Somatostatin-induced gastric protection against ethanol: involvement of nitric oxide and effects on gastric mucosal blood flow.
OBJECTIVE
The mechanisms of somatostatin-mediated gastroprotection are not fully understood. Aims of this study were to determine in the rat the role of nitric oxide (NO) in somatostatin-induced effects on gastric mucosal protection and blood flow (GMBF) in the absence and in the presence of intraluminal ethanol.


METHODS
Ethanol (70% v/v)-induced gastric mucosal injury after orogastric dosing was quantitated at 30 min and GMBF determined in an ex vivo gastric chamber preparation.


RESULTS
Somatostatin (4 microg/kg; i.p.) protection against ethanol-induced ulceration was prevented by the NO inhibitor L-NNA and restored by L-arginine, but not D-arginine. Somatostatin (1-8 microg/kg; i.p.) did not effect basal GMBF. The gastroprotective dose of somatostatin (4 microg/kg; i.p.) prevented the decrease in GMBF caused by ethanol. L-NNA reversed this vascular effect of somatostatin.


CONCLUSIONS
Somatostatin-induced gastroprotection and restoration of GMBF during ethanol exposure involve mechanisms which are dependent on NO generation.
Ancha
Hari
H
Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA.
Ojeas
Harry
H
Tedesco
Dustin
D
Ward
Angela
A
Harty
Richard F
RF
D000284:Administration, Oral; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001783:Blood Flow Velocity / Q000187:drug effects; D015740:Calcitonin Gene-Related Peptide / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000008:administration & dosage / Q000633:toxicity*; D005753:Gastric Mucosa / Q000098:blood supply* / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013004:Somatostatin / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D019335:Nitroarginine; D009569:Nitric Oxide; D000431:Ethanol; D013004:Somatostatin; D001120:Arginine; D015740:Calcitonin Gene-Related Peptide