Influence of melatonin on rat thyroid, adrenals and testis secretion during the day
Zwirska-Korczała, K.; Kniazewski, B.; Ostrowska, Z.; Buntner, B.
Folia Histochemica et Cytobiologica 29(1): 19-24
1991
ISSN/ISBN: 0239-8508 PMID: 1783094 Document Number: 368150
The effect of pinealectomy and exogenous melatonin on circadian rhythm of triiodothyronine (T3), thyroxin (T4), corticosterone and testosterone in sham-operated and pinealectomized rats were investigated. The hormone concentrations were RIA-measured and the circadian rhythm secretion were analyzed by cosinor method. The findings suggest that pinealectomy abolishes the rhythmical character of corticosterone secretion and disturbs the circadian rhythm of T3, T4 and testosterone. Exogenous melatonin has the suppressive effect of diurnal secretion of T3, T4 and testosterone in pinealectomized rats but stimulates the rhythmical corticosterone secretion.