AJP - Regulatory, Integrative and Comparative Physiology, Vol 263, Issue 4 813-R819, Copyright © 1992 by American Physiological Society
Dynamics of gastric emptying during and after stomach fill
J. M. Kaplan, A. C. Spector and H. J. Grill
Department of Psychology, University of Pennsylvania, Philadelphia 19104.
Gastric contents were sampled at various points during and after
intragastric infusions of glucose solution (6.25, 12.5, 25%) delivered at
rates typical of normal ingestion in the rat. The postinfusion results were
consistent with those reported in the literature in that glucose solute
emptied at a relatively stable rate over time and across stimulus
concentrations. During fill (1.0 ml/min; experiment 1), by contrast, solute
(caloric) emptying rate increased about threefold as stimulus concentration
was raised. For each concentration, emptying rate was uniformly higher
during than after fill (approximately 4 times higher at the lowest
concentration). In experiment 2, gastric emptying rate during 12-min
intragastric infusions of 12.5% glucose varied directly with the volumetric
rate (0.5, 1.0, 2.0 ml/min) at which they were delivered. These results
show that different rules govern gastric emptying during and after stomach
fill. The results also suggest that a large proportion of a liquid meal may
empty before feeding is terminated and that variations in the rate of
ingestion could affect the gastric/postgastric distribution of ingesta and,
in turn, the satiation process.
