Effect of pregnancy on the turnover of lactate dehydrogenase and its isoenzymes in mouse tissues.

The turnover characteristics of total protein and of lactate dehydrogenase and its isoenzymes have been determined in several tissues of the mouse during the later stages of pregnancy. Whereas most tissues showed markedly decreased rates of both synthesis and degradation of proteins, the incorporation rate in uterus increased. Significant differences in the extent of isotope distribution between total protein and lactate dehydrogenase and its isozymes were also noted. Overall the concept emerges of a pool of body protein which is responsive to the physiological stresses of pregnancy at the level of both tissue and cellular function.