mechanism of action of estrogen in estropryvic osteoporosis can be reconstructed as
decrease of numbers of OC by decreased OC formation and increased OC natural death
or apoptosis, induction of deceased OC activity by suppression of T cell-mediated
production of inflammatory cytokines by decreased RANK ligand (RANKL) expression
and thereby down-regulation of cytokines, such as, IL-1, IL-6, TNF-, granulocyte-
macrophage colony stimulating factor, macrophage colony stimulating factor, and
prostaglandin E2, and simultaneous stimulation of estrogen (E) receptors on osteoblasts
leading to increased calcium incorporation and increased bone production6. Since
osteoclasts exhibit substantial nitric oxide (NO) synthetase activity, and it has been
observed that increased bone turnover is related to estrogen-dependent increase in
endothelial NO formation in the osteoclasts, it was investigated to be found that estrogen
in these women reduces receptor-mediated superoxide anion production that would
have enhanced biologic activity of endothelial NO (eNO)7.
The apparently easy treatment of osteoporosis is plagued by a serious problem.
Estrogen replacement therapy directed to menopausal women proved effective to increase
bone mass, so it was accepted to be a standard replacement therapy in menopausal
women, but it was implicated in increased incidence of breast and endometrial cancer in
this population. It was not irrational since estrogen has long been known to be a promoter
of breast growth. Discovery of receptors of estrogen in breast malignancy specimens and
responsiveness of estrogen-receptor positive cancers of the breast to tamoxifen, both led
to objections against hormone replacement therapy (HRT) and solved...
Estradiol and Selective Estrogen Receptor Modulators Differentially Regulate Target Genes with Estrogen Receptors and ; Molecular Biology of the Cell, Vol. 15, pp. 1262-1272.
Simoncini, T. and Genazzani, A.R., (2000). Raloxifene Acutely Stimulates Nitric Oxide Release From Human Endothelial Cells Via An Activation Of Endothelial Nitric Oxide Synthase. Journal of Clinical Endocrinology and Metabolism, 85:pp. 2966-2969.
Tee, M.K., Rogatsky, I., Tzagarakis-Foster, C., Cvoro, A., An, J., Christy, R.J., Yamamoto, K.R., and Leitman, D.C., (2004)…
Among these three million people, researchers have come across with the fact that amongst men and women who are over 50 years of age; Osteoporosis is caused in every 1 in 2 women and 1 in 3 men. Thus, due to this disease which affects the bones and makes them poor in state and structure, people have fractures at least once as soon as they reach the age of 50.
According to Sirduso and MacRae (2005: 4), “the term aging refers to a process or group of processes occurring in living organisms that with the passage of time lead to a loss of adaptability, functional impairment, and eventual death” . The effects of aging on the human body can create a great number of consequences for the individual who experiences the changes and deteriorations of their body.
In most cases, osteoporosis begins to develop early in life but is often diagnosed in old people especially women. Bone formation and firming up occurs before one reaches the age of 25 and requires large intake of calcium. After this age, people with reduced bone mass have the risk of developing Osteoporosis.
Under normal conditions, the bone is comprised of protein collagen and calcium ("MedicineNet"). For a healthy adult, bone is continually absorbed by and rebuilt into the body. Bones become larger and heavier as new bone tissue is added faster that existing bone is absorbed.
Bone remodeling is a process that occurs throughout life. There are two types of cells in bone, osteoblasts and osteoclasts. In health, there is a balance between bone resorbing osteoclasts and bone depositing osteoblasts.
S., Sorensen, B., Yasui, Y., Irwin, M. L., Stanczyk, F. Z., Potter, J. D., & Mctiernan, A. (2006). Effect of Exercise on Bone Mineral Density and Lean Mass in Postmenopausal Women. Medicine and Science in Sports and Exercise, 38 (7), 1236-1244. (Primary Source – From
These findings however, have been found to be greatly influenced by the set of genes acquired by the person. Most of these loci have been actually associated with the low BMD, with these genes increasing the risk factor exponentially in
Experts have specified that number of older people suffering from osteoporosis will continue to increase with increment in world population. Eighty percent of abovementioned sufferers are women, and particularly women older than fifty years of age. Besides different risk factors, ethnicity plays a significant role in the development of osteoporosis.