Taurolithocholate can inhibit the biliary discharge of lysosomes in the rat

RAUL A. MARINELLI; JOSE M. PELLEGRINO; MARIA C. LAROCCA

BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS

Elsevier

Año: 1997 vol. 1334 p. 155 - 160

0304-4165

The natural bile salt taurolithocholateTLC.impairs the biliary excretion of lipids and proteins, which are known to reach the canaliculus via vesicles. In this study we examined whether these observations could be extended to the exocytic discharge of lysosomal contents into bile. The single intravenous injection of a cholestatic dose of TLC, 3 mmolr100 g body wt., markedly inhibited the biliary excretion of the lysosomal enzymes acid phosphatase and b-glucuronidase, despite the excretion of bile salts being normalized after a transient diminution. Under such a condition, TLC did not affect the normal transport to and the processing in lysosomes of the exogenously administered w14Cxsucrose-labeled horseradish peroxidase. However, the biliary excretion of the radioactive lysosomal metabolites of the protein was significantly reduced. The results indicate that TLC can inhibit the biliary discharge of lysosomes in the rat without altering the functional integrity of these organelles. Possible explanations for these findings are discussed.TLC.impairs the biliary excretion of lipids and proteins, which are known to reach the canaliculus via vesicles. In this study we examined whether these observations could be extended to the exocytic discharge of lysosomal contents into bile. The single intravenous injection of a cholestatic dose of TLC, 3 mmolr100 g body wt., markedly inhibited the biliary excretion of the lysosomal enzymes acid phosphatase and b-glucuronidase, despite the excretion of bile salts being normalized after a transient diminution. Under such a condition, TLC did not affect the normal transport to and the processing in lysosomes of the exogenously administered w14Cxsucrose-labeled horseradish peroxidase. However, the biliary excretion of the radioactive lysosomal metabolites of the protein was significantly reduced. The results indicate that TLC can inhibit the biliary discharge of lysosomes in the rat without altering the functional integrity of these organelles. Possible explanations for these findings are discussed.