Cysteamine induces cholecystokinin release from the duodenum. Evidence for somatostatin as an inhibitory paracrine regulator of cholecystokinin secretion in the rat

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Gastroenterology; (USA)

OSTI ID:6073211

Abucham, J; Reichlin, S ^[1]

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1. Tufts-New England Medical Center, Boston, MA (USA)

To determine whether cholecystokinin secretion is regulated by endogenous somatostatin, somatostatin deficiency was induced in vivo with cysteamine (250 mg/kg body wt, IV) or anti-somatostatin antiserum in anaesthetized rats and in vitro with cysteamine (30 micrograms/mL) in a rat duodenum-incubation system. Cholecystokinin secretion was assessed in vivo by measuring amylase in duodenal perfusates collected at 10-minute intervals for 1 hour and in vitro by a carboxy-terminal radioimmunoassay. Cysteamine induced a marked decrease in duodenal immunoreactive somatostatin both in vivo (50%) and in vitro (60%). The rate of amylase secretion increased from 9.7 +/- 2.1 U (mean +/- SE) to 28.0 +/- 4.8 U at 20 minutes (P less than 0.001). The cholecystokinin-receptor antagonist CR-1392 abolished amylase response for 30 minutes, whereas the more potent antagonists Asperlicin (18.0 mg/kg body wt, IV) and L-364,718 (0.25 mg/kg body wt, IV) caused prolonged blockade. The rate of amylase secretion in gastrectomized animals increased from 7.2 +/- 2.0 U to 15.0 +/- 2.2 U 20 minutes after cysteamine administration (P less than 0.01), indicating that the effect was not due to the presence of gastrin. In vitro, cysteamine caused a nearly fourfold increase in cholecystokinin secretion compared with controls (63.1 +/- 4.9 vs. 15.2 +/- 3.7, respectively; P less than 0.001). In vivo immunoneutralization of circulating somatostatin with a high-affinity and high-capacity antiserum produced no significant change in the rate of amylase secretion. These results suggest that cholecystokinin secretion is tonically inhibited by somatostatin and that this effect is mediated by locally secreted (paracrine) but not by circulating somatostatin.

• OSTI ID: 6073211
• Journal Information: Gastroenterology; (USA), Vol. 99:6; ISSN 0016-5085
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
KININS
SECRETION
MEA
BIOCHEMICAL REACTION KINETICS
SOMATOSTATIN
AMYLASE
IN VITRO
IN VIVO
RADIOIMMUNOASSAY
RATS
RECEPTORS
AMINES
ANIMALS
BIOASSAY
DIAGNOSTIC TECHNIQUES
DRUGS
ENZYMES
GLYCOSYL HYDROLASES
HYDROLASES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
KINETICS
MAMMALS
MEMBRANE PROTEINS
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
RADIOPROTECTIVE SUBSTANCES
REACTION KINETICS
RODENTS
THIOLS
TRACER TECHNIQUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques