CC BY 4.0 · Rev Bras Ginecol Obstet 2022; 44(02): 125-132
DOI: 10.1055/s-0042-1742317
Original Article
High Risk Pregnancy

Expression of Endothelin-1 and Endothelial Nitric Oxide Synthase in Normal and Preeclamptic Placentae

Expressão de endotelina-1 e de óxido nítrico sintase endotelial em placentas normais e pré-eclâmpticas
1   Department of Physiology, University of Medicine 2, Yangon, The Republic of the Union of Myanmar
,
1   Department of Physiology, University of Medicine 2, Yangon, The Republic of the Union of Myanmar
,
1   Department of Physiology, University of Medicine 2, Yangon, The Republic of the Union of Myanmar
,
2   Physiology Unit, Universiti Sultan Zanial Abidin, Kuala Terengganu,Terengganu, Malaysia
,
1   Department of Physiology, University of Medicine 2, Yangon, The Republic of the Union of Myanmar
› Author Affiliations

Abstract

Objective To investigate the expression of endothelin-1 (ET-1) and endothelial nitric oxide (NO) synthase (eNOS) in normal and preeclamptic (PE) placentae.

Methods The present cross-sectional analytical study was performed in normal and PE primigravidae (n = 10 in each group) who were admitted to the North Okkalapa General and Teaching Hospital from February 2019 to February 2020. Serum samples were collected immediately before delivery, and placental tissues were collected immediately after emergency or elective cesarean section. The expression of placental eNOS was measured by western blot, and the levels of ET-1 in placental tissue homogenates and in the serum were measured by enzyme-linked immunosorbent assay (ELISA).

Results The PE group had significantly higher serum levels of ET-1 (median: 116.56 pg/mL; IQR: 89.14–159.62 pg/mL) than the normal group (median: 60.02 pg/mL; IQR: 50.89–94.37 pg/mL) (p < 0.05). However, statistically significant differences were not observed in the levels of ET-1 in placental tissue homogenates between normal and PE placentae (median: 0.007 pg/µg of total protein; IQR: 0.002–0.0123 pg/µg of total protein; and median: 0.005 pg/µg of total protein; IQR: 0.003–0.016 pg/µg of total protein respectively). The median and IQR values of relative placental eNOS expression were significantly higher in the PE group than in the normal group (p < 0.05). The serum levels of ET-1 level were not significantly correlated with placental ET-1 expression, and neither there was a significant correlation between placental ET-1 and eNOS expression in any of the groups.

Conclusion The serum levels of ET-1 were significantly higher in PE pregnant women compared with normal pregnant women, while the ET-1 levels of placental tissue homogenates were not significantly different. Serum ET-1 rather than placental ET-1 might play a major role in the pathogenesis of PE.

Resumo

Objetivo Investigar a expressão da endotelina-1 (ET-1) e da óxido nítrico sintase endotelial (endothelial nitric oxide synthase, eNOS, em inglês) em placentas normais e com pré-eclâmpsia (PE).

Métodos Este estudo transversal e analítico foi realizado em primigestas normais e com PE (n = 10 em cada grupo) internadas no Hospital Geral e das Clínicas de North Okkalapa entre fevereiro de 2019 e fevereiro de 2020. Amostras de soro foram coletadas imediatamente antes do parto, e os tecidos placentários foram coletados imediatamente após cesariana de emergência ou eletiva. A expressão da eNOS da placenta foi medida por western blot, e os níveis de ET-1 nos homogenatos de tecidos placentários ET-1 e no soro foram medidos por ensaio de imunoabsorção enzimática.

Resultados O grupo com PE apresentou níveis séricos de ET-1 significativamente mais altos (mediana: 116,56 pg/mL; IIQ: 89,14–159,62 pg/mL) do que o grupo normal (mediana: 60,02 pg/mL; IIQ: 50,89–94,37 pg/mL) (p < 0,05). No entanto, não foi observada diferença significativa no nível ET-1 dos homogenatos de tecidos placentários entre placentas normais e com PE (mediana: 0,007 pg/µg de proteína total; IIQ: 0,002–0,0123 pg/µg de proteína total; e mediana: 0,005 pg/µg de proteína total; IIQ: 0,003–0,016 pg/µg de proteína total, respectivamente). Os valores da mediana e do IIQ da expressão relativa da eNOS placentária foram significativamente maiores no grupo com PE do que no grupo normal (p < 0,05). O nível sérico de ET-1 não estava significativamente correlacionado com a expressão placentária de ET-1, e tampouco houve correlação significativa entre as expressões placentária de ET-1 e de eNOS em nenhum dos grupos.

Conclusão Os níveis séricos de ET-1 foram significativamente maiores em gestantes com PE em comparação com gestantes normais, ao passo que os níveis de ET-1 dos homogenatos de tecidos placentários não foram significativamente diferentes. A ET-1 sérica, em vez da ET-1 placentária, pode desempenhar um papel importante na patogênese da EP.

Contributors

All authors were involved in the design and interpretation of the analyses, contributed to the writing of the manuscript, and read and approved the final manuscript.




Publication History

Received: 13 January 2021

Accepted: 11 November 2021

Article published online:
25 February 2022

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