ATP-driven transport and accumulation of epinephrine in chromaffin granule membrane vesicles isolated from bovine adrenal medulla is inhibited by the proton ionophores carbonylcyanide p-trifluoromethoxyphenylhydrazone and nigericin, but not by valinomycin. Moreover, an artificially imposed pH gradient (interior acid) is able to drive this reserpine-sensitive transport system in the absence of ATP. Dicyclohexylcarbodiimide, an inactivator of the chromaffin granule membrane-bound ATPase, completely inhibits ATP-dependent epinephrine accumulation, but has much less effect when an imposed pH gradient is the driving force for epinephrine transport. The findings provide a strong indication that a pH gradient (interior acid) is the immediate driving force for epinephrine uptake in these storage granules and suggest that ATP-driven epinephrine transport is the result of two processes: (i) generation of a proton electrochemical gradient (interior acid and positive) by the membrane-bound, proton-translocating ATPase; and (ii) pH gradient-driven accumulation of the catecholamine.
Effect of external high potassium and pH on the uptake of choline in glial and neuronal cells in culture
Determination of catecholamine permeability coefficients for passive diffusion across phospholipid vesicle membranes
Reduction by reserpine of the accumulation of retrogradely transported [125I]nerve growth factor in sympathetic neurons
The fetal and neonatal brain protein neuronatin protects PC12 cells against certain types of toxic insult
Homology of a vesicular amine transporter to a gene conferring resistance to 1-methyl-4-phenylpyridinium
The molecular mechanism of "ecstasy" [3,4-methylenedioxy-methamphetamine (MDMA)]: serotonin transporters are targets for MDMA-induced serotonin release
The pharmacological profile of the vesicular monoamine transporter resembles that of multidrug transporters
Characterization of the monoamine uptake system in catecholamine storage vesicles isolated from a pheochromocytoma taken from a child
Impaired neurotransmitter uptake in PC12 cells overexpressing human Cu/Zn-superoxide dismutase--implication for gene dosage effects in Down syndrome
Amphetamine and other psychostimulants reduce pH gradients in midbrain dopaminergic neurons and chromaffin granules: a mechanism of action
Mechanisms of accumulation of tyramine, metaraminol, and isoproterenol in isolated chromaffin granules and ghosts
Effect of drugs on the ATP-induced and pH-gradient-driven monoamine transport by bovine chromaffin granules
Mechanism of lactose translocation in membrane vesicles from Escherichia coli. 2. Effect of imposed delata psi, delta pH, and Delta mu H+
Osmotic swelling allows fusion of sendai virions with membranes of desialyzed erythrocytes and chromaffin granules
The role of a transmembrane pH gradient in 5-hydroxy tryptamine uptake by synaptic vesicles from rat brain
Reserpine as a competitive and reversible inhibitor of the catecholamine transporter of bovine chromaffin granules
Net uptake of catecholamines into isolated chromaffin granules demonstrated by a novel polarographic technique
Determination of the proportion of sealed vesicles in a preparation of chromaffin granule membrane 'ghosts'
Both the transmembrane pH gradient and the membrane potential are important in the accumulation of amines by resealed chromaffin-granule 'ghosts'
The electrochemical gradient of protons and its relationship to active transport in Escherichia coli membrane vesicles
Active proton uptake by chromaffin granules: observation by amine distribution and phosphorus-31 nuclear magnetic resonance techniques
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