Studies of zinc and histamine on lysosomal fragility: possible role in stress ulceration.

A combined in vivo and in vitro study was undertaken with rats to test the hypothesis that zinc would protect against cold water immersion--restraint gastric ulcers, and that this phenomenon was mediated in part by stabilization of lysosomal membranes. This postulate was confirmed by observed activity changes in released beta-glucuronidase in mucosal tissue, as well as by dose-response in vitro data on isolated hepatic lysosomes exposed to zinc. Histamine, a known ulcer-enhancing agent, induced the opposite effect and increased the lysosomal release of this marker acid hydrolase.