RESUMO
A single administration of chlorophos (trichlorophon) solution (600 mg/kg) (LD50) results in vacuolar distrophy appearing in the white rat liver and is especially pronounced in 2-4 days. Thirty minutes after the poisonous chemical is administered, butyrilcholinesterase (BChE) activity is inhibited by 90%, somewhat later oxidation-reduction enzymes activity decreases and alkaline phosphatase (APh) activity increases. Cytoplasm of hepatocytes is filled with glycogene and nearly deprived of RNA. Owing to the cytophotometric analysis of the enzymatic activity and the stereologic morphometry method, it has been possible to reveal a certain synchronism in the development of distrophic processes, in a decreasing activity of the oxidation-reduction enzymes and in a disturbed synthesis of glycogene and RNA. On the 6th day after chlorophos has been administered, succinate dehydrogenase and nicotinamide-adenine-dinucleotide-phosphate-diaphorase activity, as well as contents and distribution of RNA in hepatocytes reach their control values. BChE and APh activity does not restore. During the whole experiment there is not any statistically significant change in the volumetric part of the sinusoid capillaries and in the stellate reticuloendotheliocytes. Thus, the main effect of chlorophos action is a specific inhibition of ChE, that results in certain structural changes and in changes of the histoenzymatic parameters of the liver.