li>拔出针头时，确保弯曲针头不发生旋转。灌胃针应以与插入时相同的动作缓慢而轻柔地撤出。</li>
		<li>若动物开始挣扎，应立即取出给药针，并更牢固地固定动物。</li>
		<li>操作过程中，若动物出现发绀或呼吸困难，或有液体从口中流出，应立即移除给药针并将动物放回笼中。</li>
		<li>通常情况下，在对大鼠和小鼠进行灌胃，尤其是使用腐蚀性物质时，建议先给予少量液体以观察是否引发咳嗽，确认无误后再给予全部剂量。这样，若针头位置不正确，进入肺部的液体量较小，动物恢复的可能性更大。</li>
	</ol>
	</li>
</ol>
<img alt="实验动物操作技术；示意图；实验室研究；啮齿类动物给药操作。" src="/files/ftp_upload/10388/10388fig2v2.jpg" data-altupdatedat="1784001604000" data-alt="图 2"> 
图 2. 小鼠（左）和大鼠（右）的灌胃操作。
关键术语与定义 
给药途径主要有两种：肠内给药（通过消化道）和肠外给药（在消化道外给药）。给药途径的选择主要取决于研究的具体要求。肠外给药的主要优势在于化合物不会经历肝脏代谢，从而具有更高的生物利用度。然而，许多实验方案需要将化合物经口给予，以更好地模拟物质在自然状态下的摄入方式。最佳给药途径应根据受试化合物的性质来确定。 
口服给药：口服给药是人类最常用的药物给药方式，通常通过片剂、胶囊或液体药物形式实现。片剂和胶囊在啮齿类动物中难以使用，因此小鼠和大鼠常用的口服给药方式包括将化合物溶解于饮水中、使用含有受试化合物的特制饲料，或将化合物加入零食中。当通过饮水给药时，常在水中添加蔗糖以提高适口性。但蔗糖浓度需精确控制，以促进动物正常饮水，避免因过甜而导致饮水过量。 
多项研究表明，反复进行口服灌胃对小鼠和大鼠均会造成应激反应，同时也增加了动物护理人员的工作负担。目前已有商业化的饲料，其中含有常用剂量的化合物，例如用于清除啮齿类动物寄生虫的芬苯达唑。此外，一些公司还提供含有抗炎药、镇痛药、抗寄生虫药或抗生素的药用零食。为小鼠和大鼠生产配方饲料的公司可根据实验需求定制特殊试验饮食。许多实验室也自行配制含有蜂蜜、花生酱或果味明胶的零食用于给药。 
口服给药的精确性较差，因为化合物的摄入量取决于动物对食物或水的接受程度、化合物的稳定性以及笼内动物的数量。然而，如果实验对剂量精确性要求不高，这种非侵入性给药方式最有利于动物福利。 
口服灌胃：口服灌胃是一种更为精确的肠内给药方法，可将化合物在特定时间以指定体积直接送入动物胃内。但该技术需要经过专门培训才能成功实施。正确固定动物对该技术的成功至关重要。若头部和身体位置不当，可能导致口腔、咽部、喉部、气管、食管或胃部损伤。操作时必须牢固抓握动物，使其头部无法扭转，以防止上述损伤的发生。 
灌胃针有可重复使用和一次性两种类型。尽管一次性针头成本较高，但在对多个动物进行给药时可避免交叉污染的风险。灌胃针有多种规格，小鼠通常使用20-22号，大鼠使用18-20号。针头的选择取决于动物体型、液体体积以及待给药溶液的黏度。 
口服灌胃应在动物清醒状态下进行，以降低针头误入气管的风险。清醒动物保留吞咽反射和呕吐反射，有助于针头正确进入食管。一项研究表明，预先在灌胃针上涂覆蔗糖可诱发吞咽反射，并缩短针头通过食管所需的时间。 
局部给药：将局部作用药物直接施用于皮肤表面，通常仅作用于施用部位。这类药物可为乳膏、 lotion（乳液）、软膏、泡沫或凝胶等形式。由于动物倾向于舔舐施药区域，因此必须考虑药物经口摄入后的毒性。 
局部药物通常用于产生局部效应，但根据皮肤完整性、施药面积、药物浓度、暴露时间及脂溶性等因素，也可能发生全身吸收。皮肤水合程度高且角质层较薄时，会缩短吸收时间。 
在进行局部给药时，由于动物可能舔舐施药区域，存在全身吸收的风险。应采取预防措施，避免意外摄入或药物过早被清除。可使用小型颈圈或防护罩，防止动物接触受影响的身体部位。在某些情况下，还需单独饲养，以防止笼内同伴相互理毛。但单独饲养仅应在必要时进行，并尽可能缩短持续时间，因其可能成为应激源和潜在混杂因素，必须加以论证并尽量减少使用。 
本视频将帮助您解答的问题 
如果能够将化合物掺入饲料或饮水中，这是最安全且最人道的给药方式。口服灌胃虽能实现精确给药，但对动物造成较大应激，且需要较高的操作技术。局部给药在完成施药区域准备后，通常无需或仅需极少的动物固定。在选择给药途径时，应充分考虑其可能对动物造成的应激影响。

化合物给药 ii

来源：Kay Stewart，RVT，RLATG，CMAR；Valerie A. Schroeder，RVT，RLATG。美国印第安纳州圣母大学
化合物给药通常是动物实验的重要组成部分。为确保化合物正确递送，需要评估多种因素。给药途径会影响吸收机制。待引入物质的特性（如pH值、黏度和浓度）可能决定选择何种给药途径。

化合物给药 II

来源：Kay Stewart，RVT，RLATG，CMAR；Valerie A. Schroeder，RVT，RLATG。印第安纳州，圣母大学  
化合物给药通常是实验过程中不可或缺的一部分……

在许多实验中，为了更好地模拟自然暴露情况，化合物通过口服或局部给药途径给予动物。&#160; 
一种常见的口服方法是将化合物混入动物的饮用水或饲料中。通过添加少量蔗糖或其他调味剂，可改善适口性。&#160; 
可先使用10%的蔗糖浓度，并根据摄入量或经IACUC批准的实验方案及机构指南进行调整。 
添加蔗糖通常有助于提高摄入量；但应谨慎平衡，以支持正常摄食，避免引起过度饮水。&#160; 
另一种方法是通过特殊饲料给药。&#160; 
市面上已有含预混化合物的商用饲料，可实现无创且持续的给药。&#160; 
尽管该方法可减少操作带来的应激，但精确性较低，因为摄入量可能受摄食量、化合物稳定性以及每笼动物数量的影响。&#160; 
因此，该方法最适用于无需精确个体给药的情况。&#160; 
在可能的情况下，优先选择通过饲料或饮水等无创方式给药，以减少动物应激。 
对于饲料给药，应尽可能根据个体体重进行计算。 
对于群养动物，若动物体型相近，可根据笼内动物数量和平均每日摄食量进行笼水平的计算。 
例如，若目标剂量为每天每千克10毫克，动物平均体重为30克（即0.03千克），每笼有5只动物。&#160; 
将这些数值相乘，可得出每笼每天所需的总剂量。最终结果为每笼每天1.5毫克。该剂量应存在于该笼动物的平均每日摄入量中。&#160; 
若使用含药饲料或饮水，可能需要更频繁地更换，特别是当化合物不稳定、对光敏感或易发生沉淀时。 
当需要更精确的给药时，可采用口服灌胃法。该方法通过将定量体积的化合物直接送入胃内实现给药。 
根据机构指南选择合适的灌胃针。可选类型包括可重复使用的不锈钢针或一次性带硅胶头的柔性塑料饲管。&#160; 
推荐使用柔性塑料管，因其可降低食管损伤风险。 
对于小鼠，使用长约1.5英寸、规格为18–20号的针头；对于大鼠，使用长约2–3英寸、规格为16–18号的针头。&#160; 
针头和注射器的选择还应考虑给药体积和溶液黏度，对于黏稠溶液建议使用鲁尔锁式注射器。 
给药前，从体外测量饲管从头部到胸骨的长度，在鼻部位置做标记，并确保插入深度不超过该标记，以避免胃穿孔。安装注射器时，应确保无需旋转针头即可读取刻度。 
这一点非常重要，因为一旦针头进入食管，任何旋转动作都可能导致食管壁破裂，造成动物死亡。接下来，用注射器吸取准确体积的待给药溶液。 
灌胃操作仅应在具有完整吞咽反射的清醒动物上进行，并由经过培训的人员采用适当的固定技术操作，以最大程度减少动物痛苦和损伤风险。 
对于小鼠，应牢固抓住颈背部皮肤，同时保持身体呈直线，防止扭转，后肢应固定以避免旋转。对于大鼠，应固定肩部和胸部以控制其活动。 
固定后，将灌胃针弯曲面朝下，与颈部自然曲度对齐。将针头从门齿与臼齿之间的间隙插入，并引导其进入食管。&#160; 
轻轻将头部向上倾斜以促进导管通过。动物在导管推进过程中可能会出现吞咽动作。当导管到达胃部后，缓慢注入化合物，并在不旋转的情况下撤出针头。&#160; 
切勿强行插入；若感到阻力，应撤出并重新定位。整个操作过程中应持续监测动物呼吸。若观察到痛苦迹象、发绀或液体排出，应立即拔出针头并将动物放回笼中。 
另一种给药途径是局部给药，即将化合物直接施用于皮肤。常见剂型包括乳膏、 lotion、软膏、喷雾剂和凝胶。&#160; 
进行局部给药时，首先使用起效迅速的吸入性麻醉剂对动物进行麻醉，以减少应激和不适，并实现快速恢复。 
使用毛发剪刀去除给药区域的毛发，保持刀头平面紧贴皮肤，并逆毛发生长方向剃除，以避免划伤。&#160; 
用清水或机构批准的温和溶液轻轻清洁该区域，并用纱布擦干。&#160; 
使用棉签以多次薄层涂抹的方式施加物质，而非一次性涂抹厚层。 
局部制剂通常旨在产生局部效应，但根据皮肤状况、表面积、浓度、暴露时间及脂溶性等因素，也可能发生全身吸收。 
为防止动物因理毛行为导致意外摄入，应使用小型颈圈或保护性屏障。&#160; 
为防止笼内同伴相互理毛，仅在必要时且在最短必需时间内将动物单独饲养。&#160; 
除非有科学依据并经机构批准需长期单独饲养，否则应尽快将动物恢复群养。&#160; 
在任何单独饲养期间，应提供适当的环境丰富化措施，以保障动物福利。 
现在您已了解这些替代给药途径，接下来让我们看看它们在生物医学研究中的应用。 
口服灌胃的重要应用之一是精确给予物质以研究其对胃肠道的直接作用。在此研究中，科研人员使用该方法将一种经过改造的益生酵母直接递送至动物胃内。 
&#160;随后，他们解剖了小肠中的派尔集合淋巴结（即有序排列的淋巴滤泡），以研究所递送微生物的黏附情况。 
无创口服途径可用于模拟食源性感染的自然传播方式。在本实验中，科研人员建立了小鼠通过摄食污染食物感染单核细胞增生李斯特菌的模型。&#160; 
感染后，研究人员采集了小肠、结肠、脾脏、肝脏和胆囊等多种器官，以分析感染向这些组织的扩散情况。 
最后，部分研究人员关注紫外线辐射导致晒伤的机制。在此研究中，科研人员通过局部给药方式施加一种药理学物质，诱导表皮黑色素（一种紫外线防护剂）的生成。&#160; 
随后，他们采用类似于人类研究的方案，检测局部施用的制剂对紫外线辐射诱发红斑的防护效果。 
您刚刚观看了JoVE关于化合物给药方法的第二部分，内容涉及口服和局部给药。您现在应了解如何通过饲料或饮水对动物进行口服给药，以及如何实施更精确的口服灌胃给药。最后，您还应掌握局部给药的注意事项及其各种技术的应用。

Education

教育

JoVE Science Education

Basic Biology

基础生物学

Lab Animal Research

实验动物研究

Rodents

啮齿类动物

药物注射 II

choosing the right route for compound delivery

Compound delivery is a key part of many animal studies. The route used to give the compound can change how it is absorbed. Careful planning helps make sure the compound is delivered correctly.

The substance itself also matters when a route is chosen. Its pH, viscosity, and concentration can all affect which method is best. These properties help guide the choice of administration route in a study.

Choosing the Right Route for Compound Delivery

choosing-the-right-route-for-compound-delivery

rodent handling and restraint techniques

Minimizing Stress in Mouse and Rat Handling

Mouse and rat handling can create stress, even when the procedure is brief. Cage changing and other noninvasive tasks can raise heart rate, blood pressure, and serum corticosterone levels. These changes may last for several hours. Restraint for injections and blood withdrawal can also affect the animals and may influence scientific data. Because of this, proper training is needed when working with mice and rats. The goal is to reduce the effect of handling on the animals as much as possible. <br...

basic care procedures

Caring for Research Mice and Rats

Research mice and rats need careful housing, feeding, and handling. These animals make up over 90% of the animals used for biomedical research, so their care can strongly affect experiment results. Both immunocompetent animals, which have a normal immune response, and immunocompromised animals need proper support during studies. Some research animals have weakened immune systems and need extra steps to stay healthy. Common examples include naturally occurring immunocompromised mice and mice...

fundamentals of breeding and weaning

Mouse and Rat Breeding Methods

Mouse and rat breeding methods are used in biomedical research to supply animals for laboratory studies. Many research facilities buy mice from commercial breeders, but some also breed mice and rats in-house. In-house breeding can reduce costs and give researchers more options for their studies. Breeding animals in the facility also lets researchers manage genetics and timing. They can plan pregnancies to match research needs and work with embryos and newborns when needed. Mice and rats can be...

rodent identification i

Mice and Rats: Ear Tags and Punch Codes

Proper identification of laboratory mice and rats is important in biomedical research. The right animal must be used for each procedure and for data collection. Clear identification helps keep research records accurate and reliable. This page focuses on permanent identification methods for mice and rats. These methods include ear tags, ear punch codes, microchip implantation, tail tattoos for adult mice, and toe tattoos for neonates. Temporary methods such as dyes and marking pens can also be...

rodent identification ii

Rodent ID Methods for Accurate Records

Accurate rodent identification supports reliable animal records and data collection. Research animal records may include simple cage cards or a detailed database with full information on each animal. Individual identification is the key part of keeping those records correct. Mice and rats can be identified by several methods. These include tattooing, microchip placement, and temporary identification methods. Each method serves a different need in research animal management. The procedure also...

compound administration i

Rodent Injection Routes and Restraint

Rodent injection routes and restraint methods are key parts of compound administration in mice and rats. When a substance must be injected into an animal, the delivery route and the amount of compound must be chosen with care. The right choice helps match the dose to the protocol. Several factors guide the route of administration. These include the pH of the solution, the volume needed for the desired dose, and the viscosity of the solution. Viscosity means how thick or resistant to flow a...

compound administration ii

Compound delivery is a key part of many animal studies. The route used to give the compound can change how it is absorbed. Careful planning helps make sure the compound is delivered correctly. The substance itself also matters when a route is chosen. Its pH, viscosity, and concentration can all affect which method is best. These properties help guide the choice of administration route in a study.

compound administration iii

Specialized Injection Routes in Mice and Rats

Specialized injection routes in mice and rats are sometimes used when standard compound administration methods are not enough. Some study protocols call for less common routes such as intradermal, intranasal, and intracranial injections. These methods are used in laboratory animals and require careful technique. Intradermal injections place a compound into the skin. Intranasal injections deliver a compound through the nose. Intracranial injections are given into the brain. Because these...

compound administration iv

Specialized Injection Routes in Rodents

Specialized injection routes in laboratory mice and rats include intracardiac, footpad, and retro-orbital administration. These methods are used when a protocol calls for a route that is less common than standard compound delivery methods. Each route requires specialized training to perform correctly. Intracardiac injections deliver into the heart, footpad injections target the paw area, and retro-orbital injections are given around the eye region. Because these procedures are more technical,...

blood withdrawal i

Rodent Blood Collection Methods

Blood collection in mice and rats is a common part of research studies. The method used depends on how much blood is needed, how often samples must be taken, the animal's health, and the technician's skill level. This topic includes three blood withdrawal methods: retro-orbital sinus bleeds, initial tail snip bleeds, and intracardiac bleeds. Each method requires general anesthesia, which means the animal is made unconscious before the procedure begins.

blood withdrawal ii

Rodent Blood Sampling Methods

Blood collection from mice and rats can be done with several methods. The choice depends on the restraint needed, how invasive the procedure is, and whether a general anesthetic is required. These factors help determine which method is best for a given analysis. One older method uses the retro-orbital sinus cavity, which is located behind the eye. This approach has been debated because it may cause tissue damage or even blindness. For that reason, facial vein and submandibular vein bleeding...

anesthesia induction and maintenance

Laboratory Anesthesia and Pain Control

Laboratory anesthesia and pain control are important parts of veterinary care for research animals. The Guide for the Care and Use of Laboratory Animals says that pain assessment and pain relief must be part of that care. Anesthesia means the loss of feeling or sensation.

considerations for rodent surgery 

Aseptic Steps in Rodent Survival Surgery

Aseptic technique is essential for rodent survival surgery. It is used to keep the surgical site as clean as possible and to reduce contamination during the procedure. This approach includes patient preparation, surgeon preparation, and sterilization of instruments and other supplies. It also depends on a clean, controlled environment. Careful planning before surgery helps set up these steps for success. During the operation, animals need close monitoring. After the surgery, postoperative...

diagnostic necropsy and tissue harvest

Rat Necropsy for Tissue Collection

Rat necropsy is a key step for collecting organs and tissues at the end of many animal studies. These final samples are used for data collection time points and later testing. Because the samples are used for analysis, the way they are taken can affect sample quality. Careful collection methods help preserve the organs and tissues for testing. The method of euthanasia, or the procedure used to humanely end the animal's life, can also affect sample quality. This article outlines proper necropsy...

sterile tissue harvest

Aseptic Organ Collection in Rats and Mice

Aseptic organ collection in rats and mice is used to keep harvested tissues free from contamination. The process is important when tissues will be used for cell and tissue cultures. It also supports later protein and RNA analysis, as well as metabolic profiling of tissues. The transcript connects this work to the 3 R's, which were introduced in 1959 by W.M.S. Russell and R.L. Burch in The Principles of Humane Experimental Technique. The 3 R's are replacement, reduction, and refinement in the...

early intervention and pain management

早期干预与疼痛管理

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作均须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），且必须由经过培训的人员执行。  监测动物疼痛与痛苦的迹象 识别疼痛的早期征象对于符合伦理的动物研究至关重要。通常通过反映动物整体健康状况的行为、生理和物理参数来对动物进行常规监测。这些参数包括体重变化，持续性体重下降或未能维持预期的体重增长可能提示存在疼痛、疾病或慢性应激。体重评估需结合动物自身的基线数据及预期生长模式，而非仅依据单一数值。其他指标还包括筑巢行为，筑巢不良提示可能存在不适；以及水合状态，通常通过皮肤弹性或黏膜外观进行评估。例如，实验操作后停止理毛、体重下降或忽视筑巢的小鼠可能正处于疼痛状态。活动量减少、摄食或饮水模式改变以及社交互动减少等其他表现也提示动物福利受到损害。 使用小鼠面部表情量表评估疼痛 面部表情评分提供了一种更为敏感的疼痛评估方法。小鼠疼痛面容量表（Grimace...

humane euthanasia and confirmation of death in rodents

啮齿类动物的人道安乐死与死亡确认

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 啮齿类动物的仁慈终点是预先定义的临床、行为或生理指标，用于提示动物正在经历显著的疼痛、痛苦或健康状况下降。当观察到这些体征时，需及时采取干预措施，以最大程度减轻动物痛苦并保障其福利。  化学安乐死 该操作通常通过注射给予过量的批准麻醉剂来开始，具体选择取决于物种和研究方案。注射用麻醉剂（如戊巴比妥钠）可迅速抑制中枢神经系统活性。给药后，动物将失去意识和反射活动。深度麻醉会进一步发展为呼吸抑制，随后心脏和脑功能停止。在诱导前，轻柔操作和适当固定对于最大限度减少动物恐惧和应激至关重要。 吸入剂使用方法 此外，也可使用吸入性麻醉剂实施安乐死。将动物置于受控环境中，通过诱导室或面罩输送麻醉蒸气。诸如异氟烷或七氟烷等试剂可在动物感知疼痛前诱导其失去意识。该方法通过逐步镇静并尽量减少操作，从而降低动物的痛苦。<br...

habituation and positive reinforcement for rodent handling

啮齿类动物操作中的习惯化与正向强化

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经动物护理和使用委员会（IACUC）批准。所有操作必须遵守“3R”原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 习惯化和正向强化是有助于减少啮齿类动物在常规操作和实验过程中应激的优化策略。这些方法可改善动物福利，促进动物自愿配合，并减少可能影响研究结果的与应激相关的效应。 习惯化 习惯化是一种非联合型学习形式，指动物对重复出现的无威胁性刺激的反应随时间推移而逐渐减弱。通过反复接触操作人员、操作工具或实验程序环境，啮齿类动物会逐渐熟悉这些原本可能引发恐惧或回避行为的经历。习惯化训练应短暂、一致，并逐步引入，以使动物能够按照自身的节奏适应。 正向强化<br...

breeding management in rodent studies

啮齿类动物研究中的繁殖管理

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经机构动物护理和使用委员会（IACUC）批准。所有操作须遵守“3R”原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 繁殖管理通过减少不必要的动物生产，确保仅产生研究所需的动物数量，从而支持“3R”原则。有效的繁殖策略有助于减少过剩动物，提高动物资源的利用效率，同时保证科学目标的实现。 影响繁殖成功率的因素 育种计划应考虑影响种群繁殖效率的品系特异性及生物学变量，包括交配成功率、每窝产仔数、仔鼠存活率、基因型频率、性别分布、生育力以及繁殖寿命。准确预测这些变量有助于研究人员获得所需数量的实验动物，同时避免过度繁殖。 育种计算<br...

transport and acclimatization of rodents for research

实验用啮齿类动物的运输与适应性驯养

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经动物护理和使用委员会（IACUC）批准。所有操作须遵守“3R”原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 为科研目的运输啮齿类动物时，需采取相应措施，以尽量减少运输过程中的动物应激并保障动物福利，从而降低对实验结果的干扰。运输笼具应提供充足的通风、垫料、食物以及水合物来源（如凝胶补液包）。小鼠应轻柔操作，放入笼内时避免过度拥挤，以减少应激、攻击行为及受伤风险。笼具应牢固关闭，标明“活体动物”及相关运输信息，并覆盖透气材料，以减少外界刺激，同时确保良好的通风和温度控制。 运输与应激减轻 动物应通过机构指定的路线运输，避免经过公共区域和公共交通系统。公共区域会使动物暴露于过度的噪音、振动、陌生气味、温度波动和人类活动之中，这些因素均可能引发应激反应。运输过程中，应保持笼具直立、水平并固定稳妥，以防止不必要的移动和损伤，从而进一步降低与运输相关的应激。 笼具消毒与动物转移<br...

environmental enrichment for rodents

啮齿类动物的环境富集

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 环境丰容是指采用各种物品和方法来促进实验啮齿类动物的自然行为，改善其心理福祉，并提升动物福利。环境丰容应根据啮齿类动物的物种、品系、年龄、性别及研究设计进行定制，并依照机构的动物护理规程提供。 小鼠的环境富集 筑巢材料与隧道 对于小鼠而言，筑巢材料是最重要的环境丰富化资源之一。垫料和筑巢材料，如木丝、木屑、撕碎的纸张、纸条或巢垫块，均能强烈激发雄性和雌性小鼠的筑巢行为。筑巢行为还可作为健康和福利状况的重要指标，因为处于应激、患病或热应激状态的小鼠可能无法构建充分的巢穴。在笼内添加藏身处，例如隧道，可为小鼠提供安全的躲藏、休息和探索空间。 环境丰富化区域与啃咬物体<br...

rodents

Learn how route of administration, pH, viscosity, and concentration affect compound delivery in animal studies and help guide the best method.

Choosing the Right Route for Compound Delivery | JoVE K12

HS-LS1-3.

Kay Stewart

Valerie A. Schroeder

University of Notre Dame

Overview

Oral Dosing via Feed or Water

Oral Gavage Procedure

Topical Application

Applications

Summary

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

Visualizing Onion and Cheek Cells
ExpandImmediately before the experiment, wash and peel onion bulbs for the class.
Remove the entire brown outer skin and ...

Visualizing Onion and Human Cells
ExpandIn this experiment you will prepare different types of cells from a plant and animal, onion and human ...

What are Cells?

Cell Diversity

The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term &#34;cell&#34; based on the ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

The Central Dogma

The DNA Helix

Nucleic Acids

DNA as a Genetic Template

Structure of a Gene

A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the ...

Chromosome Structure

Base-pairing and DNA Repair

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Translation

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Protein and Protein Structures

Proteins: From Genes to Degradation

From DNA to Protein

The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of ...

Protein Folding

Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to ...

An Overview of Gene Expression

Gene expression is the complex process where a cell uses its genetic information to make functional products. This process is regulated at multiple ...

an-introduction-to-caenorhabditis-elegans

An Introduction to Caenorhabditis elegans

Caenorhabditis elegans is a microscopic, soil-dwelling roundworm that has been powerfully used as a model organism since the early 1970&rsquo;s.  It was ...

An Overview of Genetic Analysis

An organism&#8217;s physical traits, or phenotype, are a product of its genotype, which is the combination of alleles (gene variants) inherited from its ...

An Introduction to Cell Death

Necrosis, apoptosis, and autophagic cell death are all manners in which cells can die, and these mechanisms can be induced by different stimuli, such as ...

An Overview of Genetic Engineering

Genetic engineering &#8211; the process of purposefully altering an organism&#8217;s DNA &#8211; has been used to create powerful research tools and model ...

An Introduction to Cell Division

Cell division is the process by which a parent cell divides and gives rise to two or more daughter cells. It is a means of reproduction for single-cell ...

An Overview of Genetics and Disease

Many human diseases are associated with mutations or variations in genetic sequences. Some of these genetic variants are heritable, passed down from ...

an-introduction-to-cellular-and-molecular-neuroscience

An Introduction to Cellular and Molecular Neuroscience

Cellular and molecular neuroscience is one of the newest and fastest growing subdisciplines in neuroscience. By investigating the influences of genes, ...

Annexin V and Propidium Iodide Labeling

Staining with annexin V and propidium iodide (PI) provides researchers with a way to identify different types of cell death&#8212;either necrosis or ...

an-introduction-to-developmental-genetics

An Introduction to Developmental Genetics

Development is the complex process through which a single-celled embryo transforms into a multicellular organism. Developmental processes are guided by ...

Bacterial Transformation: Electroporation

The term &#x201C;transformation&#x201D; refers cellular ingestion of foreign DNA.  In nature, transformation can occur in certain types of bacteria.  In ...

an-introduction-to-molecular-developmental-biology

An Introduction to Molecular Developmental Biology

Molecular signals play a major role in the complex processes occurring during embryonic development. These signals regulate activities such as cell ...

bacterial-transformation-the-heat-shock-method

Bacterial Transformation: The Heat Shock Method

Transformation is the process that occurs when a cell ingests foreign DNA from its surroundings. Transformation can occur in nature in certain types of ...

an-introduction-to-saccharomyces-cerevisiae

An Introduction to Saccharomyces cerevisiae

Saccharomyces cerevisiae (commonly known as baker&rsquo;s yeast) is a single-celled eukaryote that is frequently used in scientific research.  S. ...

Cell Cycle Analysis

Cell cycle refers to the set of events through which a cell grows, replicates its genome, and ultimately divides into two daughter cells through the ...

An Introduction to Transfection

Transfection is the process of inserting genetic material, such as DNA and double stranded RNA, into mammalian cells. The insertion of DNA into a cell ...

Chromatin Immunoprecipitation

Histones are proteins that help organize DNA in eukaryotic nuclei by serving as &#8220;scaffolds&#8221; around which DNA can be wrapped, forming a complex ...

An Overview of Epigenetics

Since the early days of genetics research, scientists have noted certain heritable phenotypic differences that are not due to differences in the ...

community-dna-extraction-from-bacterial-colonies

Community DNA Extraction from Bacterial Colonies

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Luisa Ikner
Traditional methods of analysis ...

Cytogenetics

Cytogenetics is the field of study devoted to chromosomes, and involves the direct observation of a cell&#8217;s chromosomal number and structure, ...

embryonic-stem-cell-culture-and-differentiation

Embryonic Stem Cell Culture and Differentiation

Culturing embryonic stem (ES) cells requires conditions that maintain these cells in an undifferentiated state to preserve their capacity for self-renewal ...

DNA Gel Electrophoresis

DNA gel electrophoresis is a technique used for the detection and separation of DNA molecules. An electric field is applied to a gel matrix comprised of ...

Enzyme Assays and Kinetics

Enzyme kinetics describes the catalytic effects of enzymes, which are biomolecules that facilitate chemical reactions necessary for living organisms. ...

DNA Ligation Reactions

In molecular biology, ligation refers to the joining of two DNA fragments through the formation of a phosphodiester bond.  An enzyme known as a ligase ...

explant-culture-for-developmental-studies

Explant Culture for Developmental Studies

Explant culture is a technique in which living cells or tissues are removed from an embryo for continued development outside of the organism. This ex vivo ...

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

HS-LS1-1.

Choosing the Right Route for Compound Delivery

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