No abstract

The effect of somatostatin (GH-RIH) infusion (2 microgram/min) on lower esophageal sphincter pressure (LESP) responses to various stimuli was evaluated in adult male baboons. GH-RIH infusion did not affect basal LESP, but did cause a significant suppression of mean immunoreactive insulin (IRI) to 5.8% of basal values (P less than 0.05). Pentagastrin IV caused dose-related increases in LESP that were unaffected by GH-RIH. Abdominal compression caused a threefold rise in LESP (P less than 0.005) both without and with GH-RIH. However, atropine (20 microgram/kg iv bolus) completely blocked this cholinergic LES pressure response. Intragastric alkali as well as intragastric glycine caused significant increases in LESP (P less than 0.05). These LESP responses to alkali and to glycine were totally abolished by GH-RIH. In conclusion, GH-RIH infusion in the baboon does not affect basal LESP, LES smooth muscle response to exogenous stimulation, nor a cholinergically mediated LES response. GH-RIH does inhibit the response of LESP both to intragastric alkali and to glycine by the apparent suppression of a hormonally mediated mechanism.

Acid-induced esophageal injury in the cat, produced by infusion of 0.1 N HCl (1 ml/min for 30 min) on 4 consecutive days, has been shown previously to adversely affect lower esophageal sphincter (LES) pressure. We studied the role of prostaglandins in acid-induced esophagitis and the associated LES hypotension by simultaneous treatment of some animals with indomethacin (150 micrograms/kg intravenous), a specific inhibitor of prostaglandin synthesis, either during production of esophagitis or during recovery. LES pressures and esophageal histology were compared to control groups which received acid alone. Indomethacin treatment resulted in more rapid healing of the esophageal inflammation and prevented or promptly corrected the esophagitis-associated LES hypotension. These studies provide further evidence that prostaglandins play an important role in the pathogenesis of acid-induced esophagitis and LES hypotension and raise the possibility that indomethacin, a prostaglandin synthetase inhibitor, may be of benefit in prevention or therapy of esophagitis.