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Chronic administration of melatonin induces changes in porphyrins and in the histology of male and female hamster Harderian gland: Interrelation with the gonadal status
Author(s) -
RodriguezColunga Maria J.,
Fernandez Covadonga,
Antolin Isaac,
Rodriguez Carmen,
Tolivia Delio,
MenendezPelaez Armando
Publication year - 1991
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.1991.tb00825.x
Subject(s) - melatonin , harderian gland , medicine , endocrinology , hamster , castration , biology , testosterone (patch) , histology , atrophy , hormone , mesocricetus , endocrine system
In this paper, we have investigated the influence of melatonin on the histology and porphyrin content of the Syrian hamster Harderian glands. Daily afternoon injections of 25 μg of melatonin to female hamsters for 12 weeks resulted in the discontinuity of estrous cyclicity, a marked decrease in the Harderian gland intraluminal area occupied by porphyrins, and in a significant rise in the number of Type II cells. A similar decrease in porphyrins was observed after 8 weeks of ovariectomy. However, if the melatonin injections were given for only 8 weeks (without inducing gonadal atrophy), no changes were observed in the area occupied by intraluminal porphyrins, suggesting that the effects of melatonin in female Syrian hamsters might be associated with the subsequent gonadal atrophy. Castration of male hamsters induced a significant increase in porphyrins and a clear drop in the number of Type II cells. These changes were totally prevented when melatonin was administered daily from the day of castration. Our results suggest that melatonin, at least in male Syrian hamsters, plays a role in Harderian metabolism, acting directly on the Handerian secretory cells or indirectly through pituitary hormones.