Progesterone is a natural steroid hormone that has many functions in the organism, regulating the work of non-reproductive and reproductive tissues. The article describes the mechanism of hormone effects. The data about genomic and nongenomic effects of progesterone through intracellular and plasma membrane´s receptors are presented. Specific effects of progesterone in various tissues depend on the ratio of receptors and their coregulators. Progesterone is the main hormone of pregnancy; therefore a large section is devoted to its action in that period. The hormone functions include participation in the ovulation and implantation processes, decidual transformation of endometrial tissue, inhibition of uterine contractility, suppression of the mother immune system, the accumulation of nutrients for fetal growth, development of the mammary glands, co-operation in the development of the embryo tissues. Several mechanisms of preventing myometrial contractility and transition mechanism of maternal immune system to function in conditions of pregnancy are considered in detail. Besides the hormone role during pregnancy, the regulation of other important functions of the human body is described.

МЕТАБОЛИЗМ ПРОГЕСТЕРОНА В ПЛАЦЕНТЕ (ОБЗОР ЛИТЕРАТУРЫ) И.В.Довжикова, М.Т.ЛуценкоФедеральное государственное бюджетное научное учреждение «Дальневосточный научный центр физиологии и патологии дыхания », 675000, г. Благовещенск, ул. Калинина, 22 РЕЗЮМЕ В статье представлены современные данные о метаболизме прогестерона в плаценте. Рассмот-рены ферменты, принимающие участие в преобра-зовании гестагенов: альдокеторедуктазы (AKR1D1, AKR1C1, AKR1C2, AKR1C3, SRD5A1, SRD5A2), 3β-и 17β-гидроксистероиддегидрогеназы. Изложены существующие в настоящее время мнения об их су-щественной роли в поддержании беременности. Представлены основные метаболиты прогестерона в плаценте -20α-дигидропрогестерон и 5α-дигидро-прогестерон. Кроме этого, особое внимание в статье уделено двум другим активно изучаемым в послед-нее время метаболитам: 5β-дигидропрогестерону и аллопрегненолону. Подчеркнута их центральная роль: 5β-дигидропрогестерон поддерживает тонус миометрия в состоянии покоя, аллопрегненолон яв-ляется ключевым нейроактивным стероидом в пе-риод жизни плода. Сделан вывод о необходимости дальнейшего исследования метаболизма прогесте-рона в плаценте.Ключевые слова: прогестерон, плацента, фер-менты метаболизма прогестерона. Respiration, 22 Kalinina Str., Blagoveshchensk, 675000, Russian Federation Current data on progesterone metabolism in placenta are presented in the article. Enzymes involved in the conversion of gestogens: aldo-keto reductases (AKR1D1, AKR1C1, AKR1C2, AKR1C3, SRD5A1, SRD5A2), 3β-and 17β-hydroxysteroid dehydrogenases were studied. Existing opinions on their essential role in the maintenance of pregnancy were presented. The main metabolites of progesterone in placenta, namely 20α-dihydroprogesterone and 5α-dihydroprogesterone were presented. In addition, special attention was paid to other two metabolites actively studied at present: 5β-dihydroprogesterone and allopregnenolone. Their central role was emphasized: 5β-dihydroprogesterone maintains myometrium tonus at quiescent interval, and allopregnenolon is a key neuroactive steroid during the fetal life. It was concluded that further research is needed to study progesterone metabolism in placenta. SUMMARY PROGESTERONE METABOLISM IN PLACENTA (REVIEW) I.V.Dovzhikova, M.T.Lutsenko Far Eastern Scientific Center of Physiology and Pathology of

The article analyzes the importance of estrogen during pregnancy. The mechanism of hormones effects is summarized. The effect of estrogen on utero-placental blood flow, its necessity to run tissue morphogenesis in placenta and uterus, the impact on other steroid and protein hormones production, stimulating effect on 11β-hydroxysteroid dehydrogenase work, regulation of LDL expression are studied. The growth factors that are mediators of estrogen are shown. There was made a conclusion that in early pregnancy estrogens contribute to morphological and functional growth, development and differentiation of placenta and in the second half of pregnancy estrogens stimulate functional maturation. Furthermore, hormones play an important role in the development of lung, kidney, liver, ovarian follicles, fetal bone and promote the formation of different changes in the mother necessary for the maintenance of pregnancy.

The aim of the study is to define the role of abnormalities in the formation of estriol hormones in the development of hormonal dysfunction of fetoplacental system. There were examined 39 placentas from women with exacerbation of chronic cytomegalovirus infection at the third trimester of pregnancy and IgG antibody titer 1:1600 and 30 placentas from women with latent CMV infection and titer 1:400. The activity of androstenedione dehydrogenase was found out with histochemical method on cryostat sections of freshly frozen tissues of placentas by Lloyd’s method. The assessment of intensiveness of histochemical reaction was done with cytophotometric method by Scion program. Estradiol in homogenate of placenta was measured with immune-enzyme method. The quantity of nuclei of placenta syncytiotrophoblast in the state of apoptosis was done with cytophotometric method on paraffin sections stained by ISEL method. By the results of the study the exacerbation of CMV infection at the third trimester of pregnancy leads to the decrease of intensiveness of histochemical reaction in placentas to androstenedione dehydrogenase till 32.1±2.88 pixel/mcm2 (at the latent course it is 54.2±4.31 pixel/mcm2, р<0.001), and in homogenate of placenta to the decrease of estradiol till 18443.2±117.53 pmole/l (at the latent course of the disease it is 28977.7±158.13 pmole/l, p<0.001), on paraffin sections in syncytiotrophoblast by the increase of nuclei number in the state of apoptosis till 5.0±0.03% (at latent course of the disease it is 1.2±0.001%, р<0.001) and vacuole formation, which leads to destructive damages of syncytiotrophoblast cytoplasm. The obtained results prove that the exacerbation of CMV infection at the third trimester of pregnancy causes the decrease of estriol hormones formation, which is accompanied by the damage of morphostructure and exchange processes in cell elements of placenta.