tailieunhanh - báo cáo hóa học:" Mechanically-induced osteogenesis in the cortical bone of pre- to peripubertal stage and peri- to postpubertal stage mice"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học quốc tế đề tài : Mechanically-induced osteogenesis in the cortical bone of pre- to peripubertal stage and peri- to postpubertal stage mice | Journal of Orthopaedic Surgery and Research BioMed Central Open Access Research article Mechanically-induced osteogenesis in the cortical bone of pre- to peripubertal stage and peri- to postpubertal stage mice Jeffrey H Plochocki1 2 Address Department of Anatomy Midwestern University Glendale Arizona USA and 2Department of Biology The Pennsylvania State University Altoona Pennsylvania USA Email Jeffrey H Plochocki - jploch@ Published 25 June 2009 Received 26 November 2008 Journal of Orthopaedic Surgery and Research 2009 4 22 doi 1749-799X-4-22 Accepted 25 June 2009 This article is available from http content 4 1 22 2009 Plochocki licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Exercise during postnatal development plays a key role in determining adult bone mass and reducing the risk of fracture and osteoporosis later in life. However the relationship between mechanically-induced osteogenesis and age is unclear. Elevated levels of estrogen during puberty may inhibit periosteal bone formation. Thus magnitudes of mechanically-induced osteogenesis may be vary with pubertal state. Methods The present study uses a murine model to examine age-related changes in bone formation at the femoral midshaft with voluntary exercise. Pre- to peripubertal mice aged 3 weeks and peri- to postpubertal mice aged 7 weeks were randomly divided into sedentary and exercised groups and subjected to histomorphometric comparison after 4 weeks of treatment. Results Results of the experiment indicate that exercise significantly increased osteogenesis on the periosteal and endocortical surface of the mice in the older age group P . Exercise had no significant effect on bone formation of .