Central action of somatostatin analog, SMS 201-995, to stimulate gastric acid secretion in rats.
The effects of intracisternal and intravenous injections of the somatostatin analog, SMS 201-995, on gastric acid secretion were investigated in rats with pylorus ligation or gastric cannula. Intracisternal injection of SMS 201-995 induced a dose-related (0.1-0.3 microgram) and long-lasting stimulation of gastric acid output with a peak response at 3 h postinjection in conscious, pylorus-ligated rats. Intracisternal SMS 201-995 increased histamine levels in the portal blood, whereas plasma gastrin levels were not modified. Atropine, cimetidine and adrenalectomy abolished the stimulatory effect of intracisternal SMS 201-995 (0.3 microgram). SMS 201-995 (0.03 microgram), microinjected unilaterally into the dorsal vagal complex, increased gastric acid output in urethane anesthetized rats. SMS 201-995, injected intravenously at 0.5 microgram, did not alter gastric secretion, whereas higher doses (5-20 micrograms) resulted in a dose-related inhibition of gastric acid secretion in conscious pylorus-ligated rats. These data indicate that SMS 201-995, a selective ligand for somatostatin-1 receptor subtype, induces a centrally mediated stimulatory effect on gastric acid secretion in rats. The central action involves the parasympathetic system, muscarinic and H2 receptors as well as adrenal-dependent pathways.
Center for Ulcer Research and Education, Veterans Administration Medical Center, Los Angeles, CA.
M
M
Yoneda
H
H
Raybould
Y
Y
Taché
D000311:Adrenal Glands / Q000502:physiology; D000315:Adrenalectomy; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002927:Cimetidine / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D006632:Histamine / Q000097:blood; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects; D015282:Octreotide / Q000008:administration & dosage*; D051381:Rats; D011919:Rats, Inbred Strains
D001285:Atropine; D002927:Cimetidine; D006632:Histamine; D015282:Octreotide