Uptake of adenosine by isolated rat brain capillaries.
Adenosine uptake by isolated rat brain capillaries is a carrier-mediated, temperature- and pH-sensitive process. The Km value for adenosine uptake is 4.74 microM and the Vmax is 21.7 picomol/mg protein/10 min. This is a high-affinity uptake system that can be cross-inhibited by several nucleosides and by the adenosine analogs tubercidin and 5'-deoxyadenosine. The uptake is very sensitive to inhibition by papaverine, hexobendine, and dipyridamole. These results confirm the existence of a nucleoside transport system associated with the blood-brain barrier observed during in vivo studies.
D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002196:Capillaries / Q000378:metabolism; D002560:Cerebrovascular Circulation; D003839:Deoxyadenosines / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D010208:Papaverine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012263:Ribonucleosides / Q000494:pharmacology; D014372:Tubercidin / Q000494:pharmacology
D003839:Deoxyadenosines; D012263:Ribonucleosides; C033714:5'-deoxyadenosine; D010208:Papaverine; D000241:Adenosine; D014372:Tubercidin