Stimulatory effect of prostaglandin F2 alpha on gastric acid secretion in rats

The effect of intravenously administered prostaglandin F2 alpha on gastric acid secretion was investigated in anaesthetized rats. Doses of 0.03-0.3 mg/kg PGF2 alpha stimulated gastric acid output in rats with intact vagi, whereas an inhibitory effect was observed in vagotomized animals. Treatment with 5 mg/kg of Na-meclofenamate intravenously attenuated the secretory response to PGF2 alpha, while 10 mg/kg of indomethacin intravenously and 3 mg/kg of 8-phenyltheophylline intraperitoneally were without any effect. The results indicate that intravenously administered PGF2 alpha stimulates gastric acid secretion in anaesthetized rats via activation of the vagus nerve. The effects of Na-meclofenamate and indomethacin suggest that PGF2 alpha may exert its secretagogue action via specific receptors. The lack of the effect of 8-phenyltheophylline indicates that adenosine which reportedly had a similar effect on gastric secretion after intravenous injection seems not to be involved here.