Inhibition of nucleic acid synthesis in the regenerating limb of salamanders treated with a dl-methadone or narcotic antagonists

Enkephalins and Endorphins

“…Exogenous opioids are known to be teratogenic in animals ) and a review of the clinical and laboratory literature reveals that these agonists are antimitotic (Andersen, 1966;Simon, 1963), cytotoxic (Ma, 1931;Sinatra et al, 1978) and damaging to chromosomes (Falek and Hollingsworth, 1980;Fischman et al, 1977). Moreover, in vivo and in vitro studies have demonstrated that opioids can retard growth and development in many diverse organisms and cell types, with a suppression of cell division and alterations in polyamine, nucleic acid, and protein synthetic systems thought to be involved (Hui et al, 1976;Slotkin et al, 1980;Zagon andMcLaughlin, 1977, 1978).…”