Protein synthesis in tissues of fed and starved carp, acclimated to different temperatures

The temperature dependence of the rates of protein synthesis in the red and white skeletal muscle of the carp (Cyprinus carpio) was measured using a method which involved a single injection of tritiated phenylalanine. Plasma and muscle-free phenylalanine quickly reached a plateau level at all temperatures. During the plateau phase the incorporation of label into protein was liner. Muscle from fish previously acclimated to either a low temperature (8°C) or a high temperature (28°C), showed marked differences in the rates of protein synthesis. The results show that cold acclimation is associated with significantly higher rates of protein synthesis (p<0.001) in both red and white muscle. Arrhenius activation energies, derived from the rates of protein synthesis at the different experimental temperatures, were similar for both red and white muscle in fish acclimated to warm or cold temperatures. Measurements for both acclimated groups over the temperature range 8-34°C showed that the activation energy for the process of protein synthesis was 86.7 kJ/mol and 78.7 kJ/mol for the red and white muscle respectively.