The effects of univalent anions on catecholamine fluxes and adenosine triphosphatase activity in storage vesicles from the adrenal medulla.

1. Influx and efflux of catecholamine and adenosine triphosphatase activity were studied in storage vesicles of bovine adrenal medulla. 2. In the absence of ATP the influx of catecholamine was slow and was not influenced by various anions, whereas the efflux increased in the sequence of anions given by the lyotrophic series. 3. In the presence of ATP the efflux was enhanced compared with that in the absence of ATP; the anion-dependent sequence, however, in which the efflux increased was the same as in the absence of ATP. 4. The ATP-dependent catecholamine influx and the adenosine triphosphatase activity are correlated. The sequence in which anions affect adenosine triphosphatase activity and catecholamine influx, however, is completely different from the lyotrophic anion series. 5. No correlation was found between adenosine triphosphatase activity and the efflux of catecholamine.