Wiener M, Reiner J M
Mech Ageing Dev. 1978 Jun;7(6):445-53. doi: 10.1016/0047-6374(78)90085-4.
Dilution of tissue fractions from human placenta resulted in an increase in the specific activites of 3 beta-hydroxy-delta 5-steroid dehydrongease and of 20 alpha-hydroxysteroid dehydrogenase. The apparent Ks and V max of 3 beta-hydroxy-delta 5-steroid dehydrogenase were altered. It is postulated that this dilution effect is caused by the presence in the placenta of an endogenous inhibitor of steroid synthesis which may be important in the regulation of steroid output by this organ. A mathematical model of such an inhibitor corresponds well to the experimental results.
人胎盘组织部分的稀释导致3β-羟基-δ5-类固醇脱氢酶和20α-羟基类固醇脱氢酶的比活性增加。3β-羟基-δ5-类固醇脱氢酶的表观Ks和Vmax发生了改变。据推测，这种稀释效应是由胎盘中存在的类固醇合成内源性抑制剂引起的，该抑制剂可能在该器官类固醇输出的调节中起重要作用。这种抑制剂的数学模型与实验结果非常吻合。
