Rapid synthesis and secretion of intestinal apolipoprotein a-iv
after gastric fat loading in rats.
Rodriguez, Maria-Dolores, Theodore J. Kalogeris, Xiao-Lin Wang, Robert
Wolf, and Patrick Tso.
Departments of Physiology and Biophysics and Medicine, Louisiana
State University, Medical Center, Shreveport, Louisiana 71130
APStracts 3:0416R, 1996.
In order to further investigate the possible role of apolipoprotein A
-IV in the short-term control of food intake, we examined the kinetics
of intestinal apo A-IV synthesis and release into lymph and plasma
after intragastric delivery of physiological amounts of lipid. Within
30 min of intragastric administration of 0.1 g of triglyceride,
plasma and lymph levels of apo A-IV were similar to those produced by
exogenous apo A-IV that inhibit food intake. Within 15 min 5% of
gastrically-delivered radioactive lipid reached the distal small
bowel and cecum; by 30 min radioactivity was evenly distributed
throughout the small intestine, with 10-15% of the load in the distal
gut. By 30 min, synthesis of apo A-IV was significantly stimulated in
proximal and distal jejunum, and distal ileum, and remained elevated
up to 4 h after the delivery of lipid. Our results indicate that the
delivery of physiological amounts of lipid into the stomach produces
a significant and rapid stimulation of apo A-IV secretion into lymph
and plasma, together with a rapid delivery of lipid and increases in
mucosal synthesis of apo A-IV along the entire length of the small
intestine. The results support a possible role for apo A-IV in the
short-term control of food intake, and suggest a role for the entire
gut in the integrative response of apo A-IV to a fat meal.
Received 27 August 1996; accepted in final form 12 November 1996.
APS Manuscript Number R519-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996