INFLUENCE OF AGE ON 7-DEHYDROCHOLESTEROL IN THE SKIN

我们研究计划的目标是确定衰老如何影响 人体皮肤提供足够维生素D营养的能力， 确定老化是否影响皮肤对皮肤刺激的反应性。 维生素D的活性形式，1，25-二羟维生素D。 我们开发了 技术和专门知识，以（a）合成放射性标记的 7-脱氢胆固醇，（B）色谱分离7-脱氢胆固醇 从其光产物和胆固醇，（c）培养人角质形成细胞， 及（d）进行人体研究，以定量确定 紫外线照射对维生素D内分泌系统的影响。 在接下来的5年里，我们计划有条不紊地 (a)确定导致年龄依赖性降低的机制 在表皮7-脱氢胆固醇储存中，（B）评价老化是否 影响人角质形成细胞对 1，25-（OH）2-D3，（c）检查老化对 人类志愿者提高循环中维生素D的浓度， （d）对暴露于紫外线辐射的反应， 身体的表面区域需要暴露于太阳辐射， 提供足够的维生素D营养，（e）确定是否一个单一的长期 暴露于或多次短时间暴露于紫外线辐射具有相同的效果， 维生素D内分泌系统，和（f）确定什么影响的变化， 纬度对皮肤产生维生素D3的能力有影响。 结果 这项研究应该提供关于衰老是如何 影响人体皮肤产生维生素D3的能力， 关于老年人如何利用自然资源的宝贵新信息 为他们提供充足的维生素D营养， 来源不足。

The goals of our research program are to define how aging affects the capacity of human skin to provide adequate vitamin D nutrition and to determine whether aging affects the responsiveness of the skin to the active form of vitamin D, 1,25-dihydroxyvitamin D. We have developed the technology and the expertise to (a) synthesis radiolabeled 7-dehydrocholesterol, (b) chromatographically separate 7-dehydrocholesterol from its photoproducts and cholesterol, (c) culture human keratinocytes, and (d) conduct human studies to quantitatively determine the effect of exposure to ultraviolet radiation on the vitamin D endocrine system. During the next 5 years of this grant we plan, in a methodical fashion, to (a) determine the mechanism(s) responsible for the age-dependent decrease in epidermal 7-dehydrocholesterol stores, (b) evaluate whether aging affects the responsiveness of human keratinocytes to respond to 1,25-(OH)2-D3, (c) examine the effect that aging has on the ability of human volunteers to raise circulating concentrations of vitamin D in response to exposure to ultraviolet radiation, (d) determine how much surface area of the body needs to be exposed to solar radiation in order to provide adequate vitamin D nutrition, (e) determine whether a single long exposure or multiple short exposures to UV radiation has the same effect on the vitamin D endocrine system, and (f) determine what effect changes in latitude has on the capacity of the skin to produce vitamin D3. Results from this research should provide basic new insights about how aging affects the capacity of human skin to produce vitamin D3 and to provide valuable new information about how the elderly can use the natural resource of the sun to provide them with adequate vitamin D nutrition when dietary sources are inadequate.