Circulating somatostatin-28 is not a physiologic regulator of gastric acid production in man.
Studies were designed to establish the acid inhibitory potency and plasma kinetics of somatostatin-28 (S-28) in humans and to determine whether the amount of S-28 released into the circulation after a meal is sufficient to regulate gastric acid secretion. A liquid meal induced a significant increase of S-28 (P < 0.01) whereas S-14 levels did not change. Postprandial S-28 concentrations were then mimicked by exogenous infusions and tested on basal and pentagastrin-stimulated gastric acid secretion. Expressed in terms of circulating plasma concentrations measured by specific radioimmunoassays, S-14 was 10 times more potent than S-28 in inhibiting gastric acid production. The plasma half-life of S-28 (1.86 min) was longer than that of S-14 (1.00 min) due to a slower plasma clearance rate. S-28 did neither affect basal and stimulated gastric acid secretion nor postprandial intragastric acidity. These studies suggest that postprandial plasma concentrations of S-28 are unlikely to regulate gastric acid secretion in man. They also show that S-28 is several times less potent than S-14 with respect to inhibition of gastric acid output.
Hildebrand
P
P
Division of Gastroenterology, University Hospital, Basel, Switzerland.
Ensinck
J W
JW
Buettiker
J
J
Drewe
J
J
Burckhardt
B
B
Gyr
K
K
Beglinger
C
C
D000328:Adult; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000502:physiology; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D006801:Humans; D007262:Infusions, Intravenous; D007700:Kinetics; D008297:Male; D011498:Protein Precursors / Q000008:administration & dosage / Q000097:blood / Q000502:physiology*; D013004:Somatostatin / Q000008:administration & dosage / Q000097:blood / Q000502:physiology*; D053561:Somatostatin-28
D011498:Protein Precursors; D013004:Somatostatin; D053561:Somatostatin-28