Vol. 284, Issue 4, G638-G645, April 2003
Gastric atrial natriuretic peptide regulates endocrine
secretion in antrum and fundus of human and rat stomach
W. R.
Gower Jr1,
S.
Premaratne2,
R. W.
McCuen2,
A.
Arimura3,
Q.
McAfee1, and
M. L.
Schubert2
1 Department of Surgery, University of South Florida
and James A. Haley Veterans Affairs Medical Center, Tampa, Florida
33612; 2 Department of Medicine, Medical College of
Virginia/Virginia Commonwealth University and McGuire Veterans Affairs
Medical Center, Richmond, Virginia 23249; and
3 Department of Medicine, Tulane University, Belle
Chase, Louisiana 70037
Atrial natriuretic peptide (ANP) is
present in gastric mucosa and preferentially binds to two subtypes of
natriuretic peptide receptors (NPR), NPR-A and NPR-C. The present study
examines the role of endogenous ANP in regulating endocrine secretion
in rat and human stomachs. NPR-A protein expression and transcripts
were identified in rat antral and fundic mucosa by Western blot and RT-PCR. In superfused rat and human antral and fundic segments, ANP
(0.1 pM to 0.1 µM) caused a concentration-dependent increase in
somatostatin secretion. In antrum, this was accompanied by a decrease
in gastrin, and in fundus, this was accompanied by a decrease in
histamine secretion. Changes in gastrin and histamine secretion
reflected changes in somatostatin secretion and were abolished by
somatostatin antibody. The NPR-A receptor antagonist anantin
1) inhibited basal somatostatin secretion and 2)
abolished the somatostatin, gastrin, and histamine responses to ANP. We conclude that endogenous ANP, acting via the NPR-A receptor, stimulates somatostatin secretion from both antrum and fundus of rat and human
stomach. Stimulation of somatostatin secretion is coupled to inhibition
of gastrin secretion in the antrum and inhibition of histamine
secretion in the fundus.
somatostatin; gastrin; histamine; atrial natriuretic factor; natriuretic peptide receptor; hormone; peptide; guanylyl cyclase-A
