Bile Secretion In Rats Research Articles

Effect of cyclosporine on bile secretion in rats

Short-term effects of cyclosporine were studied in the isolated perfused rat liver model. Bile flow was inhibited by cyclosporine in 2 mg/kg and 20 mg/kg doses but not by a 0.2 mg/kg dose. Cholestasis was accompanied by a decrease in bile acid secretion, indicating an inhibitory effect on the bile acid-dependent fraction of bile flow. Perfusate bilirubin levels increased threefold in rat livers given 20 mg/kg of cyclosporine, but did not change in control animals. Alkaline phosphatase and transaminase levels did not differ from those of control animals. The isolated perfused rat liver was able to excrete cyclosporine, as demonstrated by a continual decrease in perfusate cyclosporine levels. No light microscopic evidence of cholestasis or hepatocellular damage was demonstrated on histologic staining. Our model appears to be a good one for the study of altered hepatic physiologic characteristics caused by administration of cyclosporine.

Cholagogic effect of ginger and its active constituents

The effect of bile secretion in rats was examined in order to clarify the stomachic action of ginger and also to investigate its active constituents. The results showed that mainly the acetone extracts of ginger, which contain essential oils and pungent principles, caused an increase in the bile secretion. Further analyses for the active constituents of the acetone extracts through column chromatography indicated that [6]-gingerol and [10]-gingerol, which are the pungent principles, are mainly responsible for the cholagogic effect of ginger.

Dynamics of bile secretion in rats after sialadenectomy

Dynamics of bile secretion in rats after sialadenectomy

Effects of clofibrate, cholestyramine, zanchol, probucol, and AOMA feeding on hepatic and intestinal cholesterol metabolism and on biliary lipid secretion in the rat.

Utilizing newer techniques for measuring rates of cholesterol synthesis, the effects of clofibrate, cholestyramine, zanchol, probucol, and AOMA (a copolymer of maleic acid and an alpha-olefin chain of 18 carbons) on hepatic and intestinal cholesterol metabolism and on biliary lipid secretion in the rat were examined. Uncer conditions of isocaloric feeding, female rats were administered a fixed amount of these drugs each day for 14 days. In one set of experiments the rats were killed and rates of hepatic and intestinal cholesterol synthesis and tissue cholesterol levels were measured. In a second set of studies the rats were subjected to total biliary diversion for 2 hr and rates of biliary lipid secretion were determined. Plasma cholesterol concentrations were measured in all animals. Neither AOMA nor cholestyramine had any effect on plasma cholesterol levels or biliary lipid secretion, but both markedly enhanced intestinal cholesterol synthesis. Cholestyramine also increased hepatic cholesterol synthesis. Clofibrate significantly decreased plasma cholesterol levels, whereas zanchol had the opposite effect. Both clofibrate and zanchol increased liver size and bile secretion rates but lowered biliary lipid concentrations; however, total biliary lipid output was unchanged. Total hepatic cholesterol synthesis in clofibrate-fed animals was similar to that in the controls, but in zanchol-fed animals it was approximately doubled. Neither clofibrate nor zanchol had any effect on intestinal cholesterol synthesis. Probucol dramatically lowered plasma cholesterol levels but had no effect on the other parameters measured. None of the drugs was effective in altering the molar percentage of cholesterol in bile despite the diversity of metabolic changes which occurred. These studies point up the many diverse metabolic effects of these drugs, some of which are clinically useful in lowering plasma cholesterol levels, and delineate the marked dissociations that occur between rates of cholesterol synthesis, tissue cholesterol levels, and plasma cholesterol concentrations.

Pharmacological studies of Gardeniae fructus. II. Contribution of the constituent crude drugs to choleretic activity of "Inchinko-to" in rats (author's transl)

Pharmacological examination was made on bile secretion in rats of "Inchinkoto" ( ?? 〓 ?? ?? ), the most representative preparation for jaundice in Chinese medicine, and on each of its three constituent crude drugs (Gardeniae Fructus, Artemisiae Capillaris and Rhei Rhizoma). The extract of Gardeniae Fructus hardly increased bile secretion, while genipin, an agiycone of geniposide which is present in this crude drug, markedly increased it. Essential oils from Artemisiae Capillaris (Spica) and its oil-free extract increased bile secretion and 6, 7-dimethylaesculetin, which is one of the components of this crude drug, also showed the same effect. On the contrary, the extract of Rhei Rhizoma was not effective in this test. The extract prepared from "Inchinko-to" increased bile secretion and its action seemed to depend highly on that induced by Artemisiae Capillaris (Spica). The combination of genipin and 6, 7-dimethyl-aesculetin synergistically increased bile secretion.

Gastro-intestinal hormones and bile secretion in the perfused pig liver: the effects of secretin, cholecystokinin and pentagastrin.

The effects of secretin, cholecystokinin and pentagastrin on the hepatic bile secretion rate were studied in the perfused pig liver. An increase in the bile secretion rate and bicarbonate output was found during secretin infusion. Simultaneous infusion of either cholecystokinin or pentagastrin with secertin augmented this increase to level greater than the sum of the single hormone responses. Secretin produced a fall in bile‐salt output. but neither cholecystokinin nor pentagastrin had any such effect. However, when either cholecystokinin or pentagastrin was infused together with secretin, there was an increase in bile salt output for 30 minutes, followed by maintenance of output at base‐line values. All three hormones must therefore influence the handling of bile salts by the hepatocyte.

Fluoride secretion in rat bile.

The rate of bile secretion in fasted male rats and corresponding bile and plasma fluoride concentrations were studied to determine if significant quantities of fluoride are secreted into the small intestine from the bile duct during fluoride absorption. The osmolalities and fluoride levels were similar to those of plasma ; this suggests that the rat biliary system does not concentrate fluoride.

Changes in bile secretion produced by hippocampal and hypothalamic stimulation

The influence of conditioning electrical stimuli applied to the anterior hypothalamus or hippocampus on the effect exerted by the posterior hypothalamus on bile secretion was studied in anesthetized cats. Electrical stimulation of the posterior hypothalamus alone caused a significant increase in flow from the isolated common bile duct during 4 hours. A significant increase in average potassium concentration was found in bile samples collected during this period. Electrical stimuli applied to the anterior hypothalamus or dorsal hippocampus prior to the posterior hypothalamic stimulation.abolished the expected increase in bile flow and potassium concentration. The present experiments indicate that interactions within the hypothalamo-hippocampal system may affect the rate of bile secretion and its electrolyte composition. It seems that there exists a central nervous system regulation modifying potassium efflux.

Bile flow in adrenalectomized rats.

ABSTRACT The effect of adrenalectomy on the bile secretion in rats was studied. The bile was collected by cannulation from the choledochus. The bile output of the adrenalectomized animals was significantly decreased, being about a half that of the control rats. No difference was found in bile secretion of the control animals and the rats which had undergone exposure of the adrenal glands only.

ON THE EXPULSION OF BILE BY THE GALL BLADDER; AND A RECIPROCAL RELATIONSHIP WITH THE SPHINCTER ACTIVITY

After feeding a dog, forceful contractions of the gall bladder occur that are sufficient in strength to expel part of the contents of the viscus against a considerable pressure resistance. The pressure within the gall bladder of a healthy, unanesthetized dog fasted 24 to 48 hours is usually about equal to a column of bile 100 mm. high. After a few swallows of food there is a rapid increase in the pressure to more than 200 mm. with a gradual fall in it again, and repeated similar rises and falls occur thereafter. The gall bladder contractions responsible for these alterations are accompanied by a lessening in the resistance to the passage of bile to the intestine, a resistance which is maintained by the muscles at the lower end of the common duct. There would appear to be a reciprocal response on the part of the two structures to the one stimulus. The maximum pressure developing within the temporarily obstructed biliary tract in an animal with the gall bladder excluded about equals that of a column of bile slightly more than 300 mm. in height. The taking of food acts as a stimulus on the rate of bile secretion, but does not alter the maximum secretion pressure. When the gall bladder is connected with the duct system, obstruction does not lead until after some hours to the development of a pressure of more than 100 to 150 mm. within the biliary tract,-that is to say the pressure does not rise above the normal. Its failure to rise further is referable to the activity of the gall bladder to store and concentrate the bile as secreted. The physiological and clinical significance of these findings is discussed.