Gastric antisecretory effects of synthetic cannabinoids after central or peripheral administration in the rat.
Previous studies have revealed that cannabinoid (CB)-receptor agonists inhibit gastric acid secretion stimulated by indirectly acting agents, but not by histamine. Aiming to investigate whether central or peripheral mechanisms are involved, the effects of the synthetic CB-receptor agonists WIN55,212-2 and HU-210, administered either intracerebroventricularly (i.c.v.) or intravenously (i.v.) to the anaesthetized rat with lumen-perfused stomach, against gastric acid secretion induced by pentagastrin were tested. Injected i.c.v., both WIN55,212-2 (50 and 100 microg/kg) and HU-210 (25, 50 and 100 microg/kg) were ineffective on either basal secretion or acid output induced by pentagastrin (7.7 microg/kg, i.v.). By contrast, i.v. injections of WIN55,212-2 (100 and 1000 microg/kg) or HU-210 (10-100 microg/kg) significantly inhibited pentagastrin-induced acid secretion, maximal reductions being 75.70 and 82.24% for WIN55,212-2 and HU-210, respectively. The gastric antisecretory effect of HU-210 was prevented by administration of the selective CB(1)-receptor antagonist SR141716A (1000 microg/kg, i.v.). These results show that CB(1)-receptors mediating inhibition of gastric acid secretion in the rat are mainly peripherally located.
Adami
Maristella
M
Department of Human Anatomy, Pharmacology and Forensic Medicine, Section of Pharmacology, Medical Faculty, University of Parma, Via Volturno 39, I-43100 Parma, Italy.
Zamfirova
Rossitsa
R
Sotirov
Emil
E
Tashev
Roman
R
Dobrinova
Yordanka
Y
Todorov
Simeon
S
Coruzzi
Gabriella
G
D000704:Analysis of Variance; D000818:Animals; D019540:Area Under Curve; D048588:Benzoxazines; D002121:Calcium Channel Blockers / Q000008:administration & dosage; D002186:Cannabinoids / Q000138:chemical synthesis / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004333:Drug Administration Routes; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D007275:Injections, Intravenous / Q000379:methods; D007276:Injections, Intraventricular / Q000379:methods; D008297:Male; D009025:Morpholines / Q000008:administration & dosage; D009281:Naphthalenes / Q000008:administration & dosage; D010418:Pentagastrin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000187:drug effects*
D048588:Benzoxazines; D002121:Calcium Channel Blockers; D002186:Cannabinoids; D018691:Excitatory Amino Acid Antagonists; D009025:Morpholines; D009281:Naphthalenes; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D013759:Dronabinol; D010418:Pentagastrin; C062018:HU 211