Van Voorhis B J, Moore K, Strijbos P J, Nelson S, Baylis S A, Grzybicki D, Weiner C P
Department of Obstetrics and Gynecology, University of Iowa College of Medicine, Iowa City 52242-1080, USA.
J Clin Invest. 1995 Dec;96(6):2719-26. doi: 10.1172/JCI118339.
Nitric oxide is reportedly involved in the regulation of several ovarian processes, yet the isoforms of nitric oxide synthase (NOS) expressed in the ovary are unknown. Our purpose was to identify and localize NOS isoenzymes in the rat ovary and to examine++ if mRNA expression of NOS isoenzymes change after gonadotropin stimulation. Using reverse transcriptase-PCR, we demonstrated that inducible (iNOS) and endothelial (eNOS), but not neuronal, NOS mRNAs are expressed in the ovary. In a gonadotropin-stimulated rat model, unstimulated ovaries had the highest levels of iNOS mRNA as quantified by ribonuclease protection assay. After gonadotropin injection, iNOS mRNA declined to undetectable levels in ovaries containing ovulatory follicles before increasing slighty in ovaries containing copora lutea. In situ hybridization studies localized iNOS to granulosa cells of secondary follicles and small antral follicles. Western blots of unstimulated ovaries demonstrated iNOS protein. In contrast to iNOS, eNOS mRNA levels, determined by quantitative PCR, increased after gonadotropin stimulation and peaked in ovaries containing ovulatory follicles before declining in the luteal phase. eNOS protein was localized to blood vessels in the ovary by immunohistochemistry. We conclude that two isoforms of NOS are expressed in the ovary and the mRNA levels for these isozymes are differentially regulated.
据报道，一氧化氮参与多种卵巢生理过程的调节，然而卵巢中表达的一氧化氮合酶（NOS）同工型尚不清楚。我们的目的是鉴定和定位大鼠卵巢中的NOS同工酶，并研究促性腺激素刺激后NOS同工酶的mRNA表达是否发生变化。利用逆转录聚合酶链反应，我们证明卵巢中表达诱导型（iNOS）和内皮型（eNOS）而非神经元型NOS的mRNA。在促性腺激素刺激的大鼠模型中，通过核糖核酸酶保护试验定量，未受刺激的卵巢中iNOS mRNA水平最高。注射促性腺激素后，在含有排卵卵泡的卵巢中，iNOS mRNA下降至检测不到的水平，然后在含有黄体的卵巢中略有增加。原位杂交研究将iNOS定位在次级卵泡和小窦状卵泡的颗粒细胞中。未受刺激的卵巢的蛋白质免疫印迹显示有iNOS蛋白。与iNOS相反，通过定量聚合酶链反应测定，促性腺激素刺激后eNOS mRNA水平升高，并在含有排卵卵泡的卵巢中达到峰值，然后在黄体期下降。通过免疫组织化学将eNOS蛋白定位在卵巢血管中。我们得出结论，卵巢中表达两种NOS同工型，这些同工酶的mRNA水平受到不同的调节。
