Calcium binding by cardiac relaxing system isolated from myopathic syrian hamsters (strains 14.6, 82.62 and 40.54)

Abstract

Cardiac relaxing system (CRS) was isolated from control (BIO-RB) and cardiomyopathic (BIO 14.6, BIO 82.62 and BIO 40.54) hamsters. Both dual-beam spectrophotometric and Millipore filter methods were employed to study calcium binding by CRS. The four groups (control and cardiomyopathic hamsters) were killed at three ages: Age I = 60 ± 9 days, Age II = 216 ± 7 days, and Age III = 262 ± 12 days. The latter two ages were in congestive heart failure. CRS isolated from Age I did not demonstrate diminished capacity or rate of calcium binding, whereas both Ages II and III revealed a decrease in rate and maximal capacity of calcium binding compared to controls. It is suggested that an aberration of intracellular calcium metabolism is characteristic of congestive heart failure associated with the cardiomyopathic process.