Gu A, Sellamuthu R, Himes E, Childress P J, Pelus L M, Orschell C M, Kacena M A
George Washington School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC 20037.
J Musculoskelet Neuronal Interact. 2017 Dec 1;17(4):312-318.
During the reproductive cycle, altered calcium homeostasis is observed due to variable demand for mineral requirements. This results in increased bone resorption during the time period leading up to parturition and subsequent lactation. During lactation, women will lose 1-3% of bone mineral density per month, which is comparable to the loss experienced on an annual basis post-menopausal. The purpose of this study was to determine the effect of parity on bone formation in middle-aged mice.
Mice were mated and grouped by number of parity and compared with age matched nulliparous controls. Measurements were taken of femoral trabecular and cortical bone. Calcium, protein and alkaline phosphatase levels were also measured.
An increase in trabecular bone mineral density was observed when comparing mice that had undergone parity once to the nulliparous control. An overall decrease in trabecular bone mineral density was observed as parity increased from 1 to 5 pregnancies. No alteration was seen in cortical bone formation. No difference was observed when calcium, protein and alkaline phosphatase levels were assessed.
This study demonstrates that number of parity has an impact on trabecular bone formation in middle-aged mice, with substantial changes in bone density seen among the parous groups.
在生殖周期中，由于对矿物质需求的变化，会观察到钙稳态的改变。这导致在分娩和随后的哺乳期之前的时间段内骨吸收增加。在哺乳期，女性每月会损失1%至3%的骨矿物质密度，这与绝经后每年的损失相当。本研究的目的是确定产次对中年小鼠骨形成的影响。
将小鼠交配并按产次分组，与年龄匹配的未生育对照进行比较。对股骨小梁和皮质骨进行测量。还测量了钙、蛋白质和碱性磷酸酶水平。
将经历过一次产次的小鼠与未生育对照进行比较时，观察到小梁骨矿物质密度增加。随着产次从1次增加到5次妊娠，小梁骨矿物质密度总体下降。皮质骨形成未见改变。评估钙、蛋白质和碱性磷酸酶水平时未观察到差异。
本研究表明，产次对中年小鼠的小梁骨形成有影响，在有生育经历的组中观察到骨密度有显著变化。
