title: [Stress-induced changes in the functioning of the Ca-transport system of the cardiac sarcoplasmic reticulum and its resistance to endogenous damaging factors].
abstract: The kinetic characteristics of a calcium transport by sarcoplasmic reticulum was measured in homogenate of rat heart by means of Ca-selective electrode in the presence of oxalte and azide. As a function of the increasing CaCl2 concentration, the rate of Ca2+ uptake demonstrate a linear (in the physiological concentration field) and saturable components. Prolonged immobilization was accompanied by a decrease in Ca-concentration dependence of Ca2+ uptake. Nonsignificant fall of Vm was accompanied by simultaneous decrease of KM by 30% after stress. Storage of heart homogenates revealed three-fold decrease of inactivation rate in the stress series. Initial concentration of free Ca2+ and its raise during storage was increased in heart homogenates, prepared after stress. The role of calcium pump resistance to endogenous damage factors in the stress-induced heart disturbance are discussed.
authors.forename: T G
authors.initials: TG
authors.lastname: Sazontova
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D002122:Calcium Chloride / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012149:Restraint, Physical; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D013315:Stress, Psychological / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D000255:Adenosine Triphosphate; D002122:Calcium Chloride; D002118:Calcium
vernacular_title: Stressindutsirovannye izmeneniia funktsionirovaniia Ca-transportiruiushcheĭ sistemy sarkoplazmaticheskogo retikuluma serdtsa i ee ustoĭchivost' k éndogennym povrezhdaiushchim faktoram.