title: [ATPase activity and ATP-dependent accumulation of Ca2+ in skeletal muscle nuclei. Effects of denervation and electric stimulation].
abstract: The dependence of the ATPase activity of skeletal muscle nuclei on divalent cations was studied. An addition of Ca2+ significantly increased the activity of nuclear ATPase. Mg2+ exerted an activating effect in the presence of 10(-5) M Ca2+ and an inhibiting effect in the presence of 2 x 10(-3) M Ca2+. Predominant localization of Ca-ATPase in the nucleoli and in the internal nuclear envelope was demonstrated by an electron microscopic histochemical technique. ATP increased the uptake of 45Ca by muscle nuclei; the optimal conditions for this incorporation were established. The changes in Ca-ATPase activities and in the ATP-dependent uptake of 45Ca induced by denervation and electric stimulation were found to be synchronous and unidirectional.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002466:Cell Nucleolus / Q000201:enzymology; D002467:Cell Nucleus / Q000201:enzymology* / Q000648:ultrastructure; D004558:Electric Stimulation; D004789:Enzyme Activation; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008854:Microscopy, Electron; D009121:Muscle Denervation; D009132:Muscles / Q000201:enzymology / Q000502:physiology*; D011817:Rabbits
chemical_list: D000251:Adenosine Triphosphatases; D000252:Calcium-Transporting ATPases; D008274:Magnesium; D002118:Calcium
vernacular_title: Issledovanie ATPaznoĭ aktivnosti i ATP-zavisimoĭ akkumuliatsii Ca2+ iadrami skeletnykh myshts. Effekty denervatsii i élektricheskoĭ stimuliatsii.