[Role of disorders of calcium homeostasis in the development of ischemic contracture of the heart].
The development of ischemic contracture in rat was evaluated in relation to glycolytic production of ATP and Ca2+ homeostasis. When the rate of glycolysis was reduced by glycogen depletion (swimming at 33 degrees C for 2 h, administration of isoprenaline or heart perfusion with it), the rate of ischemic contracture development increased. Isoprenaline increased the development of contracture in a dose-dependent manner, and dexamethasone potentiated the effect of isoprenaline. The decrease in the intensity of ATP/P1 exchange, probably reflecting the intensity of glycolytic phosphorylation of ADP, which, in our conditions, arose from ATP hydrolyzed mostly by Ca2+-ATPase and Na, K-ATPase, correlated with the development of ischemic contracture. Experiments with the rapid equilibration of the extracellular compartment with Ca2+ in various concentrations in the presence or absence of verapamil suggest that the development of ischemic contracture depends on the rate of Ca2+ accumulation in myoplasm. This rate of Ca2+ accumulation correlates with the rate of glycogenolysis and glycolysis which seems to produce ATP for active transport of cations.
Kyrge
P K
PK
Vigel
E L
EL
Miannik
G N
GN
D000255:Adenosine Triphosphate / Q000172:deficiency; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003327:Coronary Disease / Q000209:etiology* / Q000378:metabolism; D006003:Glycogen / Q000172:deficiency; D006019:Glycolysis; D006706:Homeostasis; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D000255:Adenosine Triphosphate; D006003:Glycogen; D002118:Calcium
Znachenie narusheniĭ gomeostaza kal'tsiia v mekhanizme razvitiia ishemicheskoĭ kontraktury serdtsa.