Biomedical subjects
Publications and source records attributed to G Paumgartner.
It could be demonstrated that intraportal infusion of prostaglandin A1 (1 mug/min/100 g body wt.) in Wistar rats significantly increases bile flow. An analysis of the relationship between bile salt excretion and bile flow revealed that this choleresis is due to an increase in the bile salt independent fraction of bile.
The concentrations of bile acids in serum determined by a relatively simple enzymatic method ranged between 1.6 and 9.2 mumol/l in 60 normal volunteers and between 2.1 and 7.7. mumol/l in 14 patients with Gilbert's syndrome. In contrast, 48 patients with various liver diseases had - with 2 exceptions - markedly elevated serum bile acids (up to 140 mumol/l). Together with BSP retention, BSP disappearance and SGOT, the bile acid level in serum represented one of the most sensitive indices for detection of liver disease. The sensitivity of this test can be further increased by bile acid determination 2 h after a meal. Since this test is both simple and harmless its broader clinical use appears attractive.
Both chenodeoxycholic acid, in the dosage administered for dissolution of gallstones, and cholic acid are completely conjugated during one passage through the liver. The glycine:taurine ratio increases with the cumulative amount of exogenous bile acids secreted, which suggests consumption of available taurine. Since conjugation with glycine compensates for deficiency of the taurine conjugating system, it can be assumed that in the normal liver and with doses not exceeding 2.5 mmoles, chenodeoxycholic acid is efficiently and completely transformed into its "physiologic" conjugated form.
Explore the source record for details and available documents.
The effects of pretreatment for 4 days with the hepatic microsomal enzyme inducers phenobarbital (8 mg/100 g body weight), spironolactone (20 mg/100 g body weight) and pregnenolone-16alpha-carbonitrile (7 mg/100 g body weight) on bile flow and bile pipid secretion have been compared in rats. Similar to phenobarbital, spironolactone and pregnenolone-16alph-carbonitrile increased bile flow but did not alter bile salt excretion, indicating that these agents increased bile salt independent bile formation. This finding could be substantiated for spironolactone by studies of the relationship between bile salt excretion and bile flow during bile salt infusions. Whereas phenobarbital decreased cholesterol and phospholipid secretion to 39 and 49 per cent, respectively, spironolactone and pregnenolone-16alpha-carbonitrile more than doubled cholesterol excretion without influencing phospholipid output. As a consequence, marked differences in the effect on cholesterol saturation were observed: a decrease by phenobarbital and an increase following spironolactone and pregnenolone-16alpha-carbonitrile. The present studies demonstrate that different types of enzyme inducers may share certain effects on bile formation and differ in others.
The uptake of taurocholate (TC) by the perfused rat liver was studied by the multiple indicator dilution technique using single injections of 14-C-labeled TC and 99m-Tc-labeled albumin. For determination of the intra- and extravascular space, 51-Cr-labeled erythrocytes and albumin were used. TC was found to be distributed into an extravascular space equivalent to that of albumin. Analysis of the dilution curves, according to Goresky (Am J Physiol 207:13-26, 1964), revealed that the initial TC uptake rate increased with increasingly TC dose in a nonlinear fashion, exhibiting saturation kinetics which obeyed the Michaelis-Menten equation. The initial maximal uptake rats (Vmax) was found to be 32.5 nmoles per s and g of liver, a value exceeding the maximal steady state capacity (Tm) for excretion of TC into the bile. The half-saturation constant (Km) was 90.6 nmoles per g of liver, indicating that this system is operating far from saturation at physiological levels of bile acids in portal blood.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.