Cette étude a été financée par les Instituts canadiens de recherche en santé et Génome Canada.JS détient bourses d&#39;aide salariale de la recherche médicale de l&#39;Alberta Heritage Foundationfor, Fondation des maladies du cœur du Canadaand l&#39;Association canadienne du diabète. Un merci spécial à M. David Wasserman et Bracy Bingle pour enseigner cette procédure pour le laboratoire Shearer.

<ol>
	<li>Halseth, A. E., Bracy, D. P., Wasserman, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitations+to+basal+and+insulin-stimulated+skeletal+muscle+glucose+uptake+in+the+high-fat-fed+rat.">Limitations to basal and insulin-stimulated skeletal muscle glucose uptake in the high-fat-fed rat.</a> Am J Physiol Endocrinol Metab. 279, E1064-E1071 (2000).</li><li>Halseth, A. E., Bracy, D. P., Wasserman, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitations+to+muscle+glucose+uptake+due+to+high+fat+feeding.">Limitations to muscle glucose uptake due to high fat feeding.</a> Am. J. Physiol. 279, E1064-E1071 (2000).</li><li>Muniyappa, R., Lee, S., Chen, H., Quon, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+approaches+for+assessing+insulin+sensitivity+and+resistance+in+vivo:+advantages,+limitations,+and+appropriate+usage.">Current approaches for assessing insulin sensitivity and resistance in vivo: advantages, limitations, and appropriate usage.</a> Am J Physiol Endocrinol Metab. 294, 15-26 (2008).</li><li>Cho, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insulin+resistance+and+a+diabetes+mellitus-like+syndrome+in+mice+lacking+the+protein+kinase+Akt2+(PKB+beta).">Insulin resistance and a diabetes mellitus-like syndrome in mice lacking the protein kinase Akt2 (PKB beta).</a> Science. 292, 1728-1731 (2001).</li><li>Dubois, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+SHP-1+protein+tyrosine+phosphatase+negatively+modulates+glucose+homeostasis.">The SHP-1 protein tyrosine phosphatase negatively modulates glucose homeostasis.</a> Nat Med. 12, 549-556 (2006).</li><li>Pacini, G., Thomaseth, K., Ahren, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contribution+to+glucose+tolerance+of+insulin-independent+vs.+insulin-dependent+mechanisms+in+mice.">Contribution to glucose tolerance of insulin-independent vs. insulin-dependent mechanisms in mice.</a> Am J Physiol Endocrinol Metab. 281, 693-703 (2001).</li><li>Herbach, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dominant-negative+effects+of+a+novel+mutated+Ins2+allele+causes+early-onset+diabetes+and+severe+beta-cell+loss+in+Munich+Ins2C95S+mutant+mice.">Dominant-negative effects of a novel mutated Ins2 allele causes early-onset diabetes and severe beta-cell loss in Munich Ins2C95S mutant mice.</a> Diabetes. 56, 1268-1276 (2007).</li><li>Maeda, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diet-induced+insulin+resistance+in+mice+lacking+adiponectin/ACRP30.">Diet-induced insulin resistance in mice lacking adiponectin/ACRP30.</a> Nat Med. 8, 731-737 (2002).</li><li>Potenza, M. A., Marasciulo, F. L., Tarquinio, M., Quon, M. J., Montagnani, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+spontaneously+hypertensive+rats+with+rosiglitazone+and/or+enalapril+restores+balance+between+vasodilator+and+vasoconstrictor+actions+of+insulin+with+simultaneous+improvement+in+hypertension+and+insulin+resistance.">Treatment of spontaneously hypertensive rats with rosiglitazone and/or enalapril restores balance between vasodilator and vasoconstrictor actions of insulin with simultaneous improvement in hypertension and insulin resistance.</a> Diabetes. 55, 3594-3603 (2006).</li><li>Ayala, J. E., Bracy, D. P., McGuinness, O. P., Wasserman, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Considerations+in+the+design+of+hyperinsulinemic-euglycemic+clamps+in+the+conscious+mouse.">Considerations in the design of hyperinsulinemic-euglycemic clamps in the conscious mouse.</a> Diabetes. 55, 390-397 (2006).</li><li>Wasserman, D. H., Ayala, J. E., McGuinness, O. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lost+in+translation.">Lost in translation.</a> Diabetes. 58, 1947-1950 (2009).</li></ol>

Des procédures ont été approuvées par l&#39;Université de Calgary et de protection des animaux Utiliser Comité et respecter par l&#39;Association canadienne pour les directives de science de laboratoire pour l&#39;expérimentation animale. Les auteurs n&#39;ont aucun conflit d&#39;intérêts ou les divulgations.

Initialement développé pour enquêter sur sensibilité à l&#39;insuline chez l&#39;homme, la procédure de fixation a été adapté à d&#39;autres espèces, y compris des rats de laboratoire et les souris. Étude des modèles animaux d&#39;insulino-résistance fournit une aide significative dans la compréhension de la physiopathologie de la sensibilité à l&#39;insuline et des pathologies associées ainsi que l&#39;identification des interventions thérapeutiques qui ont une valeur clinique 1,2. Plusieu...

<table border="1"><tbody><tr valign="top"><td> Nom du réactif </td><td> Société </td><td> Numéro de catalogue </td><td> Commentaires (optionnel) </td></tr><tr valign="top"><td> Tuyaux en polyéthylène Intramedic (PE-50) </td><td> Fisher Scientific </td><td> 14 à 170-12B </td><td> Diamètre intérieur de 0,58 mm (0,023 &quot;) x diamètre extérieur de 0,965 mm (0,038&quot;) </td></tr><tr valign="top"><td> Dow Corning Silastic tube de laboratoire </td><td> Fisher Scientific </td><td> 11 à 189-15C </td><td> Diamètre intérieur de 0,76 mm (0,030 &quot;) de diamètre x 1.65mm extérieur de (0,065&quot;) </td></tr><tr valign="top"><td> Tygon S-50-HL tubes médicaux </td><td> Harvard Apparatus </td><td> PY2 72-1251 </td><td> Diamètre intérieur de 3,2 mm (0,125 &quot;) de diamètre x 4,7 mm d&#39;Outer (0,1875&quot;) </td></tr><tr valign="top"><td> Loctite Super Glue </td><td> Grand &amp; Toy </td><td> 32237 </td><td> Gel de contrôle </td></tr><tr valign="top"><td> Stérile lame chirurgicale </td><td> VWR </td><td> BD371610 </td><td></td></tr><tr valign="top"><td> Courbé Micro pince à disséquer </td><td> George Tiemann &amp; Co. </td><td> 160-20 </td><td> x 2 </td></tr><tr valign="top"><td> Droit Micro pince à disséquer </td><td> George Tiemann &amp; Co. </td><td> 160-15 </td><td> x 2 </td></tr><tr valign="top"><td> Hémostatique courbée </td><td> George Tiemann &amp; Co. </td><td> 105-1135 </td><td> x 2 </td></tr><tr valign="top"><td> Hémostatique droite </td><td> George Tiemann &amp; Co. </td><td> 105-1130 </td><td> x 2 </td></tr><tr valign="top"><td> Gardes Astuce hémostatique </td><td> Robbins Instruments, Inc </td><td> 15.09-2-004 </td><td></td></tr><tr valign="top"><td> Ciseaux de chirurgie droites </td><td> George Tiemann &amp; Co. </td><td> 105-402 </td><td></td></tr><tr valign="top"><td> VENOJECT multi-échantillon Luer Adapter </td><td> Terumo Medical Products </td><td> 810127A </td><td> Calibre 21, 1 po </td></tr><tr valign="top"><td> Introducteur de cathéter stérile </td><td> Becton Dickinson </td><td> 406999 </td><td></td></tr><tr valign="top"><td> 14 aiguille de calibre Blunt </td><td> Becton Dickinson </td><td> 511310 </td><td> Calibre 14, 2 po </td></tr><tr valign="top"><td> Stérile suture chirurgicale </td><td> Johnson &amp; Johnson Medical Products </td><td> 1679H </td><td> Soie, taille 3-0 </td></tr><tr valign="top"><td> Non stériles suture chirurgicale </td><td> Angiotech Pharmaceuticals, Inc </td><td> SP116 </td><td> Soie, taille 4-0 </td></tr><tr valign="top"><td> Cotons-tiges </td><td> VWR </td><td> 10806-005 </td><td></td></tr><tr valign="top"><td> Tampons de gaze 4ply </td><td> VWR </td><td> CA43845-062 </td><td></td></tr><tr valign="top"><td> Clippers petits animaux sans fil </td><td> Harvard Apparatus </td><td> 729063 </td><td></td></tr><tr valign="top"><td> L&#39;isoflurane </td><td> Halocarbon Products Corp </td><td> IPN-45 </td><td></td></tr><tr valign="top"><td> Anesthésique panier </td><td> Benson Medical Industries, Inc </td><td></td><td></td></tr><tr valign="top"><td> L&#39;éthanol à 70% </td><td> Fisher Scientific </td><td> HC-1000 </td><td></td></tr><tr valign="top"><td> Solution antiseptique Betadine </td><td> Ouest Drug Distribution Centre Ltd </td><td> 105267 </td><td></td></tr><tr valign="top"><td> Modèle 11 Plus pompe seringue </td><td> Harvard Apparatus </td><td> 702208 </td><td></td></tr><tr valign="top"><td> Coupleurs tube acier inoxydable </td><td> Harvard Apparatus </td><td> 72-4434 </td><td> Calibre 23, 0,3 po </td></tr><tr valign="top"><td> Tubes en acier inoxydable Bouchons </td><td> Harvard Apparatus </td><td> 72-4436 </td><td> Calibre 23, 0,5 po </td></tr><tr valign="top"><td> Acier inoxydable Aiguilles Blunt </td><td> Instech Laboratories, Inc </td><td> LS22 </td><td> Calibre 22 </td></tr><tr valign="top"><td> 60 Degré Y Connecteurs </td><td> Petites pièces </td><td> STCY-22-05 </td><td> Calibre 22 </td></tr><tr valign="top"><td> CritSpin micro-hématocrite Centrifugeuse </td><td> Iris Sample Processing </td><td> CS12 </td><td></td></tr><tr valign="top"><td> Centrifugeuse Mini </td><td> Fisher Scientific </td><td> 05-090-100 </td><td></td></tr><tr valign="top"><td> Tubes à centrifuger Micro </td><td> VWR </td><td> 53550-778 </td><td></td></tr><tr valign="top"><td> Tubes à centrifuger 50ml polypropylène </td><td> VWR</td><td> 89004-364 </td><td></td></tr><tr valign="top"><td> 1ml Seringues en plastique Astuce Slip </td><td> Becton Dickinson </td><td> 309602 </td><td></td></tr><tr valign="top"><td> 3ml plastique Seringues Astuce Luerlok </td><td> Becton Dickinson </td><td> 309585 </td><td></td></tr><tr valign="top"><td> Injection anticoagulant de l&#39;héparine </td><td> Ouest Drug Distribution Centre Ltd </td><td> 102824 </td><td> Fabricant: LEO Pharma Inc Conc. 1000 UI </td></tr><tr valign="top"><td> Solution d&#39;EDTA </td><td> Promega Corp </td><td> V4231 </td><td> 0,5 M, pH 8,0 </td></tr><tr valign="top"><td> Saline </td><td> Ouest Drug Distribution Centre Ltd </td><td> ABB7983154 </td><td> Fabricant: Chlorure de sodium à 0,9% de Hospira </td></tr><tr valign="top"><td> Dextrose à 50% </td><td> Vétoquinol </td><td> 8DEX012D </td><td></td></tr><tr valign="top"><td> Humulin-R </td><td> Eli Lilly </td><td> HI-210 </td><td> 100U/ml </td></tr><tr valign="top"><td> Seringues à insuline 1ml </td><td> Becton Dickinson </td><td> 309311 </td><td></td></tr><tr valign="top"><td> Fisherbrand * Hémato-Seal scellant </td><td> Fisher Scientific </td><td> 02-678 </td><td></td></tr><tr valign="top"><td> Fisherbrand * microhématocrite Tubes capillaires </td><td> Fisher Scientific </td><td> 22-362-574 </td><td></td></tr><tr valign="top"><td> One Touch Ultra bandelettes de test </td><td> LifeScan, Inc </td><td> AW 085-314H </td><td></td></tr><tr valign="top"><td> One Touch Ultra compteur de la glycémie </td><td> LifeScan, Inc </td><td> AW 085-314B </td><td></td></tr><tr valign="top"><td> Sodium pentobarbital </td><td> Ceva Santé Animale </td><td> 1715 138 </td><td> Conc. 54.7mg/ml </td></tr><tr valign="top"><td> Red Tape Étiquetage de laboratoire </td><td> VWR </td><td> 89097-932 </td><td></td></tr><tr valign="top"><td> Blue Tape Étiquetage de laboratoire </td><td> VWR </td><td> 89097-936 </td><td></td></tr><tr valign="top"><td> Peser échelle </td><td> Fisher Scientific </td><td> 01-913-88 </td><td></td></tr><tr valign="top"><td> Vortex </td><td> VWR </td><td> 58815-234 </td><td></td></tr><tr valign="top"><td> Minuterie </td><td> VWR </td><td> 62344-641 </td><td></td></tr></tbody></table>

hyperinsulinemic-euglycemic clamp in the conscious rat

Diabète de type 2 (DT2) est l&#39;augmentation rapide de la prévalence. Caractérisés par une production d&#39;insuline insuffisante ou l&#39;impossibilité d&#39;utiliser l&#39;insuline produite, les résultats DT2 chez des niveaux élevés de glucose dans le sang. Le «étalon-or» dans l&#39;évaluation de sensibilité à l&#39;insuline est une pince hyperinsulinémique euglycémique ou pince-insuline. Dans cette procédure, l&#39;insuline est perfusée à un taux constant résultant en une baisse de la glycémie. Afin de maintenir la glycémie à un niveau constant, le glucose exogène (D50) est injecté dans la circulation veineuse. La quantité de glucose perfusée pour maintenir une homéostasie est révélateur de sensibilité à l&#39;insuline. Ici, nous montrons la procédure de serrage de base dans la chronique cathétérisés, débridée, le rat conscient. Ce modèle permet au sang d&#39;être recueillies avec un minimum de stress pour l&#39;animal. Après l&#39;induction de l&#39;anesthésie, une incision médiane est faite et les artère carotide commune gauche et droite veine jugulaire sont cathétérisés. Cathéters insérés sont rincés avec du sérum physiologique hépariné, puis extériorisé et sécurisé. Les animaux sont autorisés à récupérer pendant 4-5 jours avant les expériences, avec un gain de poids contrôlée quotidiennement. Seuls les animaux qui regagner du poids à la pré-chirurgie niveaux sont utilisés pour des expériences. Le jour de l&#39;expérience, les rats sont mis à jeun et connectés à des pompes contenant de l&#39;insuline et D50. Glycémie de base est évaluée à partir de la ligne artérielle et a utilisé un indice de référence tout au long de l&#39;expérience (euglycémie). Suite à cela, l&#39;insuline est perfusée à un taux constant dans la circulation veineuse. Pour correspondre à la baisse de la glycémie, D50 est perfusé. Si le taux de perfusion D50 est supérieur au taux d&#39;absorption, une augmentation de la glycémie va se produire. De même, si le taux est insuffisant pour correspondre à l&#39;ensemble du corps l&#39;absorption du glucose, une baisse se produira. Titrage de glucose se poursuit jusqu&#39;au lectures de glucose stables sont atteints. Les niveaux de glucose et des taux de perfusion de glucose au cours de cette période de stabilité sont enregistrés et signalés. Les résultats fournissent un indice de sensibilité d&#39;insuline du corps tout entier. La technique peut être affiné pour répondre aux exigences spécifiques d&#39;expérimentation. Il est en outre renforcée par l&#39;utilisation de traceurs radioactifs qui peuvent déterminer stimulée par l&#39;insuline des tissus spécifiques captation du glucose ainsi que l&#39;ensemble du glucose du corps.

Watch this Scientific Journal Video about Hyperinsulinemic-Euglycemic Clamp in the Conscious Rat at JoVE.com

Hyperinsulinemic-Euglycemic Clamp in the Conscious Rat

La pince hyperinsulinémique-euglycémique est le «gold standard» pour l&#39;évaluation de l&#39;action d&#39;insuline. L&#39;insuline est perfusée à un taux constant stimulant l&#39;absorption du glucose. La quantité de glucose exogène infusé pour contrer cette baisse est révélatrice de sensibilité à l&#39;insuline. Voici la procédure est effectuée sur une conscience, rat effrénée.

Hyperinsulinémique euglycémique-Clamp chez le rat conscient

Type 2 diabetes (T2D) is rapidly rising in prevalence. Characterized by either inadequate insulin production or the inability to utilize insulin produced, ...

hyperinsulinemic-euglycemic-clamp-in-the-conscious-rat

Research

JoVE Journal

Medicine

51.8K vues.  University of Calgary. La pince hyperinsulinémique-euglycémique est le «gold standard» pour l'évaluation de l'action d'insuline. L'insuline est perfusée à un taux constant stimulant l'absorption du glucose. La quantité de glucose exogène infusé pour contrer cette baisse est révélatrice de sensibilité à l'insuline. Voici la procédure est effectuée sur une conscience, rat effrénée.

Vidéo: Hyperinsulinemic-Euglycemic Clamp in the Conscious Rat

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice

Type 2 diabetes is characterized by a defect in insulin action. The hyperinsulinemic-euglycemic clamp, or insulin clamp, is widely considered the "gold standard" method for assessing insulin action in vivo. During an insulin clamp, hyperinsulinemia is achieved by a constant insulin infusion. Euglycemia is maintained via a concomitant glucose infusion at a variable rate. This variable glucose infusion rate (GIR) is determined by measuring blood glucose at brief intervals throughout the experiment and adjusting the GIR accordingly. The GIR is indicative of whole-body insulin action, as mice with enhanced insulin action require a greater GIR. The insulin clamp can incorporate administration of isotopic 2[14C]deoxyglucose to assess tissue-specific glucose uptake and [3-3H]glucose to assess the ability of insulin to suppress the rate of endogenous glucose appearance (endoRa), a marker of hepatic glucose production, and to stimulate the rate of whole-body glucose disappearance (Rd).
The miniaturization of the insulin clamp for use in genetic mouse models of metabolic disease has led to significant advances in diabetes research. Methods for performing insulin clamps vary between laboratories. It is important to note that the manner in which an insulin clamp is performed can significantly affect the results obtained. We have published a comprehensive assessment of different approaches to performing insulin clamps in conscious mice1 as well as an evaluation of the metabolic response of four commonly used inbred mouse strains using various clamp techniques2. Here we present a protocol for performing insulin clamps on conscious, unrestrained mice developed by the Vanderbilt Mouse Metabolic Phenotyping Center (MMPC; URL: www.mc.vanderbilt.edu/mmpc). This includes a description of the method for implanting catheters used during the insulin clamp. The protocol employed by the Vanderbilt MMPC utilizes a unique two-catheter system3. One catheter is inserted into the jugular vein for infusions. A second catheter is inserted into the carotid artery, which allows for blood sampling without the need to restrain or handle the mouse. This technique provides a significant advantage to the most common method for obtaining blood samples during insulin clamps which is to sample from the severed tip of the tail. Unlike this latter method, sampling from an arterial catheter is not stressful to the mouse1. We also describe methods for using isotopic tracer infusions to assess tissue-specific insulin action. We also provide guidelines for the appropriate presentation of results obtained from insulin clamps.

The hyperinsulinemic-euglycemic clamp, or insulin clamp, is the gold standard for assessing insulin action in vivo. A method for performing insulin clamps in mice is described. This includes a method for arterial catheterization that permits experiments to be performed in conscious, unrestrained mice with minimal stress.

Hyperinsulinémique euglycémique-pinces dans Conscient, Souris illimités

Type 2 diabetes is characterized by a defect in insulin action. The hyperinsulinemic-euglycemic clamp, or insulin clamp, is widely considered the "gold ...

Recherche

Médecine

Angiogenesis in the Ischemic Rat Lung

The adult lung is perfused by both the systemic bronchial artery and the entire venous return flowing through the pulmonary arteries. In most lung pathologies, it is the smaller systemic vasculature that responds to a need for enhanced lung perfusion and shows robust neovascularization. Pulmonary vascular ischemia induced by pulmonary artery obstruction has been shown to result in rapid systemic arterial angiogenesis in man as well as in several animal models. Although the histologic assessment of the time course of bronchial artery proliferation in rats was carefully described by Weibel 1, mechanisms responsible for this organized growth of new vessels are not clear. We provide surgical details of inducing left pulmonary artery ischemia in the rat that leads to bronchial neovascularization. Quantification of the extent of angiogenesis presents an additional challenge due to the presence of the two vascular beds within the lung. Methods to determine functional angiogenesis based on labeled microsphere injections are provided.

The lung is perfused by both the systemic bronchial artery and pulmonary arteries. In most lung pathologies, it is the smaller systemic vasculature that shows robust neovascularization. Cessation of pulmonary blood flow promotes brisk bronchial angiogenesis. We provide surgical details of inducing left pulmonary artery ischemia that promotes bronchial neovascularization.

L&#39;angiogenèse dans le poumon de rat ischémique

The  adult lung is perfused by both the systemic bronchial artery and the entire  venous return flowing through the pulmonary arteries. In most lung ...

Slow-release Drug Delivery through Elvax 40W to the Rat Retina: Implications for the Treatment of Chronic Conditions

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these diseases. Chronic retinal diseases such as retinal oedema or neovascularization usually require multiple intraocular injections to effectively treat the condition. However, the risks associated with these injections increase with repeated delivery of the drug. Therefore, alternative delivery methods need to be established in order to minimize the risks of reinjection. Several other investigations have developed methods to deliver drugs over extended time, through materials capable of releasing chemicals slowly into the eye. In this investigation, we outline the use of Elvax 40W, a copolymer resin, to act as a vehicle for drug delivery to the adult rat retina. The resin is made and loaded with the drug. The drug-resin complex is then implanted into the vitreous cavity, where it will slowly release the drug over time. This method was tested using 2-amino-4-phosphonobutyrate (APB), a glutamate analogue that blocks the light response of the retina. It was demonstrated that the APB was slowly released from the resin, and was able to block the retinal response by 7 days after implantation. This indicates that slow-release drug delivery using this copolymer resin is effective for treating the retina, and could be used therapeutically with further testing.

This paper details how Elvax 40W can be used as a slow-release method for drug delivery to the adult rat retina. The protocol for preparing, loading, and delivering the drug-resin complex to the eye is described.

À libération lente Drug Delivery par Elvax 40W pour le Retina Rat: Implications pour le traitement des maladies chroniques

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these ...

Catheterization of the Carotid Artery and Jugular Vein to Perform Hemodynamic Measures, Infusions and Blood Sampling in a Conscious Rat Model

The success of a small animal model to study critical illness is, in part, dependent on the ability of the model to simulate the human condition. Intra-tracheal inoculation of a known amount of bacteria has been successfully used to reproduce the pathogenesis of pneumonia which then develops into sepsis. Monitoring hemodynamic parameters and providing standard clinical treatment including infusion of antibiotics, fluids and drugs to maintain blood pressure is critical to simulate routine supportive care in this model but to do so requires both arterial and venous vascular access. The video details the surgical technique for implanting carotid artery and common jugular vein catheters in an anesthetized rat. Following a 72 hr recovery period, the animals will be re-anesthetized and connected to a tether and swivel setup attached to the rodent housing which connects the implanted catheters to the hemodynamic monitoring system. This setup allows free movement of the rat during the study while continuously monitoring pressures, infusing fluids and drugs (antibiotics, vasopressors) and performing blood sampling.

Vascular accesses to measure hemodynamics, provide fluids and perform blood sampling are important to any small animal model study. We present a technique for implanting catheters into the carotid artery and the common jugular vein in an anesthetized rat for connecting to a system to perform monitoring, infusions and sampling.

Cathétérisme de l&#39;artère carotide et Veine jugulaire faire pour effectuer des mesures hémodynamiques, Infusions et prélèvement sanguin dans un modèle de rat Conscients

The success of a small animal model to study critical illness is, in part, dependent on the ability of the model to simulate the human condition. ...

Transcutaneous Assessment of Renal Function in Conscious Rodents

Glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional methods to evaluate GFR are cumbersome and time-consuming. In addition, serial blood or urine samples are required, with the associated stress for the experimental animals. A recent technique significantly reduces the investment in time and resources, minimizing the invasiveness and the animal stress, but being equally valid as the traditional approaches. The method measures transcutaneously renal function. Using an optical device and the exogenous renal marker fluorescein isothiocyanate (FITC)-sinistrin, this technique is capable of measuring the elimination kinetics of the marker through the skin. With neither blood nor urine samples nor the associated laboratory assays needed, the results of the transcutaneous measurement are almost instantaneously available. The method has been already validated in different species and successfully applied in several models of renal pathology. Moreover, due to its minimally invasive characteristics, it is suitable for sequential measurements within the same animal. Here is provided a detailed protocol to carry out the transcutaneous assessment of renal function in rodents.

Determination of glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional procedures to measure this parameter are cumbersome and require a large investment of time. Here we describe a faster and minimally invasive method to determinate GFR transcutaneously.

Évaluation transcutanée de la fonction rénale dans Rongeurs Conscious

Glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional methods to evaluate GFR are cumbersome and ...

The Dimethylnitrosamine Induced Liver Fibrosis Model in the Rat

Four to six week old, male Wistar rats were used to produce animal models of liver fibrosis. The process requires four weeks of administration of 10 mg/kg dimethylnitrosamine (DMN), given intraperitoneally for three consecutive days per week. Intraperitoneal injections were performed in the fume hood as DMN is a known hepatoxin and carcinogen. The model has several advantages. Firstly, liver changes can be studied sequentially or at particular stages of interest. Secondly, the stage of liver disease can be monitored by measurement of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes. Thirdly, the severity of liver damage at different stages can be confirmed by sacrifice of animals at designated time points, followed by histological examination of Masson&#39;s Trichome stained liver tissues. After four weeks of DMN dosing, the typical fibrosis score is 5 to 6 on the Ishak scale. The model can be reproduced consistently and has been widely used to assess the efficacy of potential anti-fibrotic agents.

We describe a method to produce an animal model of liver fibrosis in the rat, and assess the degree of fibrosis by histological examination of the liver. The model can be used to study the development of liver disease as well as to test the efficacy of potential anti-fibrotic agents.

Le diméthylnitrosamine Induced Liver Fibrosis Modèle chez le rat

Four to six week old, male Wistar rats were used to produce animal models of liver fibrosis. The process requires four weeks of administration of 10 mg/kg ...

Method of Direct Segmental Intra-hepatic Delivery Using a Rat Liver Hilar Clamp Model

Major hepatic surgery with inflow occlusion, and liver transplantation, necessitate a period of warm ischemia, and a period of reperfusion leading to ischemia/reperfusion (I/R) injury with myriad negative consequences. Potential I/R injury in marginal organs destined for liver transplantation contributes to the current donor shortage secondary to a decreased organ utilization rate. A significant need exists to explore hepatic I/R injury in order to mediate its impact on graft function in transplantation. Rat liver hilar clamp models are used to investigate the impact of different molecules on hepatic I/R injury. Depending on the model, these molecules have been delivered using inhalation, epidural infusion, intraperitoneal injection, intravenous administration or injection into the peripheral superior mesenteric vein. A rat liver hilar clamp model has been developed for use in studying the impact of pharmacologic molecules in ameliorating I/R injury. The described model for rat liver hilar clamp includes direct cannulation of the portal supply to the ischemic hepatic segment via a side branch of the portal vein, allowing for direct segmental hepatic delivery. Our approach is to induce ischemia in the left lateral and median lobes for 60 min, during which time the substance under study is infused. In this case, pegylated-superoxide dismutase (PEG-SOD), a free radical scavenger, is infused directly into the ischemic segment. This series of experiments demonstrates that infusion of PEG-SOD is protective against hepatic I/R injury. Advantages of this approach include direct injection of the molecule into the ischemic segment with consequent decrease in volume of distribution and reduction in systemic side effects.

A unique rat liver hilar clamp model was developed for studying the impact of pharmacologic molecules in ameliorating ischemia-reperfusion injury. This model includes direct cannulation of the portal supply to the ischemic liver segment via a branch of the portal vein, allowing for direct hepatic delivery.

Méthode de Direct segmentaire livraison intra-hépatique L&#39;utilisation d&#39;un modèle hilaire de foie de rat Clamp

Major hepatic surgery with inflow occlusion, and liver transplantation, necessitate a period of warm ischemia, and a period of reperfusion leading to ...

Assessment of Respiratory Function in Conscious Mice by Double-chamber Plethysmography

Air volume changes created by a conscious subject breathing spontaneously within a body box are at the basis of plethysmography, a technique used to non-invasively assess some features of the respiratory function in humans as well as in laboratory animals. The present article focuses on the application of the double-chamber plethysmography (DCP) in small animals. It provides background information on the methodology as well as a detailed step-by-step procedure to successfully assess respiratory function in conscious, spontaneously breathing animals in a non-invasive manner. The DCP can be used to monitor the respiratory function of multiple animals in parallel, as well as to identify changes induced by aerosolized substances over a chosen time period and in a repeated manner. Experiments on control and allergic mice are used herein to demonstrate the utility of the technique, explain the associated outcome parameters, as well as to discuss the related advantages and shortcomings. Overall, the DCP provides valid and theoretically sound readouts that can be trusted to evaluate the respiratory function of conscious small animals both at baseline and after challenges with aerosolized substances.

The objective of the present article is to provide a detailed description of the recommended procedures to evaluate respiratory function in conscious mice by double-chamber plethysmography.

Évaluation de la fonction respiratoire chez des souris conscientes par pléthysmographie Double-chambre

Air volume changes created by a conscious subject breathing spontaneously within a body box are at the basis of plethysmography, a technique used to ...

Multi-system Monitoring for Identification of Seizures, Arrhythmias and Apnea in Conscious Restrained Rabbits

Patients with ion channelopathies are at a high risk of developing seizures and fatal cardiac arrhythmias. There is a higher prevalence of heart disease and arrhythmias in people with epilepsy (i.e., epileptic heart.) Additionally, cardiac and autonomic disturbances have been reported surrounding seizures. 1:1,000 epilepsy patients/year die of sudden unexpected death in epilepsy (SUDEP). The mechanisms for SUDEP remain incompletely understood. Electroencephalograms (EEG) and electrocardiograms (ECG) are two techniques routinely used in the clinical setting to detect and study the substrates/triggers for seizures and arrhythmias. While many studies and descriptions of this methodology are in rodents, their cardiac electrical activity differs significantly from humans. This article provides a description of a non-invasive method for recording simultaneous video-EEG-ECG-oximetry-capnography in conscious rabbits. As cardiac electrical function is similar in rabbits and humans, rabbits provide an excellent model of translational diagnostic and therapeutic studies. In addition to outlining the methodology for data acquisition, we discuss the analytical approaches for examining neuro-cardiac electrical function and pathology in rabbits. This includes arrhythmia detection, spectral analysis of EEG and a seizure scale developed for restrained rabbits.

Using simultaneous video-EEG-ECG-oximetry-capnography, we developed a methodology to evaluate the susceptibility of rabbit models to develop provoked arrhythmias and seizures. This novel recording system establishes a platform to test the efficacy and safety of therapeutics and can capture the complex cascade of multi-system events that culminate in sudden death.

Surveillance multi-systèmes pour l’identification des crises, des arythmies et de l’apnée chez les lapins retenus conscients

Patients with ion channelopathies are at a high risk of developing seizures and fatal cardiac arrhythmias. There is a higher prevalence of heart disease ...

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.

Prélèvement sanguin répétitif dans la veine sous-clavière d’un rat conscient

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 ...