English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Endothelin (ET)-1, a potent vasoconstrictor and smooth muscle mitogen, is produced from its precursor, preproET-1, by endothelin-converting enzyme (ECE)-1 activity. ET-1 may bind to two receptors, ET A and ET B , that mediate vasoconstriction and vasodilation in the ovine fetal lung, respectively. ET-1 contributes to high pulmonary vascular resistance in experimental perinatal pulmonary hypertension induced by ligation of the ductus arteriosus in the fetal lamb. Physiological studies in this model have demonstrated enhanced ET A - and diminished ET B -receptor activities and a threefold increase in lung immunoreactive ET-1 protein content. We hypothesized that increased ET production and an imbalance in receptor expression would favor vasoconstriction and smooth muscle cell hypertrophy in pulmonary hypertension and may be partially due to alterations in gene expression. To test this hypothesis, we studied lung mRNA expression of preproET-1, ECE-1, and the ET A and ET B receptors in normal and hypertensive fetal lambs. Total RNA was isolated from whole lung tissue in normal late-gestation fetuses (135 ± 3 days; 147 days = term) and from animals with pulmonary hypertension after ductus arteriosus ligation for 8 days (134 ± 4 days). Ductus arteriosus ligation increased right ventricular hypertrophy [control 0.56 ± 0.02 vs. hypertension 0.85 ± 0.05; right ventricle/(left ventricle + septum); P &lt; 0.05]. Northern blot analysis was performed using cDNA probes and was normalized to the signal for 18S rRNA. We found a 71 ± 24% increase in steady-state preproET-1 mRNA ( P &lt; 0.05) and a 62 ± 5% decrease in ET B mRNA ( P &lt; 0.05) expression in ductus arteriosus ligation. ECE-1 and ET A -receptor mRNA expression did not change. We conclude that chronic intrauterine pulmonary hypertension after ductus arteriosus ligation increases steady-state preproET-1 mRNA and decreases ET B -receptor mRNA without changing ECE-1 mRNA or ET A -receptor mRNA expression. These findings suggest that increased ET-1 production and decreased ET B -receptor expression may contribute to increased vasoconstrictor tone in this experimental model of neonatal pulmonary hypertension.

Increased lung preproET-1 and decreased ETB-receptor gene expression in fetal pulmonary hypertension

Increased lung preproET-1 and decreased ET_B-receptor gene expression in fetal pulmonary hypertension