Effect of transdermal estradiol therapy on bone mineral density of amenorrheic female athletes.

BACKGROUND: The effects of transdermal estradiol treatment (HT) in amenorrheic athletes (AA) with low body weight (BW) and low bone mineral density (BMD) are unknown. PURPOSE: To investigate whether HT increases BMD in AA with low BW and to compare the results with levels in AA who have recovered spontaneous menstruation (SM). METHODS: Female athletes (n = 151) were recruited at the Japan Institute of Sports Sciences and the University of Tokyo. All participants were divided into four groups: an AA group (untreated group) (n = 36), a HT group (n = 55), a SM group (n = 21), and an eumenorrheic athletes (EA) group (n = 39). Height, body weight, blood tests, and dual-energy X-ray absorptiometry were measured at baseline and after 12 months. The HT group was treated daily for 12 months with transdermal estrogen therapy. In addition, participants received oral progestin for 7 days once every 3 months. RESULTS: After 12 months, BMD in the AA group was significantly lower than at baseline; however, BMD in the other three groups was significantly higher than at baseline. The ratio of the change in BMD values before and after 12 months was -1.6 ± 3.2% for the AA group, 5.3 ± 8.7% for the HT group, 11.1 ± 8.9% for the SM group, and 2.3 ± 5.7% for the EA group. The rate of change in BMD values in the SM group was greater than that in the HT group. CONCLUSION: HT increased BMD in AA with low BW, and the increase in those with SM was greater than that in those treated with HT.

Effect of estradiol on histopathology of brain in unilateral and bilateral ovariectomized rats.

Estradiol, a major form of estrogen, plays a crucial role in various aspects of brain function, including neuronal health, synaptic plasticity, and cognitive processes. Therefore, it is of interest to investigate the histopathological changes of the rat brain following estradiol treatment in unilateral and bilateral ovariectomized rats, a commonly used method to induce estrogen deficiency and study the consequences of hormonal changes. Two months old Wistar albino female rats were divided into five experimental groups, each consisting of 6 animals. Unilateral and bilateral ovariectomized rats were treated with estradiol (10 mg/Kg/b.wt) subcutaneously for 30 days. The histopathological analysis of brain revealed normal 5-6 compact layers of small pyramidal cells of CA3 region, most with vesicular nuclei in control rats andan irregular and disturbed thickness of the pyramidal cell layer in the CA3 region, suggesting neuronal loss in unilateral ovariectomized rats. Estradiol therapy to these rats showed dark hyperchromatic layers of pyramidal cells in the CA3 region, most of which displayed vesicular nuclei and less shrinkage. Bilateral ovariectomized rats without estradiol treatment showed irregular and disturbed thickness of the pyramidal cell layer in the CA3 region Similar to Group II, indicating neuronal loss and bilateral ovariectomized rats with estradiol treatment showed no significant changes. These findings highlight the potential role of estradiol in modulating the histopathological changes associated with ovariectomy. Further research is warranted to elucidate the underlying mechanisms through which estradiol exerts its effects on neuronal integrity and to explore potential therapeutic strategies for preventing or reversing these histological changes.