Modulation of 25-hydroxyvitamin D3-24-hydroxylase by aminophylline: a cytochrome P-450 monooxygenase system.
Modulation of 25-hydroxyvitamin D3-24-hydroxylase by aminophylline: a cytochrome P-450 monooxygenase system.
复制标题
氨茶碱对 25-羟基维生素 D3-24-羟化酶的调节：细胞色素 P-450 单加氧酶系统。
DOI：
10.1016/0006-291x(79)91588-2
复制
发表时间：
1979
影响因子：
3.1
通讯作者：
J. G. Ghazarian
中科院分区：
文献类型：
--
作者：
J. A. Kulkowski;T. Chan;J. Martínez;J. G. Ghazarian
鸡肾线粒体25-羟维生素D3-24-羟化酶是细胞色素P-450催化的单加氧酶系统。以78 mg/kg体重的剂量对维生素D3充足的雏鸡给予氨茶碱[3，7-二氢-1，3-二甲基-1H-嘌呤-2，6-二酮与1，2-乙二胺（2：1）的化合物]（一种环核苷酸磷酸二酯酶抑制剂），使24-羟化酶活性增加10倍，而肾脏线粒体细胞色素P-450浓度没有相应增加。反应产物与24，25-二羟维生素D_3在高压液相色谱中共迁移，对高碘酸氧化裂解定量敏感。血清钙浓度从14 mg %下降到9 mg%时，酶活性增加。血清磷浓度保持不变。这些结果支持的想法，肾脏24-羟化酶活性的调节可能是由组织水平的环核苷酸介导的。
The chick kidney mitochondrial 25-hydroxyvitamin D3-24-hydroxylase is a cytochrome P-450 catalyzed monooxygenase system. The administration of aminophylline [3,7-Dihydro-1,3-dimethyl-1H-purine-2,6-dione compounded with 1,2-ethanediamine (2:1)], a cyclic nucleotide phosphodiesterase inhibitor, to vitamin D3-sufficient chicks at a dose of 78 mg/kg body weight increased the 24-hydroxylase activity by 10-fold without a corresponding increase in the kidney mitochondrial cytochrome P-450 concentration. The product of the reaction comigrated with authentic 24,25-dihydroxyvitamin D3in high pressure liquid chromatography and was quantitatively sensitive to periodate oxidation cleavage. The increase in the enzyme activity occurred while serum calcium concentration fell from 14 to 9 mg%. Serum phosphate concentration remained unchanged. These results support the idea that the regulation of kidney 24-hydroxylase activity may be mediated by tissue levels of cyclic nucleotides.