[Effect of ionophore Brx537A on catecholamine liberation from chromaffin granules]

In the present paper the author studies the action of bromine analog of carboxil ionophore X-537A on the transport mechanism of catecholamines from isolated chromaffine granules. The transfer of catecholamines through artificial membranes was explained by the ability of ionophore and its bromine derivative to raise their permeability in organic solvents and to transfer them through the organic phase. A model for the action of Brx 537A on isolated granules was constructed. It was established that the ionophorex acted as a carrier, enhancing the transport of the protonated form of catecholamines, which in general diffuse slightly. The model transport system could explain the differences in releasing catecholamines and the favourable effect of cations in the transport through the membranes.