BONE AND MINERAL METABOLISM IN BLACKS AND WHITES

在这次竞争性延期中提出的调查目的 应用是为了确定骨量增加的方式， 在黑人中，骨形成率和骨转换率降低， 有助于或负责骨质疏松症的低发病率 和骨折，以调查更年期的影响， 衰老对黑人骨和矿物质代谢的影响， 老年或II型骨质疏松症的发病机制在黑人。 的假设 要研究的是a）黑人的骨吸收率较低 这是由于破骨细胞功能的改变， 外周血单核细胞减少骨吸收细胞因子的产生 和骨细胞，并伴有骨骼对 甲状旁腺激素，B）黑人的骨量更大， 不仅是骨骼重塑的减少， 功能：产生的生长因子的量的差异 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， 黑人妇女导致骨吸收增强， 外周单核细胞和成骨细胞产生的细胞因子增加 并与骨吸收和骨丢失增加有关， 这些变化被倍美力逆转，d）衰老的黑人不能 适应低钙饮食，因为年龄相关的下降， 肾脏产生1，25-二羟维生素D，并增加 骨骼重塑的速度，以及，e）受损的肾脏产生的 1，25-二羟维生素D在老年性糖尿病的发病机制中起重要作用 黑人骨质疏松症 这些研究的结果将提供新的 骨质疏松症的发病机制和有用的信息 并可能导致新的方法，可用于诊断， 治疗和预防疾病。

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.