[Intracellular localization of the processes of biosynthesis and degradation of NADP in skeletal muscle].

In studies on intracellular NADP localization the process of NADP biosynthesis was observed in mitochondria and hyaloplasm of rabbit sceletal muscle cells. This synthesis was not found in microsomal and nuclear fractions. The seasonal alterations in the NAD-kinase activity were established: in autumn and winter months NADP synthesis proceeded at the maximal rate in hyaloplasm; in sping months the higher specific activity was observed in mitochondrial fraction. The rate of NADP synthesis was 2-5 times lower in initial and reconstructed (hyaloplasm+cell organelles) homogenate then in hyaloplasm, among the enzymes, degrading the NADP molecule in sceletal muscle, the highest activity was exhibitel by nucleosidase, which was localized mainly in mitochondria and microsomes. Mechanisms for regulation of the rate of NADP synthesis and degradation in cytostructures of rabbit sceletal muscles are discussed.