A central role for adenosine in the hypotension elicited by hypoxia in anesthetized rats.
Brief inhalation of an oxygen-deficient (5%) gas mixture evoked a rapidly developing, profound hypotension in anesthetized rats. Recovery upon reoxygenation was also rapid. A potential involvement of adenosine in the genesis of this hypotension was evaluated with various peripherally administered adenosine antagonists. Caffeine (10 mg/kg), which readily crosses the blood-brain barrier, significantly attenuated the hypoxia-evoked hypotension. 8-p-Sulphophenyltheophylline and xanthine amine congener, which do not readily penetrate the blood-brain barrier, had little effect on the magnitude of the hypotension. The data suggests that hypoxia-elicited hypotension in anesthetized rats results from the activation of central adenosine receptors.
Simpson
L
L
Department of Physiology, School of Medicine, Wayne State University, Detroit, MI 48201.
Barraco
R A
RA
Phillis
J W
JW
D000241:Adenosine / Q000037:antagonists & inhibitors / Q000502:physiology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D007022:Hypotension / Q000209:etiology / Q000378:metabolism*; D000860:Hypoxia / Q000150:complications*; D008297:Male; D051381:Rats; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D014970:Xanthines; D002110:Caffeine; C031433:8-(4-sulfophenyl)theophylline; C051869:8-(4-((2-aminoethyl)aminocarbonylmethyloxy)phenyl)-1,3-dipropylxanthine; D013806:Theophylline; D000241:Adenosine