Biochemical changes in the rat after chronic thioacetamide intoxication.

Male Wistar rats were given drinking water ad libitum with 0.075% thioacetamide (TAA) for 4 weeks. TAA treatment did not affect serum aminotransferase activities and total bilirubin content. The activities of 5'-nucleotidase, K+, Na+- and Mg2+-adenosine triphosphatases in liver plasma membrane preparations were strongly depressed, while that of gamma-glutamyl transferase was considerably increased. A decline in liver microsomal cytochrome P-450 and cytochrome b5 concentrations was also recorded. In contrast, the content of reduced glutathione in liver homogenate supernatant (9000 g) increased about 2-fold. As plasma membrane associated enzymes seem to be exclusively affected, the liver plasma membrane could be involved in the pathogenesis of the TAA-induced precirrhotic liver changes.