Liver histology in chronic metribuzin poisoning of the guinea-pig.

Forty male guinea-pigs weighing 400-600 g, 8 months old, were given metribuzin directly into the gastric lumen over a period of 30 days (20 animals) or 90 days (20 animals), 6 times a week. The intoxicated animals showed congestion and obliteration of the trabecular structure of the liver. Acidophilic and vacuolar degeneration of the liver cells with signs of necrosis were also observed. Histochemical tests revealed a poorer staining for glycogen and succinic dehydrogenase and intensification of the alkaline and acid phosphatases reaction. The above findings indicate a progressive degeneration due to metribuzin of different organelles of the liver cells including nuclei, mitochondria, lysosomes, microvilli and the cytoplasm.