Trace elements in phasic and tonic muscles.

The differences in the content of trace elements (Fe, Cu, Zn, Br, Rb and Sr) in phasic and tonic scallop adductor muscles have been revealed by using X-ray fluorescence analysis. The phasic (yellow) muscles have been found to be richer in Fe and Cu while more deficient in Zn and Br as compared to the tonic (white) muscles. No appreciable differences in the Rb and Sr content has been found. A statistical treatment of the data obtained suggests that phasic and tonic muscles differ in their metabolism of trace elements and the regulation of the concentrations of various trace elements by the muscle cell is achieved by different mechanisms.