Role of the antrum in the gastric emptying of a non-nutrient liquid in the rat.

Forty male Wistar rats underwent liquid gastric emptying analysis with a non-nutrient liquid--99mTC-tin colloid in physiologic saline. Twenty then had two-thirds resection of the glandular stomach with Billroth-II-type reconstruction. Twenty served as controls: 10 unoperated and 10 with a laparotomy alone. Emptying was studied weekly for 4 weeks, then monthly for 4 months. Emptying was unchanged in unoperated controls. Laparotomy alone caused delayed emptying for 2 months (p less than 0.05). After Billroth-II resection emptying was delayed for 4 months (p less than 0.01). This delay included both the early and late phases of gastric emptying. We conclude that a laparotomy alone delays gastric emptying. The addition of an antrectomy causes a greater emptying delay, which persists for longer than that due to laparotomy alone. Thus, in a situation in which the small bowel and gastric feedback mechanisms are inoperative, the antrum is seen to play an important role in the gastric emptying of liquids. This supports the concept in man that antral contractions are important in ensuring the normal active emptying of liquids from the stomach.