Effects of growth hormone and nutrient on limb regeneration in hypophysectomized adult newts.

The effect of hypophysectomy, growth hormone (GH) and an amino acid-glucose mixture on the regenerative ability of the hypophysectomized Triturus pyrrhogaster yielded the following results: 1 The survival time of hypophysectomized newts can be prolonged substantially by the sulfamide application. 2 Although the limb regeneration in the hypophysectomized newt is retarded as compared with that of the pituitary intact control, it finally completes morphogenetic process under such conditions of prolonged survival. 3 The injection of 100 μg of GH restored the speed of regeneration of pituitary-deprived limbs to almost a normal level. 4 Injections of the amino acid-glucose mixture also promoted the limb regeneration in hypophysectomized newts. However, initial delay in regeneration to the time of bud appearance was not restored by the nutrients.