EFFECT OF MORPHINE AND ENKEPHALIN ON BASAL GASTRIC ACID SECRETION IN THE RAT

This study was undertaken to examine the acid secretion in response to intra-venous injection of morphine or Leu-enkephalin under basal conditions.Acuteexperiments were performed,the technic of Ghosh and Schild was essentiallyused.The stomach of the rat anesthetized with urethane was perfused with salineat 37℃ at a uniform rate.The perfusate collected every 10 minutes from thepyloric end of the stomach was titrated for acidity.It was found that both morphine and Leu-enkephalin caused increase in basalacid secretion.The maximal acid response after morphine and Leu-enkephalininjection was observed at 30 and 20 minutes respectively.The acid stimula-tory effect of morphine was completely blocked by naloxone at a dose of 1.5-2.6mg/kg.However,a significant rise in morphine-induced acid secretion was ob-served when an increased dose(3-5 mg kg)of naloxone was used.