Kaddouri M, Brasset N, Alvinerie M, Eeckhoutte C, Bonfils C, Derancourt J, Galtier P
Laboratoire de Pharmacologie-Toxicologie, INRA, Toulouse, France.
J Steroid Biochem Mol Biol. 1992 Jun;42(5):499-508. doi: 10.1016/0960-0760(92)90262-h.
Age-related changes in progesterone hepatic metabolism were measured in Lacaune ewes in the foetal, neonatal (1 and 4 weeks), growing (7 months), pregnant (11 months) and adult (6 years) stages. 6 beta-Hydroxylation and 20 alpha-reduction were found to be the most efficient metabolic process in ovine microsomes. These activities were detected in 3-month-old foetuses and they increased rapidly during the first month of life, in a similar manner to the developmental expression of the cytochrome P4503A subfamily. 16 alpha- and 21-hydroxylation of progesterone were characterized by low, constant turn over in sheep liver microsomes during development. The hepatic ovine P4502B isozyme was purified to electrophoretic homogeneity by means of successive DEAE cellulose, hydroxylapatite and CM cellulose chromatographic separations. This hemoprotein had an apparent molecular weight of 51 kDa and was characterized by spectral data, NH2-terminal amino-acid sequence, immunological and catalytic properties. The relative contribution of this form and of the previously purified ovine P4503A subfamily was investigated in liver progesterone metabolism by immunoinhibition studies using polyclonal antibodies raised in rabbits and from the existence of induction and of significant correlations between microsomal activity and specific P450 content. In sheep liver microsomes, it would appear that cytochrome P4502B is involved in progesterone 21-hydroxylation whereas P4503A participates in the 6 beta- and 16 alpha-hydroxylation and possibly in the reductive conversion of progesterone in its 20 alpha-hydroxy derivative.
在胎儿期、新生儿期（1周和4周）、生长期（7个月）、孕期（11个月）和成年期（6岁）的拉库纳母羊中，测定了与年龄相关的孕酮肝脏代谢变化。发现6β-羟基化和20α-还原是绵羊微粒体中最有效的代谢过程。这些活性在3个月大的胎儿中即可检测到，并且在出生后的第一个月迅速增加，其方式与细胞色素P4503A亚家族的发育表达相似。孕酮的16α-和21-羟基化在绵羊肝脏微粒体发育过程中的特点是周转率低且恒定。通过连续的DEAE纤维素、羟基磷灰石和CM纤维素色谱分离，将绵羊肝脏P4502B同工酶纯化至电泳纯。这种血红蛋白的表观分子量为51 kDa，并通过光谱数据、氨基末端氨基酸序列、免疫学和催化特性进行了表征。通过使用兔源多克隆抗体的免疫抑制研究以及微粒体活性与特定P450含量之间诱导作用的存在和显著相关性，研究了这种形式与先前纯化的绵羊P4503A亚家族在肝脏孕酮代谢中的相对贡献。在绵羊肝脏微粒体中，细胞色素P4502B似乎参与孕酮的21-羟基化，而P4503A参与6β-和16α-羟基化，并可能参与孕酮向其20α-羟基衍生物的还原转化。
