Role of the Nitric Oxide (NO) in the Regulation of Steroidogenesis in Placenta During Physiological Pregnancy and Preeclampsia (Experimental Study)

Abstract

The aim of the study was to establish the role of nitric oxide (NO) in the regulation of steroidogenesis in the placenta during physiological pregnancy and experimental preeclampsia (PE) in rats. EPR centers of the placenta, free NO and its metabolites were determined by the Electron Paramagnetic Resonance (EPR) method. At the last stage of pregnancy in the EPR spectra of the rats’ placenta with PE alterations of the signals intensity of mitochondrial steroidogenic electron transport proteins were detected: the FeS-centers of adrenodoxin decreased, the ferricytochrome P-450 increased, the free NO content decreased, and the complexes of NO with heme (HbNO) and non-heme iron (FeSNO) were detected. These data indicate the violation of placental steroidogenesis, which is confirmed by a decrease in the level of progesterone in blood. Therefore, the nitrosylation of mitochondrial proteins is an important redox-dependent mechanism of regulation of the intensity of steroidogenesis.

Nitric oxide synthase and its function in animal reproduction: an update

“…At this stage, eNOS mRNA expression and etrahydrobiopterin reduction (BH4/ BH2 ratio) were increased by low-dose N-acetylcysteine. Therefore, placental progesterone levels and eNOS expression are correlated with environmental organophosphates (Rivero Osimani et al, 2016;Sanikidze et al, 2019;Ding et al, 2021;Ding et al, 2021).…”

“…L-arginine +3/2 NADPH + H + + 2O 2 = citrulline + NO + 3/ 2 NADP and is catalyzed by NOS (Sanikidze et al, 2019;Luo et al, 2021). NO can activate sGC, a common NO sensor in mammals, through the L-arginine-NO-cGMP pathway (Hattori and Tabata, 2006;Lind et al, 2017;Iova et al, 2023).…”