Inroduction. Previously, it has been demonstrated on rats that 20 week high-energy diet (HED) leads to the development of metabolic syndrome (MS) in the course of which the hepatic steatosis was observed. Taking into consideration the fact that the main function of bile acids (BA) is digestion and lipid absorption, the regulation of the cholesterol synthesis as well as the bile formation and secretion, the purpose of the article is to investigate the spectrum of cholates in BA in the bile of rats with MS. Materials and methods. The research was conducted on female rats with initial weight of 210-215 grams. During the first week of the research all rats received the standard food and water ad libitum. During the 2nd week the rats were divided into two groups at random: І – received the standard food and water ad libitum (the control group), II – was on HED (diet No. 11024, Research Diets, New Brunswick, NJ). Within 20 weeks the common bile duct was cannulated under urethane anesthesia (1g/kg of the body weight). During 3 hours of the observation the bile samples were selected every 30 min. Using thin layer chromatography and densitometer DО-1M every sample of the bile was examined for the concentration of separate free or conjugated bile acids. On "Silufol" plates the bile acids were distributed as follows: taurocholic acid (TCA), the mixture of taurochenodeoxycholic and taurodeoxycholic acids (TCDCA+TDCA), glycocholic acid (GCA), the mixture of glycochenodeoxycholic and glycodeoxycholic acids (GCDA+GDCA), cholic acid (CA), the mixture of chenodeoxycholic and deoxycholic acids (CDA+DA). Results. During the three-hour testing the concentration of TCA in rats’ bile with MS increased in all 30-minute samples. In the 1st sample, the TCA concentration increase comprised 10.2% (p < 0.05), in the 6th sample – 15.3% (p < 0.05). Moreover, the overall level of TCDCA+TDCA was higher and increased by 30.3% (p < 0.05) in the 1st sample and by 36.3% (p < 0.05) in the 6th sample. Unlike tauroconjugated BA, the concentration of glycoconjugated BA in rats’ bile with MS was changing in different directions. The concentration of GCA decreased by 35.3–43.9 % (p < 0.05) and the level of glycochenodeoxycholic GCDA+GDCA in all samples increased by 34.8–41.6 % (p < 0.05). The concentration of CA in the rats’ bile with MS did not change significantly, thus the overall level of the free BA CDA+DA remained higher during the whole process of testing. The highest increase was in the second sample and made 35.5 % (p < 0.05) as compared with the control group. Conclusions. Thus, the long staying of rats on a high-calorie diet resulted in the development of steatohepatosis, the increase of choleresis and significant changes in the composition of the bile of rats. Thus, under the conditions of MS development, the processes of trihydroxycholestenoic initial bile acid conjugation in hepatocytes were stimulated – cholic acid with taurine, while the processes of cholic acid conjugation with glycine were suppressed. The observed increase of TCA concentration in the rats’ bile with MS may indicate the activation of intracellular enzymes which provide the conjugation of BA with taurine and is the result of the intensification of taurocholate transportation through hepatocytes cell membrane. In this case the conjugation coefficient was not changed and the hydroxylation coefficient decreased which indicates the activation of the alternative pathway of biosynthesis of bile acids.
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