Nonprotein sulfhydryl compounds in canine gastric mucosa: effects of PGE2 and ethanol.

By use of an in vivo canine chambered stomach preparation in which the gastric mucosa was partitioned into two equal halves, the effect of topical 16,16-dimethyl PGE2 (DMPGE2) (1 microgram/ml of perfusate) and 8% and 40% ethanol on tissue levels of nonprotein sulfhydryl compounds was assessed. Both DMPGE2 and 8% ethanol significantly increased (P less than 0.005) mucosal levels of nonprotein sulfhydryls when compared with corresponding mucosa bathed with saline alone.

Failure of 16,16-dimethyl PGE2 to prevent inhibitory effect of ethanol on sodium transport in canine gastric mucosa.

By use of an in vitro canine gastric mucosal preparation, we evaluated the effects of ethanol (2, 4, 6, and 8%, vol/vol) and indomethacin (2.2 X 10(-4)M), with and without 16,16-dimethyl PGE2 pretreatment, on net sodium transport (JNanet) (mucosal to serosal) across gastric epithelium. Although administration of 2 or 4% ethanol to the mucosal bathing solution had no appreciable inhibitory effects on sodium transport, 6 and 8% ethanol and indomethacin significantly inhibited JNanet when compared with untreated control mucosa.

Sodium transport in Rana pipiens gastric mucosa.

The transport properties of frog gastric mucosa in vitro have been reexamined in conditions analogous to those used in studies on mammalian systems in which net movements of sodium were observed. Net transport of sodium across frog gastric mucosa was not observed to occur when the mucosal surface was bathed with a well-buffered solution of near neutral pH, indicating that failure to demonstrate sodium transport across frog stomach in previous work could not be ascribed to the low pH value of the solution usually used as the mucosal fluid. Addition of 5 X 10(-4) M amphotericin B to the mucosal solution elicited net transport of sodium and an increase in short-circuit current.

Prevention of the inhibitory effects of aspirin on sodium transport in canine gastric mucosa by prostaglandin. Correlation with mucosal morphology.

Using an in vitro canine gastric mucosal preparation, this study evaluated the effects of 1 mM aspirin in a buffered Ringer solution (pH = 7.4), with and without concomitant prostaglandin (PG) treatment, on net sodium transport (mucosa to serosa) across gastric epithelium. Administration of aspirin to the mucosal bathing solution for 2 hr significantly decreased the potential difference (PD), short circuit current (Isc), and net sodium transport (net J-Na+) when compared with untreated control mucosa.

Effects of 16,16-dimethyl prostaglandin E2 on alkaline secretion in isolated canine gastric mucosa.

An isolated fundic mucosal preparation of dog stomach which is capable of exhibiting an alkaline secretion is described. A stable secretion was established 40 min to 1 hr after the mucosa was pretreated with the H2-antagonist cimetidine to block spontaneous acid output. Alkaline secretion decreased when Ca2+ was removed from the nutrient solution.