EFFECTS OF CYCLIC-AMP AND OF PROTEIN-KINASE ON THE CALCIUM-UPTAKE BY VARIOUS TRACHEAL SMOOTH-MUSCLE ORGANELLES

Abstract

The role of cyclic[c]AMP in the regulation of smooth muscle tone is not understood. The effects of cAMP and of protein kinase on the uptake of Ca by microsomal, plasma and mitochondrial preparations obtained from bovine tracheal smooth muscle were examined. cAMP and protein kinase had only a slight and variable effect on the uptake of Ca by microsomes and no effect on the uptake of Ca by the plasma membrane or the mitochondria. These findings do not indicate a role of cAMP and protein kinase in the control of the uptake of Ca by the subcellular organelles of tracheal smooth muscle.