Cardiac Response to Hepatic Ischemia-Reperfusion: Effect of Exercise and Oxytocin Compared to L-arginine

Abstract

The present work was designed to investigate the possible hepatic and cardiac functional and structural changes, as well as the cardiac responses to its in vitro ischemia-reperfusion injury (IR) in a rat model of hepatic IR injury. Also, to evaluate the potential effect and mechanism(s) of exercise training and oxytocin, either each alone or together, in comparison to, L-arginine, the nitric oxide donor, in protecting the liver and heart function and structure against the assumed liver IR-induced impairment. The study was carried out on 62 adult male albino rats, which were allocated into the following 6 groups: Group I: Sham-Operated Control group (Sham group) (n=10): Rats in this group were kept undisturbed in their cages for 3 weeks. In the fourth week, rats received 2 ml/kg distilled water (L-Arg solvent) daily, by oral gavage. At the end of the fourth week, rats were subjected to the same surgical procedures as hepatic IR group without portal triad clamping, then were studied after 2 hours. Group II: Hepatic ischemia-reperfusion group (IR group) (n=10): Rats in this group were kept undisturbed in their cages for 3 weeks. In the fourth week, rats received distilled water as sham-operated group. At the end of the fourth week, rats underwent hepatic IR (30 minutes of partial hepatic ischemia (70%) followed by 2 hours of reperfusion), then studied. Group III: L-arginine-treated hepatic ischemia-reperfusion group (L-Arg + IR group) (n=10): Rats in this group were kept undisturbed in their cages for 3 weeks. In the fourth week, rats received L-Arg daily, in a dose of 100 mg/kg by oral gavage. At the end of the fourth week, rats underwent hepatic IR, then were studied. Group IV: Exercise-trained hepatic ischemia-reperfusion group (Ex + IR group) (n=10): Rats in this group were subjected to swim exercise 2 hours daily, 6 days/week for 4 weeks. In the fourth week, rats, received distilled water as in sham-operated group. At the end of the fourth week, rats underwent hepatic IR, then were studied.