Developmental changes in myocardial function have been described by a number of investigators. To further define the cellular basis for these changes, the present study was designed to characterize age-related changes in Ca2+ transport in sarcoplasmic reticulum (SR) vesicles isolated from six groups of sheep: group (Sp) I (100-105 days gestation), Gp II (128-132 days gestation), Gp III (postnatal, 0-3 days), Gp IV (4 wk), Gp V (8 wk), and Gp VI (maternal sheep). The maximal Ca2+ uptake for vesicles isolated from Gp I-V was significantly (p < 0.01) decreased as compared to that measured for Gp VI (maternal) vesicles. However, Ca2+-dependent ATP hydrolysis was decreased only in the fetal SR vesicles (Gp III). Thus, decreased ATP hydrolysis only partially explained the decreased Ca2+ uptake. In contrast, calculation of apparent Ca2+ pump coupling ratios (mol of Ca2+ trans-ported/mol of ATP hydrolyzed) showed that there was a marked increase in the coupling of Ca2+ transport to ATP hydrolysis during maturation of the heart. Inasmuch as the contractile state of the heart depends on precise regulation of Ca2+ concentration by the SR, these age-related changes in SR function may contribute to developmental changes in myocardial function. © 1988 International Pediatrics Research Foundation, Inc.
CITATION STYLE
Mahony, L. (1988). Maturation of calcium transport in cardiac sarcoplasmic reticulum. Pediatric Research, 24(5), 639–643. https://doi.org/10.1203/00006450-198811000-00020
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