effects of melatonin administration on some endocrine functions in rats

ABSTRACT

This study was conducted to investigate the effects of chronic oral melatonin administration in dose of 0.4 mg/kg B.W. daily for 30 days on serum TSH, T4, FSH, LH and insulin. 160 albino rats of both sexes were used, they were grouped into 16 groups, of which 8 groups were used to investigate the endocrinal effects of melatonin in both light and dark conditions. The other 8 groups were used for the same investigations under stressful condition in both light and dark as well. Half of all these groups were served as placebo controls. It was concluded that exogenous melatonin is recommended only as replacement therapy for persons sleeping in light to avoid disturbance of thyroid function especially in hyperthyroid patients. Also, melatonin has no role in counteracting the effects of acute stress on the endocrine functions related to TSH, T4, LH, FSH and insulin