{'fraction_non_alphanumeric': 0.04503582395087001, 'fraction_numerical': 0.04094165813715456, 'mean_word_length': 5.434210526315789, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Expression of 25-hydroxyvitamin D3-1alpha-hydroxylase along the nephron: new insights into renal vitamin D metabolism.

Renal synthesis of the active form of vitamin D, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], is a pivotal step in calcium and phosphate homeostasis. Production of 1,25(OH)2D3 is catalyzed by the mitchondrial cytochrome P450, 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-HYD). As a consequence of the tight regulation of vitamin D metabolism during normal physiology, studies of the expression and regulation of 1alpha-HYD have proved remarkably difficult. However, the recent cloning of the gene for 1alpha-HYD has enabled a more comprehensive analysis of the tissue distribution of 1alpha-HYD, as well as the mechanisms involved in controlling 1,25(OH)2D3 production. In particular, an understanding of site-specific expression and regulation of 1alpha-HYD along the nephron might help to elucidate a more versatile role for 1,25(OH)2D3 in renal physiology.