Toxic effects of maternal methadone administration on cardiac development in the neonatal rat: potential participation of altered polyamine levels in growth impairment.

The pattern of development of polyamine levels in hearts of preweanling rats whose mothers received methadone indicated initial deficits in both spermidine and spermine followed by rebound elevations, a pattern consistent with delayed cellular development. Since polyamines are thought to play important roles in nucleic acid and protein synthesis during cellular maturation, these alterations may participate in the retardation of tissue growth seen in the perinatal opiate syndrome.