Readhead C, Lobo R A, Kletzky O A
Am J Obstet Gynecol. 1983 Feb 15;145(4):491-5. doi: 10.1016/0002-9378(83)90323-x.
The steroidogenic enzymes 3 beta-hydroxysteroid dehydrogenase and delta 4-5 isomerase (3 beta-HSD) that convert delta 5-hydroxysteroids to delta 4-ketosteroids were measured in human follicular tissue collected during the follicular phase of the menstrual cycle. This study was done in order to determine whether 3 beta-HSD enzyme activity fluctuated during the follicular phase of the menstrual cycle and, if so, whether these changes were reflected by the concentration of steroids in the follicular fluid. A microsomal fraction was prepared from each of 14 follicular-phase follicles, and 3 beta-HSD enzyme activity was estimated by the amount of androstenedione synthesized in the presence of excess substrate (dehydroepiandrosterone) and cofactor (nicotinamide adenine dinucleotide). Androstenedione, dehydroepiandrosterone, and progesterone were measured in the aspirated follicular fluid of each follicle. 3 beta-HSD enzyme activity was undetectable in the smallest (3 to 5 mm) follicles, increased in 5 to 6 mm follicles to 363.2 +/- 60 pmol of androstenedione per milligram per hour, and increased still further in 9 to 11 mm follicles to 5,000 +/- 200 pmol of androstenedione per milligram per hour. The increase in 3 beta-HSD enzyme activity was accompanied by an increase in the concentration of androstenedione in the follicular fluid as well as of progesterone in larger follicles. These data indicate that 3 beta-HSD activity increases during the follicular phase of the menstrual cycle. It is suggested that the primary product of the increased enzyme activity is androstenedione. Since androstenedione is the principal C19 steroid produced by the ovulatory follicle and serves as a substrate for estradiol production, this increase in 3 beta-HSD activity may be important for the associated changes in the late follicular phase that lead to ovulation.
在月经周期卵泡期收集的人卵泡组织中，检测了将δ5 - 羟基类固醇转化为δ4 - 酮类固醇的类固醇生成酶3β - 羟基类固醇脱氢酶和δ4 - 5异构酶（3β - HSD）。进行这项研究是为了确定3β - HSD酶活性在月经周期卵泡期是否波动，如果波动，卵泡液中类固醇浓度是否反映了这些变化。从14个卵泡期卵泡中分别制备微粒体部分，通过在过量底物（脱氢表雄酮）和辅因子（烟酰胺腺嘌呤二核苷酸）存在下合成的雄烯二酮量来估计3β - HSD酶活性。测量每个卵泡抽吸的卵泡液中的雄烯二酮、脱氢表雄酮和孕酮。在最小（3至5毫米）的卵泡中未检测到3β - HSD酶活性，在5至6毫米的卵泡中增加到每毫克每小时363.2±60皮摩尔雄烯二酮，在9至11毫米的卵泡中进一步增加到每毫克每小时5000±200皮摩尔雄烯二酮。3β - HSD酶活性的增加伴随着卵泡液中雄烯二酮浓度以及较大卵泡中孕酮浓度的增加。这些数据表明3β - HSD活性在月经周期卵泡期增加。提示酶活性增加的主要产物是雄烯二酮。由于雄烯二酮是排卵卵泡产生的主要C19类固醇，并且是雌二醇产生的底物，3β - HSD活性的这种增加可能对卵泡晚期导致排卵的相关变化很重要。
