Value of nitrogen oxide and cachectine in the pathogenesis of preterm birth

Objective. To investigate whether the impaired production of uterine contractility predictors in the serum from a pregnant woman plays a role in the pathogenesis of preterm birth. Subjects and methods. A total of 134 pregnant women were followed up. Group 1 included 45 women with early preterm birth (PB) at 28-32 weeks and 6 days of gestation; Group 2 consisted of 42 women with PB at 34-36 weeks and 6 days of gestation, and a control group comprised 47 women with normal pregnancy and childbirth. Serum served as the material to be examined. The content of lipocortin (annexin) and the activity of nuclear NF-kB andphospholipase A2 were determined by enzyme immunoassay using kits (Cytimmune systems, USA); VEGFR-A was measured by kits (Red systems, USA). Nitric oxide (NO) levels were estimated using the classical Griess reaction after enzymatic reduction of nitrates to nitrites (designated as NOx in the literature) on a Varian Cary-50 spectrophotometer (USA) at a wavelength of520 nm and was expressed in pkg/ml. The activity of NO synthase (NOS) (EC 1.14.13.39) was assessed by the level of metabolites from L-arginine. Results. The production of cachectine and NO was found to be impaired, which led to elevated intracellular Ca+ levels and caused a lower myometrial contraction. The lower activity of NOS was established to be due to hypoxia during early PB at 28-33 weeks and 6 days and 34-36 weeks and 6 days of gestation. In case of PB at 34-36 weeks and 6 days of gestation, there is an additional factor in reducing the activity of this enzyme, which is a decrease in its amount (synthesis). Conclusion. The findings suggest that the production of cachectine and NO is modified in early and preterm births at 28-33 and 34-36 weeks, respectively. The results of blood cachectine levels in a pregnant woman at different gestational ages make it possible to predict PB in term of its pathogenesis.

uterine contraction bioregulators, preterm birth, endothelial factors, serum