Without estrogen, more than 30% of all the dopamine neurons disappeared in a major area of the brain that produces the neurotransmitter, dopamine," Redmond says. "This finding is consistent with a lot of observations for which there has been, until now, no explanation. The results of the study shed light on why men, who have less estrogen in their bodies and more androgen to antagonize it, are more likely to develop Parkinson's Disease than pre-menopausal women, and why post-menopausal women are more likely then to develop the disease

Genetic and environmental factors can modulate the level of sensitivity to various hormones, including estrogens. Enhanced sensitivity to estradiol (E2) has been demonstrated in several biological conditions, such as in sheep during the nonbreeding season, in untreated patients with Turner's syndrome, and in the prepubertal state in normal girls. We postulated that secondary responses to hormonal therapy in patients with breast cancer could also result from enhanced E2 sensitivity, developing as an adaptive mechanism to E2 deprivation. The present study used the MCF-7 human breast cancer cell line as a model system to test the concept that enhanced sensitivity to E2 may occur as a result of adaptation to low E2 levels. After depriving MCF-7 cells of estrogens in tissue culture medium for periods of 1-6 months, we established conditions under which replication could be stimulated maximally by 10(-14)-10(-15) mol/L E2. In contrast, wild-type cells not exposed to estrogen deprivation required 10(-10) mol/L E2 to grow at the same rate. Further, the concentration of the antiestrogen, ICI 164384, needed to inhibit growth by 50% in estrogen-deprived cells was much lower than that required in wild-type cells (i.e. 10(-15) vs. 10(-9) mol/L). Nude mice implanted with these estrogen-deprived cells demonstrated an earlier appearance of palpable tumors in response to E2 than animals bearing wild-type cells. Reexposure to 10(-10)-10(-9) mol/L E2, either in vivo or in vitro, returned these cells to the level of estrogen sensitivity observed in wild-type cells. Taken together, these observations suggest that breast cancer cells can adapt to low levels of estrogens by enhancing their sensitivity to E2.

Estrogen deprivation causes estradiol hypersensiti...[J Clin Endocrinol Metab. 1995] - PubMed Result

This may also affect men
"Estrogen's effects on inflammation within the joint are not well known," Dr. Felson and Dr. Cummings observe. Yet, as they note, estrogen has well-established tissue-specific effects on inflammatory cytokines. Estrogen's role in joint inflammation could account for the increased sensitivity to pain that some women suffer with estrogen depletion. Citing studies of pharmacological suppression of estrogen and studies of natural menopause, the authors offer a look at compelling evidence associating estrogen deprivation with joint pain, including:

Joint pain and estrogen deprivation

Estrogen replacement improves verbal memory but not working memory, suggesting that specific actions of hormones affect cognitive function in men with prostate cancer," Beer said.

Researchers also measured negative mood, depression and confusion in the same groups of men using a standard mood test over the course of two separate visits. They found that androgen-deprived men with prostate cancer show significantly increased depression and confusion. Those receiving estrogen therapy reported decreased confusion.

"Though the source of beneficial effects from estrogen remains unclear, the overall outcome of estrogen therapy seems promising for men with prostate cancer," Beer said. "Further studies using additional cognitive measures and control subjects are necessary to develop a better understanding of estrogen's effects on the cognitive functions of prostate cancer patients."

ScienceDaily: Estrogen Boosts Memory In Men With Prostate Cancer

Elevated estrogen disturbs the immune system in a number of ways, including interference with the thymus gland, (4) and has been implicated in the initiation of autoimmune processes. (5) Moreover, too much estrogen in the system may impair the synthesis of cortisol (6) as well as bind active cortisol, thus further exacerbating a cortisol abnormality. It is interesting to note that researchers have discovered that phytoestrogens (estrogen compounds) in tofu and soy-based food decrease cortisol production and increase androgens, some of which convert to estrogen and raise the total estrogen level in the body. (7) When considered together, these factors indicate a vicious cycle of destabilizing cortisol-estrogen interactions

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In normal or euthyroid women receiving estrogen replacement hormone, thyroid function tests remain unchanged. However in hypothyroid women on thyroid replacement hormone, the addition of estrogen therapy caused decreased blood levels of T4. Although the changes were small, they are considered clinically important. Researchers noted that the increased TSH level caused by estrogen therapy resulted in symptoms of hypothyroidism in a number of women in the study. The study’s authors noted that these findings correlate with the improved thyroid function often reported in Graves’ disease patients who begin estrogen therapy, including birth control pills. Estrogen raises the serum thyroxine-binding globulin (protein that carries thyroid hormone in the blood) concentration by slowing its clearance from the blood and by enhancing its production in the body. However, estrogen can stimulate the immune system causing an increased production of thyroid antibodies

How Estrogen Influences Thyroid Function

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