25-hydroxyvitamin D3-1α-hydroxylase expression in normal and pathological parathyroid glands

摘要: Active vitamin D, 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], plays a pivotal role in calcium homeostasis and bone metabolism. Circulating levels of 1,25(OH)(2)D(3) are thought to be dependent mainly on the activity renal cytochrome P450 enzyme 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase), which is potently induced by PTH. However, 1alpha-hydroxylase or expression has also been reported at several extrarenal sites, local synthesis appears fulfill autocrine paracrine functions. This includes tissues such as placenta brain that express LRP-2/megalin, an endocytic receptor for multiple ligands, involved uptake substrate 1alpha -hydroxylase, D(3). We have previously demonstrated LRP-2/megalin parathyroid cells, here we present results from RT-PCR immunohistochemical analyses showing coincident normal pathological tissue. With real-time quantitative analysis, mRNA was higher majority adenomas secondary hyperplastic glands but lower carcinomas, compared with The findings imply addition feedback control circulating levels, cells may influenced -hydroxylase possible growth regulatory differentiating effects.