Adenine nucleotide and phosphoenolpyruvate transport by bovine chromaffin granule "ghosts".
Purified bovine adrenal chromaffin granule "ghosts" (resealed membranes) accumulate nucleotides and phosphoenolpyruvate in a temperature-dependent process. Equilibration takes several hours, the compounds being accumulated to not more than twice their concentration in the medium. This uptake occurs primarily by a non-saturable diffusion process, and rates and extents show little dependence on membrane energization. Uptake rates are inhibited less than 50% by compounds that discharge the "ghost" membrane potential, or by atractylate or low concentrations of Cibacron Blue. The data gave little support to the theory that chromaffin granules have a membrane potential-dependent adenine nucleotide transport process and that nucleotides are in equilibrium with the positive-inside potential across the granule membrane.
D000227:Adenine Nucleotides / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D002417:Cattle; D002837:Chromaffin Granules / Q000378:metabolism*; D002838:Chromaffin System / Q000378:metabolism*; D004734:Energy Metabolism; D066298:In Vitro Techniques; D008564:Membrane Potentials; D010728:Phosphoenolpyruvate / Q000378:metabolism*
D000227:Adenine Nucleotides; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D010728:Phosphoenolpyruvate; D000255:Adenosine Triphosphate