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Biomedical subjects

W H Admirand

Publications and source records attributed to W H Admirand.

17 recordsLinked to original sources
PubMed1981

Effect of chronic changes in rate of enterohepatic cycling on bile acid kinetics and biliary lipid composition in the rhesus monkey.

Although several studies have demonstrated an inverse relationship between size of the bile salt pool and frequency of enterohepatic cycling, most such data have been obtained in conditions where control of cycling frequency was not possible. In this study, we diverted bile from the bile duct of Rhesus monkeys into a reservoir and returned it to the duodenum at varying rates, a model that mimicked differences in frequency of gallbladder emptying. As cycling frequency increased from 1 to 8 cycles/day, size of the bile salt pool decreased from 1756 microM to 369 microM. Changes in fractional turnover rate parallelled changes in cycling frequency. The relative composition of the biliary lipids remained the same throughout the range of cycling frequencies. These data show that direct manipulation of cycling frequency had the predicted effects on other parameters of the enterohepatic circulation but did not give rise to lithogenic bile.

Animals↗
PubMed1978

Effects of cholecystectomy upon bile salt kinetics in the guinea pig.

The effects of cholecystectomy upon bile salt kinetics were studied in normal guinea pigs. After cholecystectomy, bile salt pool size decreased, fractional daily turnover rate increased, and the rate of bile salt synthesis was unchanged. These data indicate that an increased frequency of bile salt enterohepatic cycling is sufficient to produce alterations in bile salt kinetics. Abnormalities of bile salt synthesis need not be present in order for a reduction in pool size to occur.

Animals↗
PubMed1977

Enzymatic sulfation of bile salts. Partial purification and characterization of an enzyme from rat liver that catalyzes the sulfation of bile salts.

An enzyme system which catalyzes the transfer of sulfate group from 3'-phosphoadenosine-5'-phosphosulfate to bile salts has been identified and characterized from rat liver. The enzyme is present in the cytosol fraction of liver cells. The apparent Km value for 3'-phosphoadenosine-5'-phosphosulfate was 8 - 10(-6) M andhat for taurolithocholate was 5 - 10(-5) M. Sulfation occurred with conjugated as well as unconjugated bile salts, however, the rate of sulfation was higher with conjugated than unconjugated. The enzyme was present in rat liver and kidney, but not detectable in brain, lung, heart, spleen or intestinal mucosa. The activity is completely inhibited by p-chloromercuribenzoate indicating the enzyme requires a sulfhydryl group for activity. A molecular weight of 130 000 was estimated by gel-filtration technique and the enzyme shows an isoelectric point of 5.3.

Animals↗
PubMed1977

Hyperoxaluria correlates with fat malabsorption in patients with sprue.

The effect of fat malabsorption on the absorption and renal excretion of dietary oxalate was studied in four patients with sprue and in two patients with dermatitis herpetiformis and sprue-like jejunal histology. Hyperoxaluria was present in all patients with sprue when fat malabsorption was severe. Urinary oxalate excretion decreased in two of the three patients with coeliac sprue when their fat malabsorption had improved after three months of dietary gluten restriction. Neither patient with dermatitis herpetiformis and sprue had steatorrhoea. In these patients, urinary oxalate excretion was always within normal limits. A significant positive linear relationship (y=28.25 +4-84x; r=0-82; P less than 0-01) was demonstrated between faecal fat and urinary oxalate excretion. The results of this study support the concept that severe malabsorption of dietary fat plays a primary causative role in enteric hyperoxaluria.

Calcium↗
PubMed1968

The physicochemical basis of cholesterol gallstone formation in man.

The concentrations of bile salt, lecithin, and cholesterol were determined on each of 66 samples of gall bladder bile from patients with cholesterol gallstones and 25 samples of normal gall bladder bile. When these three constituents were plotted simultaneously on triangular coordinates, a complete separation of the normal and "abnormal" bile was achieved. This separation was the result of an increase in the quantity of cholesterol relative to the amounts of bile salts and lecithin contained in the bile from patients with cholesterol gallstones. An in vitro model system was constructed (on triangular coordinates) that allows prediction of the maximum amount of cholesterol that can be solubilized in solutions containing varying proportions of bile salt and lecithin. When the bile data were compared with the solubility of cholesterol derived from the model system, normal biles were found to be less than saturated with cholesterol, whereas biles from patients with cholesterol gallstones were saturated and in some cases contained insoluble cholesterol in the form of microcrystals. It is suggested that the physical state of bile (i.e., the presence or absence of insoluble cholesterol) is determined by the relative concentrations of bile salt, lecithin, and cholesterol, and the other biliary constituents do not appear to significantly effect the solubility of cholesterol in bile.

Bile↗