Effects of 4-h ischemia and 1-h reperfusion on rat muscle sarcoplasmic reticulum function

• Published in: American journal of physiology: endocrinology and metabolism 2001-10, Vol.281 (4), p.E867-E877, Article E867
• Main Authors: Tupling, R, Green, H, Senisterra, G, Lepock, J, McKee, N
• Format: Article
• Language: English
• Subjects: Animals; Biological Transport; Calcium - metabolism; Calcium-Transporting ATPases - metabolism; Creatine - metabolism; Female; Glycogen - metabolism; Hindlimb; Ischemia - physiopathology; Kinetics; Lactates - metabolism; Muscle Contraction; Muscle, Skeletal - blood supply; Muscle, Skeletal - physiology; Phosphates - metabolism; Phosphocreatine - metabolism; Rats; Rats, Sprague-Dawley; Reference Values; Reperfusion; Sarcoplasmic Reticulum - physiology; Time Factors
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.2001.281.4.e867

Departments of 1  Kinesiology and 2  Physics, University of Waterloo, Waterloo N2L 3G1; and 3  Department of Surgery, University of Toronto, Toronto, Ontario M5S 1A8, Canada To investigate the hypothesis that ischemia and reperfusion would impair sarcoplasmic reticulum (SR) Ca 2+ regulation in skeletal muscle, Sprague-Dawley rats ( n  = 20) weighing 290 ± 3.5 g were randomly assigned to either a control control (CC) group, in which only the effects of anesthetization were studied, or to a group in which the muscles in one hindlimb were made ischemic for 4 h and allowed to recover for 1 h (I). The nonischemic, contralateral muscles served as control (C). Measurements of Ca 2+ -ATPase properties in homogenates and SR vesicles, in mixed gastrocnemius and tibialis anterior muscles, indicated no differences between groups on maximal activity, the Hill coefficient, and Ca 50 , defined as the Ca 2+ concentration needed to elicit 50% of maximal activity. In homogenates, Ca 2+ uptake was lower ( P