title: [Nitric oxide as the regulator of intracellular homeostasis in the uterus myocytes].
abstract: The published data on the mechanisms and regulation of active and passive Ca2+ transport in the myometrium have been analyzed. Particular attention is paid to the cGMP-dependent and independent pathways of action of nitric oxide or its derivatives on intracellular Ca2+ homeostasis of uterine smooth muscle and its contractile activity. Information on the effect of nitric oxide on Ca2+ -transport systems of other types of smooth muscles is provided in a comparative aspect. Based on own experimental results and literature data a scheme of NO action in the myometrium is suggested in which nitric oxide or its derivatives cause Ca2+ -dependent polarization of the sarcolemma. In accordance with our results, this effect may be based on the increase of sarcolemma Ca2+ permeability under the influence of NO or its derivatives and the stimulation of at least the initial passive transport of the cation in the myocytes mediated by dihydropyridine-sensitive channels. Additional factors that contribute to the polarization of the membrane are the increase of protons transport from the muscle cells and stimulation of Na+, K+ -ATPase. Acting on the sarcoplasmic reticulum, nitrosactive compounds activate the inclusion of calcium in this compartment and inhibit Ca2+ -induced release of the cation. The latter effects are able to provide compensation for NO-induced Ca2+ increase in myocytes and supress the electromechanical coupling at Ca2+ release from the reticulum. NO-derivates also inhibit a key link in the smooth muscle contractile act--the formation of the Ca2+ -calmodulin complex.
authors.forename: Iu V
authors.initials: IuV
authors.lastname: Danylovich
mesh_terms: D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D032342:Muscle Cells / Q000166:cytology / Q000378:metabolism*; D009119:Muscle Contraction / Q000502:physiology; D009215:Myometrium / Q000166:cytology / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D012508:Sarcolemma / Q000378:metabolism
chemical_list: D015220:Calcium Channels; D002147:Calmodulin; D009569:Nitric Oxide; D006152:Cyclic GMP; D002118:Calcium