Smith M W, Bruns M E, Lawson E D
Biochem J. 1985 Jan 1;225(1):127-33. doi: 10.1042/bj2250127.
The location of intestinal cells taken from the base of the crypt to the tip of the villus responsive to calcitriol (1,25-dihydroxycholecalciferol) and the distribution of [3H]calcitriol within the intestinal epithelium has been determined in vitamin D-deficient rats. The calcitriol responses examined were CaBP (Ca2+-binding protein) levels as measured by immunodiffusion and alkaline phosphatase levels as determined cytochemically. Calcitriol had no effect on villus structure or on enterocyte kinetics. This made it possible to compare levels of CaBP and alkaline phosphatase activity in enterocytes at different ages in rats at known times after hormone injection. Cells from both the crypt and villus synthesized CaBP in response to calcitriol. Alkaline phosphatase activity was not detectable in crypt cells, although a pool of precursor was produced in these cells in response to calcitriol. Enzyme activity was increased in all villus cells in response to calcitriol, but the quantitative description of this effect was very different from that found for calcitriol effects on CaBP synthesis. Calcitriol injected into vitamin D-deficient rats was detected, within 2h, in all cells of the crypt and villus. Most of the binding was to sites having a high affinity for the injected hormone.
在维生素 D 缺乏的大鼠中，已确定了从隐窝底部到绒毛尖端对骨化三醇（1,25 - 二羟基胆钙化醇）有反应的肠细胞的位置，以及[3H]骨化三醇在肠上皮内的分布。所检测的骨化三醇反应包括通过免疫扩散测量的 CaBP（钙结合蛋白）水平和通过细胞化学测定的碱性磷酸酶水平。骨化三醇对绒毛结构或肠上皮细胞动力学没有影响。这使得在激素注射后的已知时间，能够比较不同年龄大鼠肠上皮细胞中 CaBP 和碱性磷酸酶活性的水平。隐窝和绒毛的细胞都能响应骨化三醇合成 CaBP。尽管这些细胞响应骨化三醇会产生前体池，但在隐窝细胞中检测不到碱性磷酸酶活性。响应骨化三醇，所有绒毛细胞中的酶活性都增加了，但这种效应的定量描述与骨化三醇对 CaBP 合成的影响非常不同。给维生素 D 缺乏的大鼠注射骨化三醇后，在 2 小时内，在隐窝和绒毛的所有细胞中都检测到了它。大部分结合发生在对注射激素具有高亲和力的位点上。
