Creatine phosphokinase in cultured control and dystrophic chick embryo muscle

Abstract

Myogenesis and development of control and dystrophic chick embryo muscle cells in tissue culture were followed for periods up to 57 days. Control myofibers generally showed earlier and more vigorous contractile activity than dystrophics, and in controls detachment of the center of the cell mat occurred at about 3–4 weeks. CPK activity of control cultures increased to maximum values by 3–4 weeks and then declined. In dystrophic cultures, CPK activities increased to levels somewhat greater than controls before declining, and maximum levels occurred over a wider time range. In the medium from dystrophic cultures, CPK activity increased markedly, when cell CPK activity was rapidly declining. Maximum medium CPK activities in dystrophics were, on the average, two and one-half times greater than any control medium value. In controls there was no consistent correlation between maximum medium CPK activity and any phase of cell CPK activity. There were no marked differences, in DNA and protein content, between control and dystrophic cultures, and these parameters primarily reflected the fibroblast component of the culture. None of the differences between control and dystrophic cultures was markedly affected by the proportion of myoblasts to fibroblasts in the original tissue culture inoculum. These results are discussed in reference to the validity of determining CPK activity as a quantitative approach to investigating dystrophic muscle in tissue culture.