Jóźwik Maciej, Jóźwik Marcin, Milewska Anna Justyna, Battaglia Frederick C, Jóźwik Michał
a Department of Gynecology and Gynecologic Oncology , Medical University of Białystok , Białystok , Poland.
b Department of Gynecology and Obstetrics, Faculty of Medical Sciences , University of Warmia and Mazury , Olsztyn , Poland.
Syst Biol Reprod Med. 2017 Oct;63(5):311-317. doi: 10.1080/19396368.2017.1341962. Epub 2017 Jul 11.
To date we have yet to examine whether amino acid (AA) transport in human ovarian follicles is affected by competitive inhibition. In contrast, transplacental transfer of AAs in late-gestation sheep is characterized by reciprocal competition. This phenomenon has been described by algebraic equations of umbilical uptake of AAs based on maternal arterial concentrations. In the present translational study at a university teaching hospital, we verified whether these equations apply to the transport of AAs from blood to follicular fluid (FF) in human preovulatory follicles. For this purpose we used our data on AA concentrations in blood and FF measured earlier by high-performance liquid chromatography in specimens from 14 patients undergoing oocyte retrieval for in vitro fertilization after controlled ovarian stimulation. The main outcome measure was statistical significance of Spearman correlation coefficients for measured versus calculated concentrations of 8 AAs: isoleucine, leucine, valine, phenylalanine, methionine, threonine, lysine, and arginine. Equations for umbilical uptake provided a highly accurate description of blood-to-FF transport for 7 AAs with the exception of lysine: R ≥ 0.899 (p < 0.0001) for the branched-chain AAs, R = 0.829 (p = 0.0003) for threonine, R = 0.754 (p = 0.0019) for arginine, and R = 0.631 (p = 0.0156) for phenylalanine and methionine. We conclude that these equations indicate competitive inhibition between the AAs studied. Our study strongly suggests that many AA transport systems operating in the placenta should also be active in the cells of the preovulatory follicle. Future studies on AA fluxes in human ovarian follicles must consider possible competitive inhibition.
AA: amino acid; FF: follicular fluid; HPLC: high-performance liquid chromatography.
迄今为止，我们尚未研究人类卵巢卵泡中的氨基酸（AA）转运是否受竞争性抑制的影响。相比之下，妊娠晚期绵羊的氨基酸经胎盘转运具有相互竞争的特征。这种现象已通过基于母体动脉浓度的氨基酸脐部摄取代数方程进行了描述。在一家大学教学医院进行的本转化研究中，我们验证了这些方程是否适用于人类排卵前卵泡中氨基酸从血液到卵泡液（FF）的转运。为此，我们使用了之前通过高效液相色谱法在14例接受控制性卵巢刺激后进行体外受精取卵的患者标本中测量的血液和卵泡液中氨基酸浓度的数据。主要观察指标是8种氨基酸（异亮氨酸、亮氨酸、缬氨酸、苯丙氨酸、蛋氨酸、苏氨酸、赖氨酸和精氨酸）实测浓度与计算浓度的Spearman相关系数的统计学显著性。脐部摄取方程对除赖氨酸外的7种氨基酸的血液到卵泡液转运提供了高度准确的描述：支链氨基酸的R≥0.899（p<0.0001），苏氨酸的R = 0.829（p = 0.0003），精氨酸的R = 0.754（p = 0.0019），苯丙氨酸和蛋氨酸的R = 0.631（p = 0.0156）。我们得出结论，这些方程表明所研究的氨基酸之间存在竞争性抑制。我们的研究强烈表明，许多在胎盘中起作用的氨基酸转运系统在排卵前卵泡细胞中也应是活跃的。未来关于人类卵巢卵泡中氨基酸通量的研究必须考虑可能的竞争性抑制。
AA：氨基酸；FF：卵泡液；HPLC：高效液相色谱法
