Рак яичников занимает лидирующую позицию среди причин смерти от гинекологических заболеваний

The enhanced chemiluminescence method in combination with mathematical modeling has been used to quantify the antioxidant properties and to study the superoxide dismutase-like (SOD-like) activity of a citrate-stabilized colloid solution of ultrasmall CeO 2 nanoparticles (3 nm) in biochemical models. The trolox (a water-soluble analogue of vitamin E) equivalent antioxidant capacity of a 1 µmol/L CeO 2 sol was 0.049 ± 0.004 µmol/L; thus, the ability of CeO 2 to act as a free radical scavenger is about 20 times lower than that of trolox. The antioxidant activity was estimated by the mathematical modeling method. The free radical scavenging rate constants were 2000 nM –1 min –1 for trolox and k 1 = 300 nM –1 min –1 and k 2 = 4 nM –1 min –1 for cerium dioxide. The SOD-like activity of 1 mmol/L СеО 2 in SOD activity units was 2.00 ± 0.03 nmol/L. Thus, the activity of CeO 2 as a SOD mimetic is about six orders of magnitude lower than the activity of the native enzyme.

Free radical reactions are aconcurrent part of the homeostasis of any system, including reproductive one. The imbalance of free radical production systems and antioxidants leads to pathological consequences, known as oxidative stress. In recent years, there have been actively executed successful studies, in which attempts are made to identify the impact of local oxidative stress in the follicle on the quality of the embryo and the outcome of «in vitro fertilization» (IVF). Despite both the inadequacy of data and the difficulty of comparing them, free radicals and the state of the antioxidant system of the follicular fluid have been proven to have a significant effect on oocyte and embryo development in subsequent IVF.

The aim of the study is to evaluate the antioxidant properties of the follicular fluid with a new chemiluminescent method in women with a reduced ovarian reserve and tubal factor of the infertility, undergoing in vitro fertilization (IVF) procedure, and to compare the obtained data with embryo quality. Material and methods. Samples of the follicular fluid were obtained during oocyte sampling in 16 women with a reduced ovarian reserve and 16 women with a tubal peritoneal factor of the infertility. Patients in both groups were matched for the age, body mass index and hormonal stimulation protocol (short protocol). The antioxidant activity of the follicular fluid was measured by the method of luminol-activated chemiluminescence using 2,2’-azobis (2-amidinopropane) dihydrochloride as a source of radicals. The total antioxidant activity (AOA) and antioxidant activity due to the action of proteins (AOA-b) were determined. Results. The kinetic curve of chemiluminescence of the follicular fluid is similar in shape to the curve of the antioxidant activity of the blood plasma. As in blood plasma, antioxidant activity is caused by uric acid and proteins - albumins and globulins. As a result of the study, three groups of patients were identified, whose AOA significantly differed: patients with low embryo quality and decreased antioxidant activity, AOA 11.4 ± 2.5 mM ascorbate (n = 16); patients with a good quality embryo, AOA 21.4 ± 3.8 mM (n = 10); patients with a low embryo quality and an elevated AOA of 33.7 ± 2.9 mM (n = 6). Conclusions. Based on the comparison of AOA (in ascorbate units) with the quality of the embryo, three areas can be proposed: 1) a zone of reduced antioxidant activity (less than 15 μM, oxidative stress) - these patients had embryos of poor quality; 2) the zone of normal AOA (15-30 μM) - the patients received good quality embryos; 3) zone of increased AOA (more than 30 μM, antioxidant stress) - embryos of poor quality. Thus, it can be assumed that optimal development of embryos in the follicle requires the optimal value of antioxidant activity, since both its reduction (oxidative stress) and increase (antioxidant stress) adversely affect the quality of the embryo and the outcome of IVF. These data correspond to the modern concept that optimal development of the oocyte requires an optimal level of production of reactive oxygen species.