Retardation of progressive forelimb regeneration by treatment with neuropharmacological agents.

Intraperitoneal administration of hormones or of certain neuropharmacological agentsdoes not affect initial blastema formation in adult newts (Notophthalmus viridescens). Hormonal treatment accelerates the onset of the morphogenetic phase of regeneration. In contrast, treatment with chlorpromazine (alone or with growth hormone), guanethidine, or atropine retards or represses the onset of morphogenesis. These results suggest that some interaction between the nervous and endocrine systems is required in promoting the proliferative and the morphogenetic stages of forelimb regeneration.