Effect of dioctyl sodium sulfosuccinate on cyclic AMP and prostaglandin E2 contents, and Na,K-ATPase, adenylate cyclase and phosphodiesterase activities in rat intestine

Abstract

The hypothesis that dioctyl sodium sulfosuccinate (DSS) induces intestinal fluid accumulation by inhibiting Na,K-ATPase activity and/or by increasing mucosal prostaglandin E2 (PGE2) content was tested in rats. Eighteen hours after its intragastric administration, DSS (260 mg/kg body weight) significantly decreased jejunal and colonic Na,K-ATPase activity--22.0 1.8 (SE) and 25.1 +/- 3.3 compared with 42.1 +/- 1.6 and 37.0 +/- 2.9 mumol . mg protein-1 . h-1, respectively, in saline-treated rats. DSS increased jejunal and colonic PGE2 content--155 +/- 15 (SE) and 273 +/- 40, compared with 109 +/- 9 and 175 +/- 23, pg/mg wet weight, respectively, in control rats. Although jejunal adenylate cyclase and phosphodiesterase activities were not affected by DSS (520 mg/kg body weight), they were significantly stimulated in the colon. Mucosal cyclic AMP content was similar in rats treated with DSS and saline. Patchy histological changes confined to surface absorptive cells were induced by DSS in both the jejunum and the colon. These findings suggest that inhibition of intestinal Na,K-ATPase activity and increase in mucosal PGE2 content might contribute to the net water accumulation induced in the rat intestine by DSS.