Cyclic AMP and neuroendocrine influence upon forelimb regeneration in the adult newt, Notophthalmus viridescens.

The influence of the nervous and endocrine systems upon successive stages of limb regeneration suggest possible neuroendocrine interaction(s). Intraperitoneal injections of various agents had no effects upon blastema formation. Chlorpromazine, administered alone or with hormones, retarded morphogenesis. Prolactin, dibutyryl cAMP (db-cAMP), theophylline, and acetylcholine accelerated morphogenesis. 5'-AMP had no effect. Only db-cAMP countered the chlorpromazine-induced retardation of morphogenesis. These results suggest that neuroendocrine influences, possibly cAMP-mediated, direct, in part, the morphogenesis of the regeneration blastema.