AJP - Regulatory, Integrative and Comparative Physiology, Vol 267, Issue 5 1163-R1167, Copyright © 1994 by American Physiological Society
Effect of caloric content and composition of a liquid meal on gastric emptying in the rat
L. L. Maerz, H. Sankaran, S. J. Scharpf and C. W. Deveney
Surgical Service, Veterans Affairs Medical Center, Portland, Oregon 97207.
We examined the effect of caloric content and substrate composition on
gastric emptying in conscious Sprague-Dawley rats using gastric
radioscintigraphy. Three-milliliter volumes of normal saline, glucose,
casein hydrolysate, or intralipid containing 0, 1, 2, 3, or 6 kcal labeled
with 99mTc-diethylenetriaminepentaacetic acid were given intragastrically.
Gamma-camera imaging and computer analysis allowed construction of gastric
emptying curves constructed over many time points for each emptying study.
There was no difference in the half-emptying times (t1/2) between different
substrates with equal calories, and increasing calories significantly
prolonged gastric emptying for all substrates. Emptying occurred in a
linear fashion with meals containing calories. With 3-ml meals containing
2, 3, or 6 kcal, the rate of delivery of calories to the duodenum is
constant regardless of substrate or change in caloric content. We conclude
that the rate of caloric delivery to the small intestine with gastric
infusion of 1-6 kcal is relatively constant despite differences in total
caloric load, substrate composition, and osmolarity.
