Central effect of melatonin against stress-induced gastric ulcers in rats.
We investigated the role of melatonin in the induction of gastric lesions induced by water immersion restraint stress or centrally administered thyrotropin-releasing hormone (TRH). Melatonin (0.1-1 ng) injected intracisternally (i.c) 30 min prior to stress dose-dependently inhibited the induction of gastric lesions by water immersion restraint stress, while 100 micrograms/kg, i.p. failed to protect the gastric mucosa. Preadministration of melatonin (1 ng, i.c.) significantly reduced (83%) the severity of gastric lesions induced by a TRH analogue (500 ng, i.c.). Serum melatonin concentrations 30 min after administration of 1 ng melatonin i.c. did not differ from those of rats receiving i.c. vehicle. These results suggest that melatonin plays a protective, anti-stress, role in the gastric mucosa via a mechanism involving the central nervous system.
Kato
K
K
Third Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan.
Murai
I
I
Asai
S
S
Komuro
S
S
Matsuno
Y
Y
Matsukawa
Y
Y
Kurosaka
H
H
Iwasaki
A
A
Ishikawa
K
K
Arakawa
Y
Y
D000818:Animals; D002490:Central Nervous System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000187:drug effects*; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D010437:Peptic Ulcer / Q000188:drug therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000503:physiopathology*
D008550:Melatonin