Hsu C Y, Chang L T, Yu N W
Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Proc Natl Sci Counc Repub China B. 1988 Apr;12(2):84-7.
In a previous RIA study we found that cyanoketone (CK) inhibited ovarian E2 secretion of tadpoles in vitro and that this inhibition effect was through inactivation of delta 5-3 beta-HSD activity. A complete 100% inhibition was expected at a CK dosage of 0.1 microgram/ml of the medium, but, instead, it was 85%. The discrepancy might be due to the fact that the previous experiments did not preincubate the ovaries with CK in order to get rid of the residual E2. To this end, the present study was designed. Tadpole ovaries of Rana catesbeiana were preincubated with CK of a dosage of 0, 0.001, 0.01, 0.1, 1, or 10 micrograms/ml of the KRbb medium for 30 min. The media were discarded. Fresh media with the same series of CK doses were added to the ovaries and were incubated again for 6 hr. The media were collected for RIA of estrogen. The results showed the same tendency of estrogen inhibition as the previous study. However, a maximal inhibition effect of 95% was obtained at the dose of 0.1 microgram/ml. Therefore, the difference between non-preincubation of the previous experiments and preincubation of the present study does exist as we predicted.
在之前的一项放射免疫分析（RIA）研究中，我们发现氰乙酮（CK）在体外可抑制蝌蚪卵巢的E2分泌，且这种抑制作用是通过使δ5-3β-羟类固醇脱氢酶（delta 5-3 beta-HSD）活性失活来实现的。预计在培养基中CK剂量为0.1微克/毫升时会出现完全100%的抑制，但实际却是85%。这种差异可能是由于之前的实验没有用CK对卵巢进行预孵育以去除残留的E2。为此，设计了本研究。用剂量为0、0.001、0.01、0.1、1或10微克/毫升的KRbb培养基中的CK对牛蛙蝌蚪卵巢进行30分钟预孵育。弃去培养基。向卵巢中加入含有相同系列CK剂量的新鲜培养基，并再次孵育6小时。收集培养基用于雌激素的放射免疫分析。结果显示出与之前研究相同的雌激素抑制趋势。然而，在0.1微克/毫升的剂量下获得了95%的最大抑制效果。因此，正如我们所预测的，之前实验的未预孵育与本研究的预孵育之间确实存在差异。
