The role of estrogen and Cu, Zn-SOD on histological changes after menopause in female rat parotid.

Objective: Generally, postclimacteric women are susceptible to xerostomia. Therefore, correlations between xerostomia and sex hormones have been studied. Previously, we reported that a reduction of estrogen (belongs to female hormones) could have influence on age-related histological changes in female rat parotids induced by apoptosis. One component of inducing apoptosis is free radical. Recently, it have been noticed that free radical have an effect on aging. A living body has superoxide dismutase (SOD), which can eliminate free radical. SOD decreases according as aging. Therefore, we investigated that the role of estrogen and Cu, Zn-SOD on histological changes after menopause in female rat parotid.

Methods: Apoptosis was observed by TUNEL staining. Cu, Zn-SOD was examined by immunochemical staining. Cu, Zn-SOD and apoptosis of rats having undergone only ovariectomy were compared to rats with natural aging and to those having been administered estrogen infusion after ovariectomy.

Results: In natural aging groups, TLI (TUNEL labeling index) mean of postmenopausal rats significantly showed higher than premenopause. On groups of ovariectomized rat, TLI means with estrogen infusion after ovariectomy were significantly lower than only ovariectomy. The positive Cu, Zn-SOD in groups with estrogen infusion after ovariectomy were stronger than a group with only ovariectomy.

Conclusions: Our results suggested that estrogen and Cu, Zn-SOD could suppress histologically aging changes in parotid of female rat induced by apoptosis and that estrogen could have influence on the production of Cu, Zn-SOD.