EFFECTS OF PINEAL GLAND UPON HAIR CYCLES IN MICE

[摘要] The effect of the pineal gland on the run of the hair growth waves was studied in male C3H/EP mice. Pinealectomy produced acceleration of the hair waves. Hypertrophy of the thyroid and testicles was observed in the pinealectomized mice. The acceleration of the hair waves after pinealectomy was also seen in thyroidectomized and in castrated-thyroidectomized mice. The daily administration of 100 ug of melatonin during 56 days slowed down the progression of the hair waves either in normal or in pineal-ectomized mice. Melatonin inhibited the thyroid hypertrophy found in pinealectomized mice, but did not have any effect upon the size of the thyroid in the sham-operated controls.