The Role of the Pineal Gland and of Environmental Lighting in the Regulation of the Endocrine and Reproductive Systems of Rodents

摘要

Studies were performed to determine whether the pineal gland and the photoperiod play an important role in the regulation of certain endocrine and reproductive functions of rats and hamsters. A specially designed instrument is described that simplifies and speeds removal of the pineal glands. The major conclusions are: Exposure of hamsters to short daily photoperiods (1 to 2 hr/day) or removal of the eyes results in atrophy of the reproductive organs. Pinealectomy prevents this atrophy. Removal of one testis from a dark-exposed hamster prevents gonadal atrophy attendant on short daily photoperiods. The degree of compensatory adrenal enlargement following unilateral adrenalectomy in female albino rats kept in long or short daily photoperiods is similar. This response is not altered by removal of the pineal gland. (Author)