BONE AND MINERAL METABOLISM IN BLACKS AND WHITES

本次竞争更新中提出的调查目的 应用的目的是确定增加骨量和 黑人和黑人的骨形成和更新率下降 导致或导致骨质疏松症的低发病率 和骨折，以研究更年期和 衰老对黑人骨骼和矿物质代谢的影响并研究 黑人老年或 II 型骨质疏松症的发病机制。 假设 需要研究的是 a) 黑人的骨吸收率较低 比白人多，是由于破骨细胞功能改变引起的 外周单核细胞产生的骨吸收细胞因子减少 和骨细胞，并伴有骨骼反应减弱 甲状旁腺激素，b) 黑人的骨量越大，不会导致 仅来自骨骼重塑的减少，而是来自成骨细胞的改变 功能：生长因子产生量的差异 成骨细胞或储存在骨中，它们的结合蛋白或一些 组合，c）绝经期雌激素产生的损失 黑人女性导致骨吸收增强，这是由 外周单核细胞和成骨细胞产生的细胞因子增加 并与骨吸收和骨质流失增加有关 Premarin 可以逆转这些变化，d) 老年黑人无法做到这一点 由于年龄相关的钙水平下降，适应低钙饮食 肾脏产生 1,25-二羟基维生素 D 并增加 骨骼重塑的速度，以及，e) 肾脏产生的损害 1,25-二羟基维生素D在老年发病机制中发挥重要作用 黑人骨质疏松症。 这些研究结果应该提供新的 以及有关骨质疏松症发病机制的有用信息 黑人并可能带来可用于诊断的新方法， 疾病的治疗和预防。

The purpose of the investigations proposed in this competing renewal application is to determine the means by which increases in bone mass and decreases in rates of bone formation and turnover occur in blacks and contribute to or are responsible for the low incidence of osteoporosis and fractures in them, to investigate the effects of the menopause and aging on bone and mineral metabolism in blacks and to investigate the pathogenesis of senile or type II osteoporosis in blacks. The hypotheses to be investigated are a) that bone resorption rate is lower in blacks than in whites and results from altered osteoclast function caused by diminished production of bone-resorbing cytokines by peripheral monocytes and bone cells and is accompanied by diminished skeletal response to parathyroid hormone, b) that the greater bone mass in blacks results not only from a reduction in skeletal remodeling but from altered osteoblast function: differences in the amount of growth factors produced by osteoblasts or stored in bone, their binding proteins or some combination, c) that loss of estrogen production at the menopause in black women results in enhanced bone resorption that is caused by increased production of cytokines by peripheral monocytes and osteoblasts and is associated with increased bone resorption and bone loss and that these changes are reversed by Premarin, d) that aging blacks are unable to adapt to a low calcium diet because of an age-related decline in the renal production of 1,25- dihydroxyvitamin D and have increases in the rate of skeletal remodeling and, e) that impaired renal production of 1,25-dihydroxyvitamin D is important in the pathogenesis of senile osteoporosis in blacks. The results of these studies should provide new and useful information concerning the pathogenesis of osteoporosis in blacks and could lead to new methods that can be used for the diagnosis, treatment and prevention of the disease.