Nitric Oxide and Antioxidant Enzymes in Venous and Cord Blood of Late Preterm and Term Omani Mothers

Abstract

This study assessed the role of oxidative stress in parturition in Omani mothers following growing reports that late preterm neonates were at greater risk than term neonates of perinatal death. Methods: Venous blood samples were collected during labour, and cord (neonatal) blood samples were taken after childbirth in late preterm and term from women at Sultan Qaboos University Hospital, Oman. Plasma nitric oxide (NO) concentrations, erythrocyte catalase (CAT). Erythrocyte glutathione peroxidase (GPx) activities were measured using spectrophotometric methods. Results: When compared with term mothers, late preterm mothers had markedly higher NO concentrations (µmol/L) 17.1 ± 3.3 versus 11.0 ± 5.5 (P <0.0001), and lower GPx values (U/g Hb) 94.1 ± 12.9 versus 110.4 ± 12.3 (P <0.0001). Late preterm mothers were significantly younger (P = 0.027) than term mothers and had neonates that weighed significantly less (P <0.0001) than term neonates. GPx activity was significantly reduced (P = 0.001) in late preterm neonates as compared to term neonates. CAT showed no change in activity in any comparison. Conclusion: Distinctly higher values of NO and lower GPx activity were found in late preterm mothers relative to term mothers; also, lower GPx in late preterm neonates relative to term neonates suggested a pro-oxidant-antioxidant imbalance due to the greater oxidative burden in late preterm parturition.

Oxidative Stress and Preterm Birth: An Integrative Review

“…In one study that we reviewed, researchers found alterations in metabolite levels of NO synthesis in maternal blood, venous cord blood, and arterial cord blood at birth in PTB versus TB (Alexandre-Gouabau et al, 2013). In another study, investigators found NO levels measured in maternal blood during labor to be higher in mothers delivering late preterm infants (34-37 weeks of GA) compared to TB (>37 weeks of GA; Abiaka & Machado, 2012). However, they found no differences in the cord blood of PTB compared to TB, suggesting a potential role of dysregulated maternal RNS in the mechanism of late PTB.…”

“…It is a tetrameric ferriheme that decomposes H 2 O 2 to form H 2 O and O 2 (Kodydková, Vávrová, Kocík, & Ž ák, 2014;Pisoschi & Pop, 2015). In the studies we reviewed, researchers found no differences in CAT levels in maternal or cord blood specimens (Abiaka & Machado, 2012;Lázár, Orvos, Sz} oll} osi, & Varga, 2015;Soydinç et al, 2012Soydinç et al, , 2013 and no changes in CAT protein expression in the myometrium tissue (Khan, Matharoo-Ball, & Shaw, 2010) between PTB and TB. However, Soydinc et al (2013) did find lower CAT levels in the vaginal wash fluid in pPROM compared to a matched control group.…”

“…In excess, products of the propagation phase are believed to be cytotoxic and mutagenic to cells. LOOH also can react with metal ions to form LOO and/or alkoxyl radical (LO ), which further exaggerates the propagation phase and exacerbates the (Abiaka & Machado, 2012;Lázár et al, 2015) Western blot (Khan et al, 2010;Soydinc et al, 2013;Soydinç et al, 2012) Ceruloplasmin Spectrophotometry (Micle et al, 2012) GSH Spectrophotometry (Abiaka & Machado, 2012;Lázár et al, 2015;Mustafa et al, 2010;Pathak et al, 2010;Soydinc et al, 2013;Soydinç et al, 2012) Metabolomic approach using LC-HRMS (Alexandre-Gouabau et al, 2013) GPx Western blot (Khan et al, 2010) Spectrophotometry (Abiaka & Machado, 2012;Soydinc et al, 2013;…”

Nrf2 regulates gene-environment interactions in an animal model of intrauterine inflammation: Implications for preterm birth and prematurity

“…Several of these oxidative stress markers have been shown to negatively correlate with birth weight and gestational age of the newborn14. Preterm mothers and neonates also have elevated levels of plasma nitric oxide and lipid peroxidation and decreased glutathione and glutathione peroxidase activity15161736. Antioxidants have been shown to reduce oxidative stress and inflammatory markers in both human gestational tissues and experimental models of PTB.…”

“…Preterm neonates and mothers have elevated levels of markers of oxidative stress, which negatively correlate with birthweight and gestational age at birth121314151617. Elevated levels of markers of oxidative stress have been detected in preterm infants beyond their first 100 days of life18, suggesting that oxidative stress established prenatally may persist throughout infancy.…”