ИСТИНА

It is well-known that endometriosis leads to the ovarian reserve reduction as a result of both disruption of folliculogenesis and involuntary resection of healthy ovarian tissue surrounding endometriotic cysts during surgical treatment. Oxidative stress plays a significant role in the pathogenesis of ovarian reserve reduction. Possible oxidative stress markers in endometriosis are well studied, however, the data on sources of reactive oxygen species (ROS) and their impact on ovarian reserve in endometriosis and endometriotic cysts currently is insufficient. Thus, the aim of our study is to assess the contribution of ROS homeostasis disturbances in reducing the ovarian reserve in patients with endometriotic ovarian cysts and to identify the source of ROS in endometriotic cysts. The experimental group consisted of patients with unilateral and bilateral endometriotic cysts. The control group included patients with benign ovarian tumors (including teratomas and serous cystadenomas). During a surgical intervention a sample (approximately 30 μg) of ovarian tissue in the immediate proximity of the formation was taken. In unilateral lesions, sample of contralateral ovarian tissue was taken. We performed chemiluminescence tests with NADH mitochondrial respiration stimulus to assess the pro-oxidant capacity and the ROS-producing capacity of the ovarian tissue. The intensity of chemiluminescence (Icl) during aeration with an oxygen-containing gas mixture was comparable for ovarian tissue from an ovary containing an endometriotic cyst and ovarian tissue not containing an endometrioma (approximately 0.51). With the introduction of NADH was added there was a marked increase in Icl in the control group, however, in the ovarian tissue samples form ovaries containing endometriotic cysts, the radical-producing capacity in response to the NADH-stimulus was significantly lower. Moreover, there was a negative correlation of the NADH-induced response and the size of the ovarian cyst. NADH-stimulated Icl in ovaries containing cysts ≤ 3 cm and > 3 cm in diameter was 3.1 ± 0.6 and 0.83 ± 0.15 respectively. The Spearman correlation coefficient was -0.82 (p = 0.001). To address the correlation between the level of anti-Mullerian hormone (AMH) levels and the radical producing ability of ovarian tissue, we calculated the average stimulation coefficient (SC = INADH / Iaer). for both ovaries. There was a direct correlation between the stimulation coefficient and the level of AMH (r = 0.67, p = 0.03). The data mentioned above indicates suggests the mitochondrial resource depletion in ovarian tissue with endometriotic cysts. Perhaps the mitochondrial respiration suppression in ovarian tissue due to the effect of ROS produced by the contents of the endometriotic cyst is one of the main causes for the ovarian reserve reduction in ovaries containing endometriotic cysts