Polychlorinated biphenyl-induced morphologic changes in the gastric mucosa of the rhesus monkey.

The early morphologic events in polychlorinated biphenyl-induced lesions of the gastric mucosa of immature male rhesus monkeys (Macaca mulatta) were studied in serial biopsies taken during consumption of diets containing 3, 10, 30, and 100 mg. per kg. (p.p.m.) of Aroclor 1242. The severity of the lesions correlated directly with both the duration and the level of exposure. The first changes were seen after ingestion of 30 and 100 mg. per kg. for 2 weeks; changes were not seen until 10 weeks at 3 and 10 mg. per kg. The principal effect was an apparent arrest of the differentiation of generative cells of the isthmus and neck regions into parietal and zymogenic (chief) cells. Mature parietal and zymogenic cells were found only in the bases of the glands, where the oldest cells are normally found, and these showed signs of injury including dilation of the rough endoplasmic reticulum in zymogenic cells, irregularity of the mitochondria in parietal cells and irregular luminal membranes, and an increase in the number of large autophagic vesicles in both cell types.