Browsing by Subject "Estrogens"

Now showing 1 - 4 of 4
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    Clinical and metabolic effects of the menopause and the role of replacement oestrogen therapy.
    (1970) Utian, Wulf Hessel
    The present investigation was undertaken in order to clarify the clinical and metabolic effects of the menopause following bilateral oophorectomy in the human female and to evaluate the role of subsequent replacement exogenous oestrogen therapy. To this end pertinent clinical and laboratory studies were carried out. It is considered that the following contributions to knowledge have been made: 1. The symptoms and clinical signs directly related to endogenous oestrogen withdrawal following bilateral oophorectomy have been clarified and defined. 2. Symptoms responding to exogenous oestrogen therapy have been differentiated from those responding to placebo (general supportive) therapy. 3. The ability of exogenous oestrogens to produce a feeling of well-being in postmenopausal females is statistically substantiated. 4. The parabasal cell is shown to be the best cytologic index of the oestrogenic status of the postmenopausal female. Claims for an increase of vaginal superficial cells with exogenous oestrogen therapy are refuted. 5. Bi lateral oophorectomy. in the female of reproductive age is shown to have no effect for up to 2 years on the total serum cholesterol level. Oestrogen therapy, however, reduced the level of serum cholesterol in oophorectomized females. 6. The effects of b i lateral oophorectomy on plasma calcium and inorganic phosphorus are shown. The ability of oestrogen to lower plasma calcium and phosphorus is demonstrated and the possible explanation and implication of these findings is discussed. 7. A controlled comparative evaluation of two different forms of oestrogen demonstrates different oestrogens to have different effects. Moreover, endogenous, and exogenous oestrogens are shown to be not entirely similar in their clinical and metabolic effects. 8. The specific short-term sequelae of oophorectomy are demonstrated and the current role of exogenous oestrogen replacement therapy in postmenopausal females is discussed.
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    Kisspeptin signaling is required for the luteinizing hormone response in anestrous ewes following the introduction of males
    (Public Library of Science, 2013) De Bond, Julie-Ann P; Li, Qun; Millar, Robert P; Clarke, Iain J; Smith, Jeremy T
    The introduction of a novel male stimulates the hypothalamic-pituitary-gonadal axis of female sheep during seasonal anestrus, leading to the resumption of follicle maturation and ovulation. How this pheromone cue activates pulsatile secretion of gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) is unknown. We hypothesised that pheromones activate kisspeptin neurons, the product of which is critical for the stimulation of GnRH neurons and fertility. During the non-breeding season, female sheep were exposed to novel males and blood samples collected for analysis of plasma LH profiles. Females without exposure to males served as controls. In addition, one hour before male exposure, a kisspeptin antagonist (P-271) or vehicle was infused into the lateral ventricle and continued for the entire period of male exposure. Introduction of a male led to elevated mean LH levels, due to increased LH pulse amplitude and pulse frequency in females, when compared to females not exposed to a male. Infusion of P-271 abolished this effect of male exposure. Brains were collected after the male effect stimulus and we observed an increase in the percentage of kisspeptin neurons co-expressing Fos, by immunohistochemistry. In addition, the per-cell expression of Kiss1 mRNA was increased in the rostral and mid (but not the caudal) arcuate nucleus (ARC) after male exposure in both aCSF and P-271 treated ewes, but the per-cell content of neurokinin B mRNA was decreased. There was also a generalized increase in Fos positive cells in the rostral and mid ARC as well as the ventromedial hypothalamus of females exposed to males. We conclude that introduction of male sheep to seasonally anestrous female sheep activates kisspeptin neurons and other cells in the hypothalamus, leading to increased GnRH/LH secretion.
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    Prevention of diseases after menopause
    (2014) Lobo, R A; Davis, S R; de Villiers, T J; Gompel, A; Henderson, V W; Hodis, H N; Lumsden, M A; Mack, W J; Shapiro, S; Baber, R J
    AbstractWomen may expect to spend more than a third of their lives after menopause. Beginning in the sixth decade, many chronic diseases will begin to emerge, which will affect both the quality and quantity of a woman's life. Thus, the onset of menopause heralds an opportunity for prevention strategies to improve the quality of life and enhance longevity. Obesity, metabolic syndrome and diabetes, cardiovascular disease, osteoporosis and osteoarthritis, cognitive decline, dementia and depression, and cancer are the major diseases of concern. Prevention strategies at menopause have to begin with screening and careful assessment for risk factors, which should also include molecular and genetic diagnostics, as these become available. Identification of certain risks will then allow directed therapy. Evidence-based prevention for the diseases noted above include lifestyle management, cessation of smoking, curtailing excessive alcohol consumption, a healthy diet and moderate exercise, as well as mentally stimula...
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    Risks and benefits of hormone therapy: has medical dogma now been overturned?
    (2014) Shapiro, S; de Villiers, T J; Pines, A; Sturdee, D W; Baber, R J; Panay, N; Stevenson, J C; Mueck, A O; Burger, H G
    BACKGROUND In an integrated overview of the benefits and risks of menopausal hormone therapy (HT), the Women's Health Initiative (WHI) investigators have claimed that their 'findings … do not support use of this therapy for chronic disease prevention'. In an accompanying editorial, it was claimed that 'the WHI overturned medical dogma regarding menopausal [HT]'. OBJECTIVES To evaluate those claims. METHODS Epidemiological criteria of causation were applied to the evidence. RESULTS A 'global index' purporting to summarize the overall benefit versus the risk of HT was not valid, and it was biased. For coronary heart disease, an increased risk in users of estrogen plus progestogen (E + P), previously reported by the WHI, was not confirmed. The WHI study did not establish that E+ P increases the risk of breast cancer; the findings suggest that unopposed estrogen therapy (ET) does not increase the risk, and may even reduce it. The findings for stroke and pulmonary embolism were compatible with an increased risk, and among E+ P users there were credible reductions in the risk of colorectal and endometrial cancer. For E+ P and ET users, there were credible reductions in the risk of hip fracture. Under 'worst case' and 'best case' assumptions, the changes in the incidence of the outcomes attributable to HT were minor. CONCLUSIONS Over-interpretation and misrepresentation of the WHI findings have damaged the health and well-being of menopausal women by convincing them and their health professionals that the risks of HT outweigh the benefits.