Forelimb regeneration in hypophysectomized adult Diemictylus viridescens following organ culture and autoplastic implantation of the adenohypophysis

Abstract

ABSTRACT After autografting an organ-cultured anterior pituitary gland, maintained in culture for up to 27 days, into the tail or lower jaw of an hypophysectomized adult Diemictylus viridescens, the animals recovered and survived readily until fixation at 102 days (129 days post-hypophysectomy) and normal bilateral limb regeneration occurred. Also, restoration of normal skin colour, muscle tone, eating habits and behaviour was identical to control regenerate cases. In the sham control cases, a muscle fragment from the dismembered portion of the amputated left forelimb was placed in organ culture one day after hypophysectomy and then autografted into the host tail 7 days later. The majority of animals lived only up to 28 days post-hypophysectomy; they acquired the gross characteristics of adult hypophy-sectomized newts; and bilateral forelimb regeneration was thwarted. Newts that were hypophysectomized only, showed no gross signs of limb regeneration and died within 28 days. Organ culture and autoplastic implantation of the adenohypophysis permitted a study of the inhibition and then the concurrent restoration (left forelimb = old amputee) and initiation (right forelimb) of regenerative activity as well as normal advanced limb regeneration.