Apolipoprotein a-iv acts in the brain to inhibit gastric emptying in the rat. Okumura, Toshikatsu, Koji Fukagawa, Patrick Tso, Ian L. Taylor, and Theodore N. Pappas. Department of Surgery, Duke University Medical Center and Veterans Administration Medical Center, Durham, NC 27710, Department of Physiology, Louisiana State University Medical Center, Shreveport, LA 71130 and Department of Medicine, Medical University of South Carolina, Charleston, SC 29425
APStracts 2:0133G, 1995.
We have very recently shown that intracisternal injection of apolipoprotein A-IV (apo A-IV), a glycoprotein produced in the small intestine by fat, dose-dependently inhibited gastric acid secretion in pylorus-ligated conscious rats. These results suggest that apo A -IV acts centrally as a neuromodulator to inhibit gastric secretion. The present study was carried out to examine the hypothesis that apo A-IV acts centrally to alter gastric emptying. Twenty four hr-fasted rats received intracisternal injection of apo A-IV and a liquid meal by oral intubation under brief isoflurane anesthesia. Gastric emptying of a liquid meal was determined by the phenol red method. Intracisternal injection of apo A-IV inhibited gastric emptying of a liquid meal in a dose-dependent manner (1.0 - 4.0 [mu]g). On the other hand, apo A-I in a dose of 4 [mu]g failed to change gastric emptying. Gastric emptying was not altered by intraperitoneal administration of apo A-IV in a dose of 15 [mu]g. These results suggest that apo A-IV acts centrally to delay gastric emptying of a liquid meal. Together with our recent finding that apo A-IV acts centrally to inhibit gastric acid secretion, the present study supports our hypothesis that apo A-IV may be involved in lipid -induced inhibition of gastric function.

Received 12 December 1994; accepted in final form 27 June 1995.
APS Manuscript Number G483-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.