Uptake of adenosine into cultured cerebral endothelium.

Adenosine uptake by cultured cerebral endothelium is a carrier-mediated process. The Km value for adenosine uptake is 5.0 microM and the vmax is 1.15 nmol/min/mg cell protein. The uptake system is inhibited by the adenosine analog 2-chloroadenosine at low adenosine concentrations. The results prove the existence of a nucleoside transport system associated with cerebral capillary endothelium.