ROLE OF ARGININE IMBALANCE IN THE DEVELOPMENT OF PLACENTAL INSUFFICIENCY
Objective. To study the metabolic features of arginine and the placental production of its derivatives during physiological pregnancy and placental insufficiency. Subjects and methods. The study was conducted in 36 women with placental insufficiency, who were divided into 2 groups depending on the term of labor (36—37 and 39— 40 weeks of gestation) and in 20 females with uncomplicated pregnancy and labor (a control group). Biochemical methods and electron paramagnetic resonance spectrometry were applied. Results. Significant changes were found in the levels of arginine and proline, the activity of arginase and nitric oxide synthase, and the rate of production of nitric oxide, peroxynitrite, nitrosothyrosine, and nitrosoglutathione in the placenta in its insufficiency. The degree of modification of the metabolites under examination was more pronounced in the placenta of women with complicated pregnancy during preterm labor than in that of women with full-term labor. There were relationships between the activity of enzymatic processes and the level of substrates and end products of respective biochemical reactions.