Induction of heat shock protein 72 by a nitric oxide donor in guinea-pig gastric mucosal cells.

Gastric mucosal cells may be exposed to exogenous nitric oxide (NO) from a variety of sources. The response of primary cultures of guinea-pig gastric mucosal cells to the NO donor S-nitroso-N-acetyl-penicillamine was therefore investigated. Exposure to S-nitroso-N-acetyl-penicillamine for 8 h caused a concentration-dependent induction of heat shock protein 72 (HSP 72). Induction was inhibited by the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, and by blockade of transcription with actinomycin D. Induction of HSP 72 by S-nitroso-N-acetyl-penicillamine was enhanced by diethyl maleate which decreased the intracellular reduced thiol content. By contrast, HSP 72 formation after heat shock was associated with an elevation of reduced thiol. Incubation with S-nitroso-N-acetyl-penicillamine for 18 h increased detachment of cells from the culture plate. The effect of S-nitroso-N-acetyl-penicillamine on detachment was exacerbated by the presence of actinomycin D. In conclusion, exogenous NO induces HSP 72 in guinea-pig gastric mucosal cells and this response may in part protect the cells from the deleterious effects of NO.