Chakraborty C, Dey S K, Davis D L
Dept. of Obstet. Gynecol. and Physiol., University of Kansas, Kansas City 66103.
J Anim Sci. 1989 Apr;67(4):991-8. doi: 10.2527/jas1989.674991x.
The profile of catechol estrogen formation by pig conceptuses from d 14 to 20 of pregnancy (d 0 = 1st d of estrus) was studied using a direct product isolation assay for estrogen-2/4-hydroxylase (E-2/4-H). High performance liquid chromatography was coupled to detection of radioactive products in a flowing system to separate the 2- and 4-hydroxyestradiol (2- and 4-OH-E2) formed from estradiol. The major product was 2-OH-E2; its formation increased with increasing amounts of nicotinamide cofactors and exhibited a preference for NADPH. Maximum velocities were 909 and 154 pmol.mg protein-1.30 min-1, and apparent Michaelis constants were 7.14 and 5.12 microns, for 2- and 4-OH-E2 formation, respectively. Homogenates of d-13 conceptuses produced 1,151 +/- 142 pmol.mg protein-1.30 min-1 of 2-OH-E2. Estradiol-2-hydroxylase was affected (P less than .01) by day of pregnancy, and day effects from d 14 to 20 were described by a fourth-order equation (P less than .001). Conceptuses collected on d 14 produced 119 +/- 15.4 pmol of 2-OH-E2.mg protein-1.30 min-1. By d 15, E-2-activity had declined to 15.7 +/- 1.8 pmol.mg protein-1.30 min-1. Formation of 2-OH-E2 increased to 64.2 +/- 15.4 pmol.mg protein-1.30 min-1 on d 17, remained stable through d 19, and was 39.4 +/- 13.8 pmol.mg protein-1. 30 min-1 on d 20. Therefore, E-2/4-H activity appears to be regulated from d 14 to 20 of pregnancy in pigs; it may participate in the establishment of pregnancy.
利用雌激素 - 2/4 - 羟化酶（E - 2/4 - H）的直接产物分离测定法，研究了妊娠第14至20天（第0天 = 发情第一天）猪胚胎中儿茶酚雌激素的形成情况。高效液相色谱与流动系统中放射性产物的检测相结合，以分离由雌二醇形成的2 - 和4 - 羟基雌二醇（2 - 和4 - OH - E2）。主要产物是2 - OH - E2；其形成随着烟酰胺辅因子量的增加而增加，并且对NADPH表现出偏好。对于2 - 和4 - OH - E2的形成，最大速度分别为909和154 pmol·mg蛋白⁻¹·30 min⁻¹，表观米氏常数分别为7.14和5.12 μmol。妊娠第13天胚胎的匀浆产生1151±142 pmol·mg蛋白⁻¹·30 min⁻¹的2 - OH - E2。雌二醇 - 2 - 羟化酶受妊娠天数的影响（P <.01），第14至20天的天数效应可用四阶方程描述（P <.001）。在第14天收集的胚胎产生119±15.4 pmol的2 - OH - E2·mg蛋白⁻¹·30 min⁻¹。到第15天，E - 2活性已降至15.7±1.8 pmol·mg蛋白⁻¹·30 min⁻¹。2 - OH - E2的形成在第17天增加到64.2±15.4 pmol·mg蛋白⁻¹·30 min⁻¹，并在第19天之前保持稳定，在第20天为39.4±13.8 pmol·mg蛋白⁻¹·30 min⁻¹。因此，在猪妊娠第14至20天期间，E - 2/4 - H活性似乎受到调节；它可能参与妊娠的建立。
