Two different ATP-dependent mechanisms for calcium uptake into chromaffin granules and mitochondria

摘要: The uptake of 45Ca2+ and [3H](−)noradrenaline into chromaffin granules as well the mitochondria bovine adrenal medulla was studied in presence various anions inhibitors respiratory chain to obtain further evidence for an ATP-stimulated granules. This is: (1) During incubation rate higher nitrate than orthophosphate; inverse relationship found mitochondria. In lower those which do not penetrate membrane (2) prolonged lyotropic lysis high density (in buoyancy with 2.0 M sucrose after centrifugation at 170,000g · 60 min) accompanied by a very pronounced reduction content density, while only moderately reduced. (3) ATP gradient fraction less sensitive antimycin A (1·10−6 M) rotenone (2.5·10−5 Rotenone inhibited sulphate both mechanisms were equally rotenone.