EFFECT OF TREATMENT WITH MELATONIN ON THE PITUITARY--TESTICULAR AXIS OF THE MALE RAT

L. DEBELJUK, V. M. FEDER, O. A. PAULUCCI
1970 Reproduction  
In recent years, there has been increasing evidence to suggest that the pineal gland has some influence on the reproductive functions (Relkin, 1966). This influence seems to be inhibitory and is probably mediated through an indolic substance, melatonin, synthesized by this gland (Wurtman & Axelrod, 1965) . Debeljuk (1969) demonstrated that the treatment with melatonin decreases testicular, adenohypophysial and seminal vesicular weight, without apparently affecting the pituitary levels of fsh
more » ... lh. The experiment described here was performed in an attempt to investigate this apparent lack of effect on pituitary gonadotrophins, prolonging the period of administration of melatonin. Male rats of the Wistar strain were used under normal lighting conditions. When 21 days old, the rats were each injected with 300 \ g=m\ g of melatonin/day. Melatonin was dissolved in 10% ethanol and injected in a volume of 0\m=.\5ml. Control rats were injected with the vehicle only. After 30 days of treatment, the rats were killed and the weight of their bodies, adenohypophyses, testes and seminal vesicles recorded. The adenohypophyses were then quickly homogenized in saline, frozen, and stored at \m=-\20\s=deg\C until assayed for gonadotrophins.
doi:10.1530/jrf.0.0210363 pmid:5443220 fatcat:zmwb63szsjfbpku6c5ciwdwcwi