2,4,5-T effects on cardiac and serum lactic dehydrogenase (LDH) and creatine kinase (CK) isozymes. II. Neonatal enzyme activities and isozyme profiles.

Neonates from CD-1 mice, which were treated during gestation with 100 mg/kg of 2,4,5-T, were studied from day 1 to 30 postpartum (pp) for effects on cardiac development by determining total cardiac activities and isozyme profiles of LDH and CK. On day 1pp, the total activities and isozyme profiles of LDH of the neonatal hearts were normal. During the developmental period of day 7 through 15, changes were noted in the developmental pattern of LDH isozymes some of which continued to day 30. The CK isozyme profile on day 1pp showed a significant change and changes continued throughout the lactational period. During this period, the normal developmental isozyme patterns of LDH and CK were altered by prenatal exposure to 2,4,5-T suggesting metabolic derangement or pathological changes in the neonatal heart.