Differential expression and regulation of somatostatin receptor
subtype 2 (sstr2) messenger rna in rat gastric antrum and corpus.
Sandvik, Arne K., Rod Dimaline, Eiliv Brenna, and Helge L. Waldum.
Physiological Laboratory and Department of Medicine, University of
Trondheim, N-7005 Trondheim, Norway, Physiological Laboratory,
University of Liverpool, P.O. Box 147, Crown Street, Liverpool L69
3BX, U.K.
APStracts 2:0066G, 1995.
Somatostatin modulates both endocrine and exocrine functions in the
gastric mucosa, where three of the five cloned somatostatin receptors
are present. This study examines changes in somatostatin receptor
(SSTR) mRNA abundance during fasting, feeding and profound acid
inhibition with omeprazole. Serum gastrin, and somatostatin and SSTR
mRNA abundances, were measured in antrum and corpus. In Northern
blots of corpus RNA the SSTR2 probe hybridized with two previously
reported species of mRNA (2.4 and 2.8 kb); in addition a weak
previously unreported 1.6 kb band was detected. In antrum the 1.6
band dominated. Fasting increased antral somatostatin mRNA from 100 +
8% to 161 + 24% and SSTR mRNA from 100 + 10% to 179 + 14% (p<0.05).
Omeprazole reduced antral somatostatin mRNA to 34 + 4% of control
(p<0.05) and elevated SSTR mRNA to 135 + 5% of control (p<0.01).
Omeprazole treatment reduced corpus somatostatin mRNA to 59 + 5%
(p<0.05), and elevated SSTR mRNA to 140 + 3% of control (p<0.01).
The results therefore indicate that a novel SSTR mRNA subtype exists
in the stomach, and predominates in the antrum. The abundance of this
SSTR mRNA is upregulated by both fasting and achlorhydria; conditions
that increase or decrease endogenous antral somatostatin,
respectively.
Received 28 November 1994; accepted in final form 13 April 1995.
APS Manuscript Number G466-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 April 1995.