Adenosine deaminase reduces hypoxic and hypercapnic dilatation of rat pial arterioles: evidence for mediation by adenosine.
Rat pial arteries were observed through a closed cranial window during hypercapnic and hypoxic episodes whilst the cerebral cortex was superfused at 37 degrees C first with artificial cerebrospinal fluid (CSF) and subsequently with adenosine deaminase (ADA, 0.5-2.0 U/ml) in CSF. The results indicate that ADA attenuated hypercapnic and hypoxic dilatatory arteriolar responses by 64% and 56% respectively. Recovery was obtained by superfusing with ADA-free CSF for 1 h. We conclude that adenosine is involved in hypercapnia- and hypoxia-evoked dilation of pial arteries.
Simpson
R E
RE
Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201.
Phillis
J W
JW
D000241:Adenosine / Q000502:physiology*; D000243:Adenosine Deaminase / Q000494:pharmacology*; D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D010841:Pia Mater / Q000098:blood supply*; D051381:Rats; D011919:Rats, Inbred Strains; D014664:Vasodilation / Q000187:drug effects*
D002245:Carbon Dioxide; D000243:Adenosine Deaminase; D000241:Adenosine; D010100:Oxygen