[Study of mitochondrial permeability for labeled cAMP].

Incubation of rat liver mitochondria with 3H-and 14C-cAMP under the conditions which are conducive to the activation of mitochondrial respiration by cAMP resulted in the penetration of cAMP into the mitochondria. Subfractionation of mitochondria was made with the use of digitonin and 0.1% Triton X-100. cAMP was incorporated into all the fractions investigated. A close correlation (r = +0.97) between 3H- and 14C-labelling of the mitochondria and submitochondrial fractions was found thus showing that the label was not only diluted but also accumulated by the mitochondria.