Reduction of the nociceptive response to gastric distension by nitrate ingestion in rats.

Background: Dietary nitrates are known to produce nitric oxide in the stomach, which may influence gastric function.

Aim: To investigate whether nitrate ingestion modifies gastric sensitivity to distension through a mechanism involving nitric oxide production.

Methods: Nociception, associated with gastric distension ranging from 10 to 40 mmHg, was assessed in anaesthetized rats by the amplitude of cardiovascular depressor responses.

Decrease in gastric sensitivity to distension by 5-HT1A receptor agonists in rats.

Using an in vivo model for evaluation of gastric sensitivity in awake rats, we aimed to determine whether 5-hydroxytryptamine 1A (5-HT1A) agonists modify pain threshold and gastric compliance specifically through 5-HT1A receptors. Isobaric gastric distensions were performed with a barostat using steps of 5 mm Hg in male rats equipped with a gastric balloon and electrodes implanted in the neck muscles. Gastric distension at 15 or 20 mm Hg induced a typical posture associated with contractions of the neck muscles.

A model for evaluation of gastric sensitivity in awake rats.

We developed a model for the evaluation of gastric sensitivity to distension in awake rats. A balloon made from a latex condom was chronically placed in the stomach and three stainless steel electrodes were implanted in the neck muscles. Isobaric distensions were performed with a barostat by step of 5 mmHg with 10 min inflation and 2 min deflation.

[Role of 5-HT3 receptors in the control by cholecystokinin of transient relaxations of the inferior esophageal sphincter in dogs].

Aims: The aim of this study was to determine, using specific antagonists, whether 5-HT3 receptors participate in triggering transient lower esophageal sphincter relaxations, independently or in relation with their CCKergic control.

Methods: Esophageal, lower esophageal sphincter and fundus pressure were manometrically monitored in 5 conscious dogs. Gastric distensions with air at constant pressure (1.