CALCIUM CONTENT AND DISTRIBUTION IN HUMAN CATARACT
CALCIUM CONTENT AND DISTRIBUTION IN HUMAN CATARACT
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DOI：
10.1016/0014-4835(82)90087-2
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发表时间：
1982-01-01
影响因子：
3.4
通讯作者：
REDDY, VN
中科院分区：
文献类型：
--
作者：
HIGHTOWER, KR;REDDY, VN
根据白内障合作研究组（CCRG）的指南，对印度和美国的褐发性白内障进行了钙含量和分布的测量。混浊的严重程度和程度与结合到膜和通过差速离心分离的不溶性蛋白质的Ca 2+的增加密切相关。结合的Ca 2+为约未成熟白内障为30 ng/mg，淡黄色为100 ng/ml，成熟白内障为200 ng/mg，棕色褐变为300 ng/mg。这些值可与新鲜切除的兔透镜的16 ng/mg（0.2 mM）进行比较。在某种程度上，成熟的白内障代表一个先进的阶段和未成熟的白内障的早期发展阶段，同样的棕色和浅黄色白内障，本研究的结果表明，白内障的发展是不伴随着，或结果，游离和结合钙的重新分配。在美国和印度白内障的早期和晚期阶段，与膜和不溶性蛋白结合的总钙的分数是相同的。随着Ca在发展中的白内障中的积累，越来越多的量成为膜或蛋白质结合的，而可扩散的Ca 2+的水平继续增加。在晚期，10，000 g上清液中多达85%的Ca是可透析或可扩散的。剩余的15%与水溶性蛋白结合，分别代表成熟白内障和棕色白内障的6- 15倍增加。在含有不溶性蛋白质和膜碎片的1000 g沉淀中发现的Ca量也有相当大的增加。
The Ca content and distribution was measured in brunescent cataracts from India and cataracts from the USA classified according to guidelines of the Cooperative Cataract Research Group (CCRG). The severity and extent of opacification correlates well with the increase in Ca2+ bound to membranes and insoluble proteins separated by differential centrifugation. Bound Ca2+ is .apprx. 30 ng/mg for the immature cataract, 100 ng/ml for the pale yellow, 200 ng/mg for the mature cataract and 300 ng/mg for the brown brunescent. These values can be compared to 16 ng/mg (0.2 mM) for a freshly excised rabbit lens. To the extent that the mature cataract represents an advanced stage and the immature cataract an early stage of development, and likewise for the brown and pale yellow cataract, results of this study suggest that cataract development is not accompanied by, or the result of, a redistribution of free and bound Ca. The fraction of total Ca bound to membranes and insoluble proteins is the same in the early and advanced stages of USA and Indian cataracts. It appears that as Ca accumulates in the developing cataract, an increasing amount becomes membrane or protein bound while the leve of diffusible Ca2+ continues to increase. In the advanced stage as much as 85% of the Ca in the 10,000 g supernatant is dialyzable or diffusible. The remaining 15% is bound to watersoluble proteins and represents a 6- to 15-fold increase in the mature and brown cataract, respectively. There is also a considerable increase in the amount of Ca found in the 1000 g pellet containing insoluble proteins and membrane fragments.