Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat

Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat

Bibliographic Details
Main Author: Sutayatram, Saikaew, DVM
Language:English
Published: The Ohio State University / OhioLINK 2014
Subjects:
Physiology
Pharmacology
Exercise
Clenbuterol
Carvedilol
Dobutamine
Imipramine
Heart failure
ECG
cardiac function
rat
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=osu1417521358
id ndltd-OhioLink-oai-etd.ohiolink.edu-osu1417521358
record_format oai_dc
collection NDLTD
language English
sources NDLTD
topic Physiology
Pharmacology
Exercise
Clenbuterol
Carvedilol
Dobutamine
Imipramine
Heart failure
ECG
cardiac function
rat
spellingShingle Physiology
Pharmacology
Exercise
Clenbuterol
Carvedilol
Dobutamine
Imipramine
Heart failure
ECG
cardiac function
rat
Sutayatram, Saikaew, DVM
Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat
author Sutayatram, Saikaew, DVM
author_facet Sutayatram, Saikaew, DVM
author_sort Sutayatram, Saikaew, DVM
title Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat
title_short Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat
title_full Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat
title_fullStr Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat
title_full_unstemmed Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat
title_sort effects of exercise, clenbuterol, carvedilol, dobutamine, and sedentary existence in acute imipramine-induced heart failure in rat
publisher The Ohio State University / OhioLINK
publishDate 2014
url http://rave.ohiolink.edu/etdc/view?acc_num=osu1417521358
work_keys_str_mv AT sutayatramsaikaewdvm effectsofexerciseclenbuterolcarvediloldobutamineandsedentaryexistenceinacuteimipramineinducedheartfailureinrat
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-osu14175213582021-08-03T06:28:23Z Effects of Exercise, Clenbuterol, Carvedilol, Dobutamine, and Sedentary Existence in Acute Imipramine-Induced Heart Failure in Rat Sutayatram, Saikaew, DVM Physiology Pharmacology Exercise Clenbuterol Carvedilol Dobutamine Imipramine Heart failure ECG cardiac function rat Goal: Primary goal of this study was to determine if exercise training or exposure to drugs would protect rats from acute and reversible heart failure produced by IV imipramine.Methods: Fifty-four, male, Sprague-Dawley rats were allocated randomly into 5 intervention groups (n = 10): (1) sedentary, (2) exercise, (3) carvedilol, (4) clenbuterol, and (5) dobutamine. Six rats in each intervention received imipramine challenge. A 6th group (n = 4) was sedentary but received a matched-volume vehicle challenge. The variables studied were: orthogonal lead ECGs, systemic arterial and left ventricular pressures, maximal rates of rise and fall of left ventricular pressure, left ventricular end-diastolic and end-systolic volumes, body weight, and weights of brain, heart, and adrenal. Values were expressed as means ± SE. ECGs were obtained (1) after rats had received interventions and while anesthetized with pentobarbital (baseline pre-surgery), then ECGs and hemodynamics were recorded (2) before they received imipramine or vehicle infusion (baseline instrumentation), (3) at the mid-point of infusion (mid-dose), (4) at the end-point of infusion (end-dose), and (5) 1 hour after cessation of infusion (end recovery). Differences of statistical significance in means for all parameters measured during imipramine challenge were assessed among groups and times using 2-way ANOVA with repeated measures.Results and Discussion: Exercise, carvedilol, clenbuterol, and dobutamine produced physiological effects consistent with their known properties. All rats survived imipramine challenges with hemodynamic and ECG changes typical of acute imipramine exposure, i.e., an initial decrease in function with or without spontaneous recovery during infusion, and then recovery nearly complete within 1 hour after cessation of infusion. No intervention altered statistically (i.e., blunted or exaggerated) the hemodynamic responses to imipramine; however differences among interventions were noted. All interventions, except carvedilol, lengthened QA. Such lengthening could be caused by: (1) reduction in myocardial contractility, (2) decreased elasticity modulus of the aorta, and (3) prolongation of QRS and/or electromechanical coupling. The lack of protection of against the hemodynamic effects of imipramine, mimicking a failing heart, may be due to: (1) inability to measure differences, (2) the interventions are truly ineffective, and (3) imipramine-induced dysfunction differs from naturally occurring failing heart.On the other hand, significant differences between interventions were noted in the ECG response to imipramine. Prolongations of the QT, QTc, and T wave durations triggered by imipramine were blunted equally by exercise and carvedilol when compared with dobutamine. Dobutamine produced the greatest change in QT in response to imipramine compared to all other groups, and the greatest changes of QTc and T duration compared with those of exercise and carvedilol. Clenbuterol trended to further prolong PR interval.Imipramine decreased the height of the R wave in all groups. However, R wave amplitude in lead AVF remained depressed after cessation of imipramine longer for clenbuterol than for other interventions; no other significant differences among interventions during recovery were noted.Conclusion: Neither exercise nor pharmacological training abolished the negative hemodynamic effects of imipramine. However, both exercise and carvedilol treatments blunted the electrocardiographic effects of imipramine. 2014 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1417521358 http://rave.ohiolink.edu/etdc/view?acc_num=osu1417521358 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

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