Adenosine transporters in chromaffin cells. Quantification by dipyridamol monoacetate.
Chromaffin cells from bovine adrenal medulla are a useful model to approach adenosine transport and metabolism in neural cells. Dipyridamol has been shown to be an adenosine transport inhibitor with high affinity. To quantify the adenosine transporters a labelled dipyridamol analogue, [14C]dipyridamol acetate, was synthesized. This compound had a Ki = 5.3 +/- 0.43 nM according to the Dixon method, and 4.58 +/- 0.46 nM when the receptor number molarity was taken into account showing, like dipyridamol, a non-competitive mechanism. The high-affinity receptors present in chromaffin cells showed a Kd = 6.8 +/- 0.8 nM and the receptor number was 630 000 +/- 40 000 per cell.
Torres
M
M
Molina
P
P
Miras-Portugal
M T
MT
D000241:Adenosine / Q000378:metabolism*; D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000032:analysis* / Q000378:metabolism; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D002838:Chromaffin System / Q000378:metabolism*; D004176:Dipyridamole / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology; D013055:Spectrophotometry, Infrared
D002352:Carrier Proteins; C048992:dipyridamole monoacetate; D004176:Dipyridamole; D000241:Adenosine