AJP - Gastrointestinal and Liver Physiology, Vol 270, Issue 1 220-G224, Copyright © 1996 by American Physiological Society
Glycine-extended gastrin potentiates gastrin-stimulated gastric acid secretion in rats
S. Higashide, G. Gomez, G. H. Greeley Jr, C. M. Townsend Jr and J. C. Thompson
Department of Surgery, University of Texas Medical Branch, Galveston 77555-0725, USA.
The purpose of this study was to examine whether an intermediate form of
amidated gastrin, glycine-extended gastrin (Gly-G), can stimulate gastric
acid secretion in conscious rats prepared with gastric fistulas.
Intravenous administration of Gly-G (20 nmol.kg-1.h-1) alone for 2 h did
not stimulate gastric acid secretion; however, administration of Gly-G (20
nmol.kg-1.h-1) in combination with a bolus administration of gastrin (9.5
nmol/kg) potentiated acid secretion significantly. Gastric acid secretion
in response to gastrin alone and gastrin plus Gly-G (2 nmol.kg-1.h-1) was
109.1 +/- 21.6 and 170.1 +/- 27.7 mueq.kg-1.h-1, respectively (P <
0.05). Gastric acid secretion in response to gastrin alone and gastrin plus
Gly-G (20 nmol.kg-1.h-1) was 84.8 +/- 17.5 and 164.1 +/- 29.3
mueq.kg-1.h-1, respectively (P < 0.05). Intravenous administration of
Gly-G (20 nmol.kg-1.h-1) failed to increase histamine (1 mg/kg)-stimulated
acid output. These results demonstrate that Gly-G can selectively
potentiate the stimulatory effect of gastrin on acid secretion in rats and
that the unprocessed form of gastrin, Gly-G, can exert a biological effect
in the stomach.
