POSTPONED HOMOTRANSPLANTS OF THE HYPOPHYSIS INTO THE REGION OF THE MEDIAN EMINENCE IN HYPOPHYSECTOMIZED MALE RATS1

Abstract

In 2 series of Long-Evans male rats pituitary homotransplants were made by the parapharyngeal approach after pituitaryless periods of 60 and 150 days. During these periods no gain, usually a loss, in body weights and testicular atrophy occurred. Autopsies were done 2½ months after the transplantations. In all rats the transplants became functional. In Series I, hypophyscctomized when 38–42 days old, donors were males and females 14–21 days old; in Series II recipients were 47 days old at hypophysectomy and donors were males 21–23 days old. In all animals except 2 of Series I there were pronounced gains in body weights, activation of the thyroids, structural repair of the adrenals and the reproductive organs, and fertility. The weights of the reproductive organs transcended those of normal controls. In 2 rats of Series I there were slower gains in body weights, and activation of the thyroids but no structural repair of the adrenals and reproductive organs. There were no “takes” when Spraguc-Dawley instead of Long-Evans rats were used as donors.