Effects of dermorphin on gastrointestinal transit in rats

The effects of subcutaneous (s.c.) and intracerebroventricular (i.c.v.) injections of dermorphin on gastric emptying and intestinal transit were studied in rats. Dermorphin injected i.c.v delayed gastric emptying and this effect was dose-dependent. I.c.v. injections of dermorphin also inhibited intestinal transit but a dose level 5 to 10 times higher than that active on gastric emptying was required. Subcutaneous injections of dermorphin also inhibited gastrointestinal transit but inhibition of the two functions never exceeded 60%. The effect of i.c.v. and s.c. doses of dermorphin was antagonized by a 1 mg·kg-1 dose of naloxone s.c. The data suggest the possibility that dermorphin could affect gastrointestinal transit through an action on central and peripheral opiate receptors.