Loss of estrogen upregulates osteoblastogenesis in the murine bone marrow. Evidence for autonomy from factors released during bone resorption.

摘要: Loss of sex steroids causes an increase in both the resorption and formation bone, with former exceeding latter. Based on evidence that increased bone after estrogen loss is due to osteoclastogenesis, we hypothesized also stimulates osteoblastogenesis. We report number mesenchymal osteoblast progenitors murine marrow was two- threefold between 2 8 wk ovariectomy returned control levels by 16 wk. Circulating osteocalcin, as well osteoclastogenesis rate loss, followed a very similar temporal pattern. Inhibition administration bisphosphonate alendronate led decrease absolute progenitors; however, it did not influence stimulating effect osteoblastogenesis or osteoclastogenesis. These observations indicate follows can be explained, at least part, Moreover, they strongly suggest unlike normal remodeling, whereby development stimulated factors released from matrix during osteoclastic resorption, deficiency unleashes signals stimulate differentiation fashion autonomous need created therefore, inappropriate.