Adenosine release in morphine-induced hypotension in rats.
1. Following intravenous administration of morphine.HCl a reduction in mean arterial blood pressure (MABP) was produced, quaternary morphine analogue was ineffective. 2. Theophylline and 8-phenyltheophylline administration reduced morphine-induced hypotension. 3. A2 adenosine receptor agonist caused an hypotension while A1 adenosine receptor agonist was ineffective. 4. L-NG-Mono-methylarginine administration reduced the hypotensive effect of exogenous A2 agonist while it was ineffective on morphine-induced hypotension. 5. Morphine-induced hypotension was increased by pretreatment with dipyridamole, whereas tetrabenazine abolished it. 6. The present study is consistent with previous reports on the central hypotensive action of morphine and propose a role for adenosine release in morphine-induced hypotension.
Calignano
A
A
Department of Experimental Pharmacology, University of Naples Federico II, Italy.
Persico
P
P
Mancuso
F
F
Sorrentino
L
L
D015762:2-Chloroadenosine / Q000494:pharmacology; D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D004176:Dipyridamole / Q000494:pharmacology; D007022:Hypotension / Q000139:chemically induced* / Q000378:metabolism; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013747:Tetrabenazine / Q000494:pharmacology; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology; D019323:omega-N-Methylarginine
D015762:2-Chloroadenosine; D019323:omega-N-Methylarginine; D004176:Dipyridamole; D009020:Morphine; D001120:Arginine; D013806:Theophylline; C028322:8-phenyltheophylline; D000241:Adenosine; D013747:Tetrabenazine