Secretin inhibits vagal afferent nerve discharge in response to gastric distension in rats / 重庆医科大学学报

ABSTRACT

Objective:To study the effect of secretin on subdiaphragmatic vagal afferent response by gastric distension. Methods: Experiments were performed on anesthetized rats. The sensory impulses of subdiaphragmatic vagal nerve were recorded using a window discriminator. Through a midline abdominal incision, a polyethylene cannula (1.0mm ID) for duodenal infusion was inserted into the proximal duodenum 0.5mm distal to the pylorus.Another cannula was placed into jejunum 20 cm distal to the ligament of Treitz.Gastric distension was produced by injecting saline at 37℃ into a small balloon via a polyvinyl tube.Results:Intravenous injection of secretin in a dose of 5.0 pmol/kg/h inhibited significantly the response of afferent discharges induced by gastric distension( n=7, P 0.05). It showed that exogenous secretin in a dose of 5.0pmol/kg/h, in the physiological dose range, played an inhibitory effect. 0.03N HCl was infused intraduodenally at 9 ml/h for 20 min in anesthetized rats with gastric cannulas, ligation of the pylorus, respectively.0.1 ml of a rabbit antisecretin serum (titer=ll,000,000) was injected intravenously in a bolus 20～40min before HC1 was administered. During the duodenal infusion of 0.03N HCI the gastric distension-vagal afferent responses were suppressed significantly.( n=8, P