Central nervous system effects of arachidonic acid, PGE2, PGF2 alpha, PGD2 and PGI2 on gastric secretion in the rat.

The effects of arachidonic acid, prostaglandin E2 (PGE2), PGF2 alpha, PGD2 and PGI2 on gastric secretion (acid, pepsin and volume) after intracerebroventricular administration were investigated in conscious, pylorus-ligated rats. Arachidonic acid 30-1000 micrograms had no effect on gastric secretion. PGE2 3 and 10 micrograms, reduced gastric secretion as measured 1 hour after injection, although the inhibition induced by 3 micrograms disappeared by 2 h. PGF2 alpha 10 and 30 micrograms, inhibited gastric secretion as measured after 1 h, whereas no change was observed in the gastric contents collected 2 h after 10 micrograms of PGF2 alpha. Intramuscular injection of 30 micrograms of PGF2 alpha had no effect on gastric secretion. Intracerebroventricular administration of 1-30 micrograms of PGD2 or PGI2 had no effect on gastric secretion. The results indicate that PGE2 and PGF2 alpha have a potent central antisecretory action in conscious, pylorus-ligated rats, whereas arachidonic acid, PGD2 and PGI2 do not have any central effects on gastric secretion. It is suggested that PGE2 and PGF2 alpha may be involved in the central nervous system control of gastric secretion.