CNS regulation of gastric and autonomic functions in dogs by gastrin-releasing peptide

1988 ◽  
Vol 255 (3) ◽  
pp. G298-G303
Author(s):  
H. J. Lenz

The central nervous system effects of canine gastrin-releasing peptide (GRP) were studied on gastric acid secretion, emptying, blood flow, and the autonomic nervous system in conscious dogs. GRP injected into the third cerebral ventricle significantly (P less than 0.01) increased plasma epinephrine but not norepinephrine concentrations. GRP (0.1-1.0 nmol/kg) significantly decreased gastric acid secretion stimulated by an 8% peptone meal, delayed gastric emptying of the liquid peptone meal, and increased left gastric artery flow. Ganglionic blockade, truncal vagotomy, or adrenalectomy did not abolish the inhibitory effect of GRP on gastric acid secretion. However, ganglionic blockade or vagotomy abolished the GRP-induced inhibition of gastric emptying, and ganglionic blockade or adrenalectomy abolished the GRP-induced increases in left gastric artery flow and plasma epinephrine concentrations. An intravenous infusion of epinephrine that produced similar plasma concentrations of epinephrine that were observed after cerebroventricular injection of GRP mimicked the increase in left gastric artery flow induced by GRP. It is concluded that 1) GRP acts within the central nervous system to activate the sympathoadrenal axis, 2) GRP inhibits gastric emptying of a liquid meal by a vagally dependent mechanism and enhances left gastric artery flow by the release of epinephrine from the adrenal medulla, and 3) the pathway(s) that mediate the GRP-induced inhibition of gastric acid in the dog remain unknown.

Endocrinology ◽  
2000 ◽  
Vol 141 (8) ◽  
pp. 2854-2860 ◽  
Author(s):  
Toshikatsu Okumura ◽  
Hiroto Yamada ◽  
Wataru Motomura ◽  
Yutaka Kohgo

Recent study has indicated that cocaine-amphetamine-regulated transcript (CART) is an anorectic chemical in the brain. In the present study, we examined the hypothesis that CART may act in the central nervous system to alter gastric function. Food consumption, gastric acid secretion, and gastric emptying were measured after injection of CART into the cerebrospinal fluid in 24-h fasted Sprague Dawley rats. Central injection of CART inhibited food intake, gastric acid secretion, and gastric emptying. In contrast, ip injection of CART failed to inhibit gastric acid secretion and gastric emptying, suggesting that CART acts in the brain to suppress gastric acid secretion and gastric emptying. In the vagotomized animals, centrally administered CART did inhibit pentagastrin-stimulated gastric acid secretion. The CART-induced acid inhibition was also observed in rats treated with indomethacin, a cyclooxygenase inhibitor. In contrast, pretreatment with central administration of a CRF receptor antagonist,α -helical CRF9–41, completely blocked the central CART-induced inhibition of gastric acid secretion. All these results suggest that CART acts in the brain to inhibit gastric function via brain CRF system. The vagal pathway and the prostaglandin system are not involved in the acid inhibition.


1989 ◽  
Vol 256 (1) ◽  
pp. G214-G219 ◽  
Author(s):  
G. Druge ◽  
A. Raedler ◽  
H. Greten ◽  
H. J. Lenz

The pathways involved in mediating the central nervous system actions of corticotropin-releasing factor (CRF) on gastric acid secretion were examined in conscious rats. CRF (0.1-2.0 nmol) given cerebroventricularly inhibited gastric acid secretion stimulated by pentagastrin (P less than 0.01). This effect was abolished by cerebroventricular but not intravenous administration of a specific CRF receptor antagonist, alpha-helical CRF-(9-41). Ganglionic blockade with chlorisondamine chloride, noradrenergic blockade with bretylium, or adrenalectomy abolished the gastric inhibitory action of CRF whereas truncal vagotomy or opiate blockade with naloxone did not. A vasopressin receptor antagonist significantly inhibited but did not abolish the gastric inhibitory action of CRF. An intravenous infusion of epinephrine that mimicked the epinephrine plasma concentrations which were observed after cerebroventricular administration of CRF did not alter pentagastrin-stimulated gastric acid secretion. These results indicate that CRF acts within the central nervous system to inhibit gastric acid secretion by a specific receptor-mediated event. Inhibition of gastric acid secretion by CRF in conscious rats is mediated by efferent fibers of the sympathetic nervous system and in part by a vasopressin-dependent pathway but not by the parasympathetic nervous system, adrenal epinephrine release, or opiate-sensitive pathways.


2001 ◽  
Vol 280 (3) ◽  
pp. 904-907 ◽  
Author(s):  
Yukari Date ◽  
Masamitsu Nakazato ◽  
Noboru Murakami ◽  
Masayasu Kojima ◽  
Kenji Kangawa ◽  
...  

1989 ◽  
Vol 34 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Roberto Corinaldesi ◽  
Vincenzo Stanghellini ◽  
Giovanni Francesco Paparo ◽  
Anna Paternic� ◽  
Anna Giulia Rusticali ◽  
...  

1999 ◽  
Vol 276 (2) ◽  
pp. G550-G555 ◽  
Author(s):  
Xiao-Tuan Zhao ◽  
John H. Walsh ◽  
Helen Wong ◽  
Lijie Wang ◽  
Henry C. Lin

Fat in small intestine decreases meal-stimulated gastric acid secretion and slows gastric emptying. CCK is a mediator of this inhibitory effect (an enterogastrone). Because intravenously administered peptide YY (PYY) inhibits acid secretion, endogenous PYY released by fat may also be an enterogastrone. Four dogs were equipped with gastric, duodenal, and midgut fistulas. PYY antibody (anti-PYY) at a dose of 0.5 mg/kg or CCK-A receptor antagonist (devazepide) at a dose of 0.1 mg/kg was administered alone or in combination 10 min before the proximal half of the gut was perfused with 60 mM oleate or buffer. Acid secretion and gastric emptying were measured. We found that 1) peptone-induced gastric acid secretion was inhibited by intestinal fat ( P < 0.0001), 2) inhibition of acid secretion by intestinal fat was reversed by CCK-A receptor antagonist ( P < 0.0001) but not by anti-PYY, and 3) slowing of gastric emptying by fat was reversed by CCK-A antagonist ( P< 0.05) but not by anti-PYY. We concluded that inhibition of peptone meal-induced gastric acid secretion and slowing of gastric emptying by intestinal fat depended on CCK but not on circulating PYY.


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