1,721,257 research outputs found
Biliary lipid secretion and gallbladder motor function in man, and effects of ursodeoxycholic acid
No full textABSTRACT
The two main aims of the studies reported in this thesis were 1)
to obtain a detailed description of gallbladder motor function in
man; and 2) to clarify the mechanism whereby ursodeoxycholic acid
(UDCA) reduces cholesterol saturation of bile.
In order to achieve these aims, seven gallstone subjects were
studied. Repeat studies were carried out in six patients during
treatment with UDCA, and the methodology was validated in these
subjects and in two cholecystectomized patients. A conventional
intestinal perfusion technique was used to measure secretory
outputs into the duodenum. This was combined with a continuous
intravenous infusion of indocyanine green as a hepatic bile
marker to derive hepatic secretion rates, and with an intravenous
bolus of 99mTC RIDA as a gallbladder bile marker to derive
quantitative measurements of absolute gallbladder filling and
emptying. Subjects were studied aver a thirteen hour period that
included an evening meal followed by an overnight fasto
The studies of gallbladder motor function suggested that the
canventional concept of the gallbladder as a simple pump that
empties postprandially and fills during fasting requires
modification. Postprandially, filling always accompanied
predominant emptying, and during fasting emptying often
accompanied predominant filling. In both phases, the majority of
the hepatic bile entered the gallbladder before reaching the
duadenum. These findings suggest that gallbladder motor function
is more analogous to a "bellows" than to a simple pump, and this
may be important in mixing of gallbladder contents.
The effect of UDCA on cholesterol saturation of hepatic bile was
due to an alteration in bile acid secretory coupling with
phospholipid in addition to cholesterol. An additional effect of
UDCA, if administered at bedtime, was to maintain hepatic bile
acid secretion rate during overnight fasting, thus preventing the
nocturnal secretion of supersaturated hepatic bile that occurs at
low bile acid secretion rates. The effect of UDCA on cholesterol
saturation of fasting gallbladder bile was due to an increase in
the total mass of bile acid stored in the gallbladder, without
any effect on cholesterol masso UDCA was also shown to inhibit
gallbladder emptying and pancreatic enzyme secretion postprandially
Review article: The mechanical pumps of the enterohepatic circulation of bile acids - defects in celiac disease
No full text
- …
