Inhibitory Effects of B-HT 920 on Gastric Acid Secretion Induced by Vagal Stimulation in Rat

  • Hong, Sung-Cheul (Department of Pharmacy, College of Pharmacy, Pusan National University) ;
  • Park, Mi-Sun (Department of Pharmacy, College of Pharmacy, Pusan National University) ;
  • Chung, Joon-Ki (Department of Pharmacy, College of Pharmacy, Pusan National University) ;
  • Kang, Maeng-Hee (Department of Pharmacy, College of Pharmacy, Pusan National University) ;
  • Choi, Su-Kyung (Department of Pharmacy, College of Pharmacy, Pusan National University) ;
  • Kim, Myung-Woo (Department of Pharmacy, College of Pharmacy, Pusan National University)
  • Published : 1989.12.01

Abstract

Effects of B-HT 920 on the vagally stimulated gastric acid secretion were studied in anesthetized and gastric fistula rats. When the gastric acid secretion was increased by stimulation of the vagus nerve, B-HT 920 was partially attenuated by prazosin, $\alpha_1-$adrenoceptor antagonist and virtually abolished by yohimbine, $\alpha_2-$adrenoceptor antagonist. On the other hand, when the gastric acid secretion was increased by the infusion of bethanechol, a muscarinic parasympathetic stimulant, B-HT 920 had no effect on the bethanechol-induced gastric acid secretion. These results suggest that B-HT 920 inhibits vagally induced gastric acid secretion by activation of presynaptic $\alpha-$adrenoceptors located on the vagally stimulated pathways in the gastric wall and this effect of B-HT 920 is more related to $\alpha_2-$adrenoceptors than $\alpha_1-$adrenoceptors.

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