Gastric emptying and gastrointestinal transit during lactation in rats. Chen, Tseng-Shing, Ming-Luen Doong, Shyi-Wu Wang, Shiow-Chwen Tsai, Chien-Chen Lu, Hsi-Chang Shih, Yen-Hao Chen, Full-Young Chang, Shou -Dong Lee, and Paulus S. Wang. Graduate Institute of Clinical Research, Department of Physiology and Center for General Education, National Yang-Ming University; and Division of Gastroenterology,Department of Medicine, Veterans General Hospital-Taipei, Taipei and Department of Physiology, Chang Gung College of Medicine and Technology, Taoyuan, Taiwan, Republic of China
APStracts 3:0217G, 1996.
Female sex hormones can influence gastrointestinal function. To understand whether changes in female sex hormones during postpartum may affect such function, the gastric emptying and gastrointestinal transit were measured in rats on days 1-2, 10, 15, and 21 of lactation, on day 7 of postweaning, and at the non-pregnant diestrus stage. Gastric emptying and gastrointestinal transit were assessed in conscious rats 15 min after intragastric instillation of a test meal containing charcoal and 51Cr. The results showed that gastric emptying was increased throughout the first two weeks of lactation with gradual decrease as lactation proceeded toward weaning, and returned to the the level of the virgin rats by one week post weaning. Gastrointestinal transit was greater in the early stage of lactation, and related to gastric emptying (p<0.001). Increases in gastric emptying and intestinal length were correlated with lactation (p<0.001) and plasma prolactin levels (p<0.05) but not with the plasma progesterone or estradiol levels. We concluded that the sex steroid hormones associated with lactation do not mediate a change in gastric emptying and gastrointestinal transit during lactation.

Received 30 January 1996; accepted in final form 1 October 1996.
APS Manuscript Number G43-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996