Polyamines and diamines in regenerating tissues of the Japanese newt, Triturus (Cynops) pyrrhogaster

Newt forelimb and tail regenerates of various stages were analyzed for their contents of diamines and polyamines, including putrescine, spermidine, spermine, sym‐homospermidine, and cadaverine. All the regenerates were particularly rich in putrescine and spermidine among the amines tested. The putrescine level in forelimb regenerates continued to increase during the bud formation period to reach a maximum at 45 days after amputation (“palette stage” to “medium digit stage”) and then decreased. In tail regenerates, putrescine level doubled within 14 days, reached a peak at 26 days, and then decreased gradually. The spermidine level in forelimb regenerates increased gradually for 45 days after amputation and decreased thereafter, while that in tail regenerates reached a peak at 26 days and remained nearly constant thereafter. The spermine and sym‐homospermidine concentration changed little throughout the experiment. Cadaverine levels were lower in the regenerates of the male newt than in intact tissues.