The effect of temperature on the kinetic properties of lactate dehydrogenase from embryos of various fish species

Temperature dependence of apparent Km for pyruvate of LDH from the embryos of seven species of fishes was analyzed. For the embryos of rainbow trout, autumn cisco and least (Siberian) cisco, the Km minima were observed at 5–8°C; for zebrafish, carp and goldfish they were at 25–28°C, and for the loach, at 13–16°C. During embryonic and larval development of rainbow trout proceeding at gradually increasing temperatures, the Km minimum was found to vary in parallel with the optimal temperature. For the embryos of rainbow trout whose development proceeds at constant temperature, the position of the Km minimum at the early gastrula stage and at hatching was the same.