Goncharov B F, Skoblina M N
Ontogenez. 2014 Mar-Apr;45(2):102-11.
Incubation of sturgeon full-grown ovarian follicles in amphibian Ringer solution with increased sodium bicarbonate concentration results in "spontaneous" oocyte maturation. Addition of sodium bicarbonate to diluted Leibovitz medium also induces maturation of follicle-enclosed oocytes. Effective threshold concentration of sodium bicarbonate depends on the composition of culture medium and, especially, on the physiological state of follicle-enclosed oocytes. As evidenced by experiments with actinomycin D, oocyte maturation induced by bicarbonate ions does not depend on RNA synthesis. An attempt was made to elucidate the involvement of steroidogenesis in bicarbonate ion-induced oocyte maturation. Surprisingly, the inhibitors used, such as aminogluthetimide, diltiazem, andestradiol-17β, not only did not inhibit but also enhanced oocyte maturation. Manual removal of follicle envelopes demonstrated that denuded oocytes retained the ability to mature in a culture medium with increased sodium bicarbonate concentration. However, the range of effective bicarbonate ion concentrations for denuded oocytes is more restricted than for the follicle-enclosed oocytes. A hypothesis of competition of different processes occurring in the ovarian follicle for energy resources is proposed to explain the revealed paradoxical effect of substances affecting steroidogenesis.
将鲟鱼成熟的卵巢卵泡置于碳酸氢钠浓度升高的两栖类任氏液中培养，会导致卵母细胞“自发”成熟。向稀释的莱博维茨培养基中添加碳酸氢钠也能诱导卵泡包裹的卵母细胞成熟。碳酸氢钠的有效阈值浓度取决于培养基的成分，尤其取决于卵泡包裹的卵母细胞的生理状态。放线菌素D实验表明，碳酸氢根离子诱导的卵母细胞成熟不依赖于RNA合成。人们试图阐明类固醇生成在碳酸氢根离子诱导的卵母细胞成熟中的作用。令人惊讶的是，所使用的抑制剂，如氨鲁米特、地尔硫䓬和17β -雌二醇，不仅没有抑制反而增强了卵母细胞成熟。手动去除卵泡被膜表明，去膜卵母细胞在碳酸氢钠浓度升高的培养基中仍保留成熟能力。然而，去膜卵母细胞有效碳酸氢根离子浓度范围比卵泡包裹的卵母细胞更窄。提出了一个关于卵巢卵泡中不同过程对能量资源竞争的假说，以解释影响类固醇生成的物质所显示的矛盾效应。
