Prostaglandin-lnduced Protection of Cultured Rat Gastric Cells against Ethanol Is Inhibited by a Microtubule Inhibitor

Abstract

Prostaglandins reduce damage by noxious agents to isolated gastric cells. The mechanism remains unexplained. This study was done to examine involvement of microtubules with prostaglandin-mediated cell protection. Cultured mucus-producing cells of rat gastric mucosa were used. Cultured cells were incubated with 16,16-dimethyl-prostaglandin E₂ (dmPGE₂), colchicine, or vehicle alone in calcium-containing (1.3 mM) and calcium-free medium. The cells were then exposed to 8% ehtanol. Cell integrity and damage were assessed by ⁵¹Cr release and in part by transmission electron microscopy (TEM). Specific ⁵¹Cr release was closely related to percentage change of necrotic cells assessed by TEM. Cell damage caused by 8% ethanol was greater in medium-containing calcium than in calcium-free medium. dmPGE₂ at 10^-5M inhibited cell damage in calcium-containing medium. Colchicine itself at concentrations up to 10^-5M did not affect cell integrity, but at 10^-5M concentration potentiated damage caused by 8% ethanol in calcium-containing medium. Pretreatment with 10^-5M colchicine abolished the protective effect of dmPGE₂. Microtubules may mediate protection by dmPGE₂ of cultured gastric cells against ethanol damage.

Enhanced Intracellular Calcium Promotes Metabolic and Secretory Disturbances in Rat Gastric Mucosa during Ethanol-Induced Gastritis

“…In vitro. external Ca 2+ exacerbates ethanol-induced damage in gastric mucosal samples (46), and Ca 2+ channel blockers exert protection for gastric mucosa against the deleterious effect of ethanol (26,47.48). In contrast.…”