Cytoprotection by PGE2, pirenzepine or vagotomy: a transmission and scanning electron microscopic study in rats.

We have studied the effects of PGE2, the anticholinergic pirenzepine and vagotomy on the rat gastric mucosa after challenge with ASA+0.15N HCl or absolute ethanol. The damage was evaluated by quantitative macroscopic examination, light and electron (transmission and scanning examinations) microscopy. We found both macroscopically and microscopically that pirenzepine and PGE2 were effective against ASA+0.15N HCl, but under microscopic examination they were seen to be uneffective 1 hr after absolute ethanol. Vagotomy showed some protection against ASA+0.15N HCl but was totally uneffective against absolute ethanol. The results stress the differences between ASA+0.15N HCl and absolute ethanol damage and show that "cytoprotection" is possible when the mucosa is challenged with noxious agents that do not act by hyperosmolar effects.