Adenosine triphosphate in the bovine chromaffin granule.
1. pH and potential gradients are generated across the membranes of chromaffin granule 'ghost' by incubating them with MgATP: the inside of the 'ghosts' is positive and acid with respect to the incubation medium. 2. The pH gradient is partially dissipated by inclusion of a substrate for the catecholamine pump, or a mitochondrial uncoupling agent, but is enhanced by reserpine. 3. An imposed pH gradient leads to amine uptake by the 'ghosts': a potential gradient leads to ATP uptake. Studies with inhibitors confirm that amine accumulation by chromaffin granules is dependent on the former, and that ATP uptake results from ATPase-induced potential difference generation. 4. ATP has two known roles in chromaffin granule structure: the first is as a substrate for a membrane-bound proton-translocating ATPase; the second is as a component of the intragranular catecholamine storage complex.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002837:Chromaffin Granules / Q000378:metabolism*; D002838:Chromaffin System / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008564:Membrane Potentials; D012701:Serotonin / Q000378:metabolism; D014475:Uncoupling Agents / Q000494:pharmacology
D002395:Catecholamines; D014475:Uncoupling Agents; D012701:Serotonin; D000255:Adenosine Triphosphate