ВПЛИВ ЕНДОГЕННИХ ПРОСТАНОЇДІВ НА ЖОВЧОСЕКРЕТОРНУ ФУНКЦІЮ У ЩУРІВ РІЗНИХ ВІКОВИХ ГРУП

Abstract

In acute experiments on different age group of 30 white wild-type rats: juvenile (weight 130–175 g), mature (weight 200–250 g) and old (weight 300 g and more) we were investigated the changes in the volume rate of bile secretion with cyclooxygenase inhibition by acetylsalicylic acid (100 mkg/kg weight of animal) which is a blocker of the prostaglandin synthesis enzyme. We explored the changes of the level of choleresis and bile biochemical components by thin-layer chromatography In vivo. The relative abundances of cholecycle, henodeoxycholic, taurocholic and glycocholic bile acids in the liver of rats were determined by chromatography, with the subsequent densitometry. The biliary acid flow rate was calculated as the sum of the bile acid concentration multiplied by the volume of secreted biliary in one relevant thirty-minute sample. The conjugation coefficients were calculated for each thirty minute sample. Reduction of bile secretion by endogenous prostanoids was shown, because inhibition of prostaglandins synthesis caused the hypercholeresis on 42–112,5 % in different rat age groups, compared to control. Endogenous prostaglandins suppressed the processes of conjugation in old and juvenile age group on 117–189,1 %, in contrast these regulators have no significant effect on bile acids association with glycine and taurine in mature rats. The binding of endogenous prostanoids probably increased the conjugation processes in juvenile rats, whereas in the old experimental group acetylsalicylic acid was significantly reduced by 123 % on average. Analysis of changes in free and conjugated bile acids in the rats of different age groups showed that the ratio of qualitative changes in structure of the liver bile in rats with the cyclooxygenase blockade is mainly due to enhanced synthesis of free bile acids de novo. Therefore, endogenous prostanoids affect in the opposite way. There are have multi-directional impact on bile secretion in different age groups of rat that means ambiguous role of these drugs in liver function regulation at different stages of ontogenesis.