Effects of russell's viper venom on renal functions in splenectomized dogs

Abstract

This investigation was performed to study the effects of Russell's viper venom on renal functions in splenectomized dogs and the dogs pretreated with indomethacin. Twenty anesthetized dogs weighed 10-15 kgs. were used and devided into four groups. The studies were carried out in normal animals as control (Group I), in splenectomized dogs by 10 days postsplenectomy (Group II), in animals pretreated with indomethacin (Group III) and splenectomized dogs pretreated with indomethacin (Group IV). Animals in group III and group IV were fed indomethacin 100 mg daily for 3 days prior to the experiment. Four groups of five animals received 0.1 mg/kg.bw. of Russell's viper venom by intravenous injection. General circulation and renal functions were measured before venom injection and observed for period of 3 hours after venom injection. The animals in group I and group II without pretreated with indomethacin produced a marked reduction in mean arterial blood pressure (MAP) and recovered to control level in a long period as compared to group III and group IV which pretrea-ted with indomethacin. It should be noted that heart rate (HR) after envenomation were variable response in all of animals. The increment in packed cell volume (PCV) was observed in intact animals, whereas it did not occur in splenectomized animals after envenomation. Cardiac output (CO), plasma volume (PV) and blood volume (BV) decreased in the same pattern and did not show a significant different when compared between pretreated and non pretreated animals with indomethacin. The percentage of increment in total peripheral resistance (TPR) after venom injection was dominated in animals pretreated with indomethacin, while the renal vascular resistance (RVR) was markedly increased in non pretreated animals more than pretreated animals. Renal plasma flow (RPF), renal blood flow (RBF) and glomerular filtration rate (GFR) decreased markedly in control animals (group I) as compared with the other groups, Similar increases in filtration fraction (FF) was observed. Renal fraction (RF) of cardiac output in indomethacin pretreated animals was increased, whereas it decreased in non pretreated animals after envenomation. Urinary excretion and fractional excretion of sodium. chloride and urinary osmolar excretion decreased in all groups of animals after envenomation and slightly increase in fractional excretion of potassium was recorded. All animals given the venom showed decrease in osmolar clearance while free water clearance increase. These results may conclude that Russell's viper venom causes direct effect to produce hypotension due to decrease renal functions. The mechanism of the action appears to be mediated by prostaglandin synthesis. The effect of Russell's viper venom on pathophysiology of kidney whether intact or splenectomized animals are not different.