Effects of adenosine on gastric and cardiovascular systems, and ethanol ulceration in male and female rats.
The time course of the effects of adenosine, a vasodilator, on the ulcerogenicity of ethanol was studied in male and female rats. Gastric secretory function and mucosal blood flow (GMBF), systemic blood pressure and heart rate were monitored during the 90-min experimental period. In the male rats, adenosine 7.5 mg/kg s.c. (injected at 30 min) increased the GMBF at 45 min and depressed it at 75 min. The mean blood pressure was decreased at 45 min and steadily recovered thereafter; the heart rate was unaffected throughout the experimental period. The gastric secretory volume was elevated at 60 min, with a significant drop in gastric acid output at the same time. Ethanol administration from 45 to 90 min produced haemorrhagic lesions in the glandular mucosa. The severity of gastric damage was markedly reduced by adenosine at 45 and 60 min when the GMBF and the secretory volume were increased respectively, but severity was increased at 75 min while the GMBF was significantly reduced. In the female rats, adenosine had no effect on the secretory function but still had a depressive action on GMBF at the 75th min. In these animals, adenosine exacerbated the gastric injury at 60 and 75 min. The blood pressure was also decreased at 45 min. In conclusion, adenosine produces a different pattern of effects on the ulcerogenic action of ethanol in male and in female rats. These differential effects depend on the states of GMBF and gastric secretory volume but not on the changes of systemic blood pressure and gastric acid secretion.
Cho
C H
CH
Department of Pharmacology, Faculty of Medicine, University of Hong Kong.
Liao
N X
NX
Liu
X G
XG
Hui
W M
WM
Luk
C T
CT
Lam
S K
SK
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D000431:Ethanol / Q000097:blood / Q000633:toxicity*; D005260:Female; D005750:Gastric Juice / Q000378:metabolism; D005753:Gastric Mucosa / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D007773:Lactates / Q000097:blood; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D012737:Sex Factors; D013270:Stomach / Q000187:drug effects*; D013276:Stomach Ulcer / Q000139:chemically induced / Q000517:prevention & control*
D000897:Anti-Ulcer Agents; D007773:Lactates; D000431:Ethanol; D000241:Adenosine