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The Effect of Orally Administered Melatonin on the Seasonality of Deer Pelage Exchange, Antler Development, LH, FSH, Prolactin, Testosterone, T 3 , T 4 , Cortisol, and Alkaline Phosphatase
Author(s) -
Bubenik G. A.,
Smith P. S.,
Schams D.
Publication year - 1986
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.1986.tb00756.x
Subject(s) - melatonin , prolactin , endocrinology , medicine , antler , testosterone (patch) , alkaline phosphatase , biology , photoperiodism , zoology , hormone , ecology , enzyme , biochemistry
Five milligrams of melatonin (M) per day was administered orally to four male white‐tailed deer on a schedule that mimicked first decreasing and then increasing lengths of natural photoperiod. The following seasonal phenotypic and hormonal responses were observed: 1) Pelage exchange, antler mineralization, velvet shedding, and rutting behavior of experimental animals were advanced by 50–55 days. 2) Prolactin (PRL) levels exhibited a bimodal curve with peaks in May and August, as compared to a monomodal curve of controls (peak in June). 3) Peak FSH levels of M‐fed deer were advanced 2 months as compared to controls (June vs August). 4) LH concentrations of both groups reached maxima in July; however, in the experimental group, LH levels declined much faster than in controls and then rose again in October‐November. 5) Testosterone (T) concentrations of M‐fed bucks were elevated 2 months ahead of controls. 6) Melatonin treatment had no significant effect on seasonal variation of T 3 , or T 4 . 7) No seasonal rhythm of cortisol was seen in either group and no detectable effect of M was evident. 8) No statistical differences in levels of alkaline phosphatase were seen between groups, although concentrations in experimental bucks sharply dropped to basal levels two months ahead of controls.