Calcium accumulation by isolated sarcoplasmic reticulum of skeletal muscle during development in tissue culture

✍ Scribed by John W. Lough; Mark L. Entman; Edward H. Bossen; James L. Hansen

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 439 KB
• Volume: 80
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040800313

✦ Synopsis

The calcium uptake and ATPase activities of isolated sarcoplasmic reticulum were studied during the first six days of chick skeletal musclc maturation in tissue culture. Statistically significant increases in these activities were observed between the second and the sixth day of maturation. Increases in oxalate-dependent calcium uptake were demonstrated at concentrations of 2.5 X 1 0 -5 M calcium and 1 0 -4 M calcium. Calcium-binding determinations conducted in the absence of oxalate displayed changes manifested by an increase at day 5 followed by a significant decrease at day 6. Increases in total ATPase activity during maturation paralleled the sequential increases in calcium uptake. Calcium-stimulated ATPase activity, however, did not change significantly during periods of marked increase in calcium uptake, suggesting that these activities are dissociated during development of the sarccplasmic reticulum. These data demonstrate that calcium uptake and total ATPase activity increase during muscle maturation in tissue culture and that these activities are present prior to spontaneous contractions.