ABSTRACT
The female reproductive system consists of well-regulated and integrated neuroendocrine signaling pathways between the hypothalamus and the pituitary gland and the ovaries. Feedback control of the reproductive hormones is complex in women. Gonadotropin-releasing hormone is a linear decapeptide with stimulatory action only on luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Both hormones LH and FSH are glycoproteins with alpha and beta sub-units. The most important hormonal alteration seen after menopause is the very low estradiol levels. The ovaries also produce and secrete hormones necessary for the development of secondary sexual characteristics and sustenance of pregnancy until 12 weeks of gestation. Natural estrogens are preferred to synthetic steroids in hormone replacement therapy (HRT). Progestins are synthetic derivatives of progesterone used in HRT. Several epidemiological studies indicate that HRT decreases the incidence of Alzheimer’s disease by 20 to 60%. Observational studies indicate a reduction in cardiovascular disease of 50% in postmenopausal women receiving HRT.
