Gastric protection by alpha-melanocyte-stimulating hormone against ethanol in rats: involvement of somatostatin.
The proopiomelanocortin-derived tridecapeptide alpha-melanocyte-stimulating hormone (alpha-MSH) is a neuropeptide that exerts broad anti-inflammatory actions in mammals. This study aimed to investigate the effect of alpha-MSH on ethanol-induced gastric ulcer in rats and to evaluate the involvement of endogenous somatostatin in the actions of the peptide. The rats received 1 mL 75% ethanol or saline orally. alpha-MSH was given (25 micro g/rat; i.p.) alone or following the somatostatin antagonist cyclo-(7-aminoheptanoyl-PH-E-d-Trp-Lys-THR) (10 microM/kg; i.p.) administration. Gastric lesions were scored macroscopically and microscopically following decapitation at 30 min after ethanol challenge. Gastric malondialdehyde (MDA) level, myeloperoxidase (MPO) activity and mast cell counts were assessed. Ethanol-induced gastric hemorrhagic lesions were characterized by increased gastric MDA level, MPO activity and mast cell counts. alpha-MSH treatment decreased the extent of tissue injury and reversed tissue MDA level, MPO activity and mast cell counts. The effect of the peptide on the severity of gastric lesions, MDA level and MPO activity was reversed by the somatostatin antagonist. In conclusion, alpha-MSH is beneficial in a rat model of gastric ulcer via mechanisms which partly involve the endogenous somatostatin.
Jahovic
Nermina
N
Marmara University, School of Medicine, Department of Physiology, Haydarpasa, 34668, Istanbul, Turkey.
Erkanli
Gözde
G
Işeri
Sevgin
S
Arbak
Serap
S
Alican
Inci
I
D000818:Animals; D002452:Cell Count; D002492:Central Nervous System Depressants / Q000009:adverse effects*; D019610:Cytoprotection / Q000187:drug effects; D004195:Disease Models, Animal; D004336:Drug Antagonism; D000431:Ethanol / Q000009:adverse effects*; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006727:Hormone Antagonists / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008407:Mast Cells / Q000473:pathology; D010438:Peptic Ulcer Hemorrhage / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013004:Somatostatin / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D013270:Stomach / Q000187:drug effects / Q000473:pathology; D013276:Stomach Ulcer / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000521:alpha-MSH / Q000494:pharmacology*
D002492:Central Nervous System Depressants; D006727:Hormone Antagonists; D006728:Hormones; D000431:Ethanol; D008315:Malondialdehyde; D013004:Somatostatin; D000521:alpha-MSH; C043820:cyclo(7-aminoheptanoylphenylalanyl-tryptophyl-lysyl-benzylthreonyl); D009195:Peroxidase