Massaro E R, Simpson R U, DeLuca H F
Am J Physiol. 1983 Mar;244(3):E230-5. doi: 10.1152/ajpendo.1983.244.3.E230.
The ontogenesis of the 1,25-dihydroxyvitamin D3 specific binding activity in intestine was examined in vitamin D-deficient and replete rats. The absence of binding activity in intestines during the first two postnatal weeks was not influenced by vitamin D supplementation. The concentration of binding sites peaked on day 18 in vitamin D-replete rats and preceded that in the deficient group by approximately 1 wk. The influence of glucocorticoids on 1,25-dihydroxyvitamin D3-binding protein levels was examined by sequential hydrocortisone administration and adrenalectomy. Subcutaneous hydrocortisone administration before day 14 postpartum did not induce binding activity. The concentration of binding sites was significantly increased to 369 +/- 60 fmol/mg of protein by hydrocortisone injections from days 15 to 17 postpartum when compared with an average of 182 +/- 16 fmol/mg of protein in littermate controls. Hydrocortisone administration did not further increase receptor levels in rats injected from days 19 to 21. Bilateral adrenalectomy on day 17 postpartum significantly decreased the concentration of binding sites. It is concluded that adrenal glucocorticoids play an important role in the developmental appearance of 1,25-dihydroxyvitamin D3 specific binding activity in the postnatal rat intestine.
在维生素D缺乏和充足的大鼠中，研究了肠道中1,25 - 二羟基维生素D3特异性结合活性的个体发生。出生后前两周肠道中缺乏结合活性，这不受维生素D补充的影响。在维生素D充足的大鼠中，结合位点浓度在第18天达到峰值，比缺乏组提前约1周。通过连续给予氢化可的松和肾上腺切除术，研究了糖皮质激素对1,25 - 二羟基维生素D3结合蛋白水平的影响。产后第14天前皮下注射氢化可的松未诱导出结合活性。与同窝对照平均182±16 fmol/mg蛋白质相比，产后第15至17天注射氢化可的松后，结合位点浓度显著增加至369±60 fmol/mg蛋白质。在第19至21天注射的大鼠中，给予氢化可的松并未进一步提高受体水平。产后第17天双侧肾上腺切除术显著降低了结合位点的浓度。结论是，肾上腺糖皮质激素在出生后大鼠肠道中1,25 - 二羟基维生素D3特异性结合活性的发育出现中起重要作用。
