Effect of taurine administration on liver lipids in guinea pig

The oral administration of 0.4% taurine in drinking water for 14 consecutive days showed the following hepatic effects in male guinea pig. The percentage of tauro-conjugated biliary bile acids was increased from 17.2-54.2%; the ratio liver weight/body weight was increased, and fatty change was induced. Liver triglyceride concentration was accordingly increased; diglyceride and phosphatidylcholine concentrations were reduced by the treatment, while phosphatidylethanolamine level was not affected. These changes suggest an adverse effect of taurine administration on phosphatidylcholine hepatic synthesis.     

Hepatic phosphatidylcholine synthesis in deficiency of lysine and threonine: effect of malathion

Summary Rats fed on a rice diet deficient in lysine and threonine showed increased activities of CDP-Choline pathway enzymes and incorporation of (methyl-³H)-choline into hepatic microsomal phosphatidylcholine, compared to rats fed on the same diet supplemented with lysine and threonine. However, the amount of microsomal phosphatidylcholine was significantly decreased in rats fed a deficient rice diet. These results suggest an enhanced phosphatidylcholine catabolism in rats fed on a rice diet deficient in lysine and threonine. Malathion administration reduced the amount of phosphatidylcholine in all the groups.     

Hepatic phosphatidylcholine synthesis in deficiency of lysine and threonine: effect of malathion

Rats fed on a rice diet deficient in lysine and threonine showed increased activities of CDP-Choline pathway enzymes and incorporation of (methyl-3H)-choline into hepatic microsomal phosphatidylcholine, compared to rats fed on the same diet supplemented with lysine and threonine. However, the amount of microsomal phosphatidylcholine was significantly decreased in rats fed a deficient rice diet. These results suggest an enhanced phosphatidylcholine catabolism in rats fed on a rice diet deficient in lysine and threonine. Malathion administration reduced the amount of phosphatidylcholine in all the groups.     

Potentiation by taurine of the inotropic effect of ouabain and the content of intracellular Ca++ and taurine in the heart

Summary Under certain conditions, taurine (3.0 mM) potentiated cardiac contractile response to ouabain in the normal medium. The potentiation by taurine was also observed in the low K⁺ medium, in which the positive inotropic effect of ouabain increased. The potentiation as seen in both media was, at least in part, due to the increase by taurine of Ca⁺⁺ content in the heart. Taurine in the heart was not directly related to this potentiation.     

Potentiation by taurine of the inotropic effect of ouabain and the content of intracellular Ca++ and taurine in the heart.

Under certain conditions, taurine (3.0mM) potentiated cardiac contractile response to ouabain in the normal medium. The potentiation by taurine was also observed in the low K+ medium, in which the positive inotropic effect of ouabain increased. The potentiation as seen in both media was, at least in part, due to the increase by taurine of Ca++ content in the heart. Taurine in the heart was not directly related to this potentiation.     

Effect of ethanol on taurine concentration in the brain

Summary The taurine concentration in the brain was decreased in ethanol-dependent rats, but returned to normal soon after withdrawal of ethanol. It was not affected by acute ethanol administration.This research was supported by a grant from the Taisho Pharmaceutical Co., Ltd., Tokyo.     

Cimetidine induces hepatic heme oxygenase activity without altering hepatic heme catabolism

Summary Cimetidine inhibits oxidative drug metabolism; it is not known whether this drug alters the catabolic fate of hepatic heme. We therefore investigated hepatic heme turnover both by a¹⁴CO breath test and directly by labeling the heme pool. Neither acute (150 mg/kg i.p.) nor chronic (150 mg/kg i.p. bid for 3 days) cimetidine administration significantly affected hepatic heme turnover. Chronic, but not acute, cimetidine significantly (p<0.025) increased heme oxygenase activity. Cimetidine inhibited heme oxygenase activity in vitro at concentrations achieved in vivo.     

Cimetidine induces hepatic heme oxygenase activity without altering hepatic heme catabolism

Cimetidine inhibits oxidative drug metabolism; it is not known whether this drug alters the catabolic fate of hepatic heme. We therefore investigated hepatic heme turnover both by a 14CO breath test and directly by labeling the heme pool. Neither acute (150 mg/kg i.p.) nor chronic (150 mg/kg i.p. bid for 3 days) cimetidine administration significantly affected hepatic heme turnover. Chronic, but not acute, cimetidine significantly (p less than 0.025) increased heme oxygenase activity. Cimetidine inhibited heme oxygenase activity in vitro at concentrations achieved in vivo.     

Effect of taurine on mitogen response of human lymphocytes

Summary Taurine selectively inhibits the phytohemagglutinin-stimulated incorporation of³H-thymidine by human cultured lymphocytes (50% inhibition by 12.5 mM taurine). Decreasing effects of taurine on Na–K ATPase activity or on calcium accumulation by lymphocytes might be responsible for its action on cell proliferation.Thanks are due to Mr F. Cervantes Salas for technical assistance. This work was partly supported by grants. No. 5 RO1-EY 02540-02 from the National Eye Institute and No. PCCBNAL 790219 from CONACyT.     

Similarities between metallothionein and low molecular weight testicular cadmium-binding protein

Summary The incorporation of³⁵S-cysteine and³H-glutamic acid was studied in mouse hepatic and renal metallothionein and in testicular cadmium-binding protein of similar molecular weight. Preferential incorporation of³⁵S-cysteine over³H-glutamic acid was observed not only in hepatic and renal metallothionein, but also in testicular cadmium-binding protein. When the antigenic reactivity of these proteins was compared, all three proteins reacted with the metallothionein antibody. These similarities suggest that the low molecular weight testicular cadmium-binding protein is apparently metallothionein.     

Glomerular filtration rate and kidney blood flow in alloxan and streptozotocin diabetic rats.

Glomerular filtration rate (GFR), cardiac output, regional blood flow and kidney weight were measured in alloxan and streptozotocin diabetic rats at different times after the administration of diabetogen. A high GFR was found together with increased kidney weight and reduced blood flow.     

Liver function during chronic renal failure in rabbits

Summary In rabbits with chronic renal insufficiency the prothrombin index was increased by 25% and the alanine aminotransferase activity decreased by 20%; the results of other routine tests of hepatic function were not affected. The galactose elimination capacity was decreased by 12%, whereas the body clearance of antipyrine was unchanged. No change in hepatocytic structure was found.     

Liver function during chronic renal failure in rabbits

In rabbits with chronic renal insufficiency the prothrombin index was increased by 25% and the alanine aminotransferase activity decreased by 20%; the results of other routine tests of hepatic function were not affected. The galactose elimination capacity was decreased by 12%, whereas the body clearance of antipyrine was unchanged. No change in hepatocytic structure was found.     

Glomerular filtration rate and kidney blood flow in alloxan and streptozotocin diabetic rats

Summary Glomerular filtration rate (GFR), cardiac output, regional blood flow and kidney weight were measured in alloxan and streptozotocin diabetic rats at different times after the administration of diabetogen. A high GFR was found together with increased kidney weight and reduced blood flow.     

The synthesis of total and specific glycosaminoglycans during development of experimental liver cirrhosis

Summary During hepatic fibrogenesis induced by long-term administration of thioacetamide, the synthsis of chondroitin 4,6-sulfate and hyaluronic acid was strongly enhanced; the formation of heparan sulfate comprising at least 70% of total liver GAG synthesis and of a keratan-sulfate-like fraction was stimulated 1.7fold. Formation of dermatan-sulfate in liver could not be detected.We are grateful to Prof. W. Kühnel, Department of Anatomy, and to Prof. R. Lindenfelser, Department of Pathology, RWTH Aachen, for critical examination of the histology.     

Inhibitory effect of taurine on decrease in the inotropic action of ouabain at high concentrations in isolated atria

Summary In vitro, taurine was shown to inhibit the decrease in the inotropic effect of ouabain at large doses in the normal and also low K⁺ medium in which this decrease in the inotropism of ouabain was facilitated. This inhibitory effect of taurine was, at least in part, due to the inhibition of the efflux of intracellular K⁺ in the isolated heart.     

Prednisolon-Na-succinat und die Phagozytose der Leukozyten

Summary Intravenous administration of 3 mg/kg body weight prednisolon-Na-succinate (P) decreased, after 24 h, by 30% the bacterial phagocytosis of leukocytes of rabbits. After 48 h, the effect became a slight increase. At a dosis of 0.3 mg/kg, P exerts a stimulating effect which ceases within some hours. Inin vitro experiments, it showed increased or decreased action depending upon the concentration. When perfused through the liver, the efficacy of P rises strikingly.     

Effects of L-lysine administration on certain aspects of ascorbic acid metabolism in weanling rats

Summary L-lysine administration to male weanling rats at a dose of 110.4 mg (25% LD₅₀) per 100 g body weight per day for 15 days reduced the liver total ascorbic acid level. The biosynthesis as well as the degradation of L-ascorbic acid was diminished under these conditions. The fall in liver total ascorbic acid level after L-lysine administration was ascribed to its reduced synthesis.Acknowledgment. The authors are thankful to the Council of Scientific and Industrial Research, India, for providing Junior Research Fellowships to Miss J. Basu and Miss K. Sen Gupta.     

Effect of taurine on mitogen response of human lymphocytes

Taurine selectively inhibits the phytohemagglutinin-stimulated incorporation of 3H-thymidine by human cultured lymphocytes (50% inhibition by 12.5 mM taurine). Decreasing effects of taurine on Na-K ATPase activity calcium accumulation by lymphocytes might be responsible for its action on cell proliferation.     

Lowering of liver acetaldehyde but not ethanol concentrations by pretreatment with taurine in ehtanol-loaded rats

Summary A rise in blood and liver acetaldehyde concentrations following ethanol loading (1.5 g/kg b.wt) was significantly reduced when rats were pretreated orally with taurine (0.5 g/kg), a potent in vitro activator of yeast aldehyde dehydrogenase. This taurine pretreatment produced a 4-fold increase in liver taurine content.