Bile acids exhibit detergent properties. Their influence on various types of cells in the gastrointestinal wall, including smooth muscle cell, is substantial. They are present in the intestinal lumen and circulation as conjugated or deconjugated salts. In studies in vitro they cause smooth muscle relaxations. Their effects in vivo can be due to their direct action on the smooth muscles or they act indirectly: the action can be mediated by the nervous system and gut hormone release. When the gastrointestinal mucosa is exposed to bile or bile acids the frequency of gastric contractions increases and the activity front of the migrating motor complex (MMC) is initiated. Bile acids exert a stronger effect than the entire bile. The type and amount of bile acids can also be important. The intraarterial route of bile acid administration appears to be more efficient than intraluminal route. Bile diversion from the duodenum induces contrary effects, i.e. a relaxing effect in the stomach and irregular motor activity in the small bowel or prolonged phase 2 MMC have been observed. These effects are apparently due to the interaction of bile acids with muscarinic receptors and mediated by motilin and cholecystokinin, two gut hormones the release of which is strongly influenced by luminal bile acids.
On the basis of the literature the results of experimental investigations on hypocholesterolemic action of saponins are demonstrated. Also the theories explaining the mechanism of this action are discussed.
PL
Na podstawie piśmiennictwa omówiono wyniki eksperymentalnych badań dotyczących hypocholesterolemicznego działania saponin. Ponadto przedstawiono teorie sugerujące możliwe mechanizmy takiego działania, m.in. wskutek tworzenia kompleksów saponin z cholesterolem, a także zwiększonego wydzielania kwasów żółciowych, kosztem biosyntezy cholesterolu.
The aim of this study was a comparison of results of the bile acids test and antipyrine test on calves. The experiment was carried out on 10 healthy calves of Black and White breed. In each subject the antipyrine test was performed on day 10 and 20 after birth. The concentration of bile acids in plasma before feeding (fasting - f SKŻ) and 2 hours after feeding (p SKŻ) were also determined. A correlation analysis was used to compare results of the bile acids test with the antipyrine test. The obtained results indicated that the hepatic biotransformation rate of antipyrine in calves increased significantly with age. The concentrations of fasting bile acids in the plasma of 10 day-old calves and 20 day-old calves were not significantly different. Similar results were obtained in the case of postfeeding bile acids concentrations. In contrast, the concentration of bile acids in plasma 2 hours after feeding was significantly (P<0.01) higher (both in 10 day-old and 20 day-old calves) than the concentration of fasting bile acids. It was determined that fasting and postfeeding concentrations of bile acids in plasma and values of metabolic clearance of antipyrine (C1A) were significantly (P<0.01) correlated.