Development of sarcoplasmic reticulum in cultured chicken muscle.

摘要: The development of sarcoplasmic reticulum membranes was studied in vivo and tissue culture chicken pectoralis muscle cells. concentration the calcium- magnesium-activated ATPase measured by selective labeling enzyme with [32P]ATP whole homogenates found to increase developing from 0.01 nmol/mg protein 12-day embryos 0.3 0.4 1-month-old chicks, where it constitutes about 3% total content muscle. In cultured cells calcium-sensitive phosphoprotein increased 0.015 at 2 days 0.04 0.05 after 5 culture. This amount represents 0.5% accumulation Ca2+ transport began during fusion continued a linear rate 8 density 75 A intramembranous particles seen freeze-etch electron microscopy on fracture faces is 4,000/mum2 adult chick but only 400/mum2 rough proportion Ca2+-sensitive phosphoprotein. Ca2+, Na+, K+ medium addition ouabain, caffeine, or calcium ionophores A23187 X537A sharply influence cells, parallel their effect upon cell growth. These observations are consistent proposition that gene expression leading may be regulated intracellular ion concentrations.