[Effect of cholesterol on the cooperativeness of the Ca-ATPase of the sarcoplasmic reticulum in rabbit skeletal muscle].
Cooperative properties of Ca-ATPase of the sarcoplasmic reticulum (SR) of rabbit skeletal muscles were examined in health and hypercholesterolemia. As the concentration of ATP was raised (from 50-100 microM to 5 mM) the Hill ratio (Nh) for ATP increased from 0.4 to 3.2. It is assumed that increased cooperative interaction between Ca-ATPase polymers led to a rise in the efficacy of Ca-pump work. Under the conditions described the Nh for UTP increased from 0.43 to 1.0. During hypercholesterolemia (1 g/kg cholesterol for 1, 3 and 6 months), the maximal values of the Nh for ATP did not exceed 2.0, whereas those for UTP 1.0.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D006937:Hypercholesterolemia / Q000201:enzymology; D008297:Male; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013379:Substrate Specificity; D013997:Time Factors; D014544:Uridine Triphosphate / Q000378:metabolism
D002791:Cholesterol, Dietary; D000255:Adenosine Triphosphate; D002784:Cholesterol; D000252:Calcium-Transporting ATPases; D014544:Uridine Triphosphate
Vliianie kholesterina na kooperativnost' Ca-ATFazy sarkoplazmaticheskogo retikulma skeletnykh myshts krolika.