Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endothelin (ET) is the most potent endogenous vasoconstrictory substance known. There are three structurally and pharmacologically separate endothelial isopeptides in humans; Endothelin-1 is exclusively produced in the vascular endothelium. It seems likely that ET acts as a local paracrine signal rather than a circulating hormone. The synthesis and release of ET is stimulated among others by hypoxia, thrombin and endotoxin. Its effects are mediated by specific, membrane-bound receptors, which are detectable in high concentrations in the fetoplacental tissue. ET-1 causes an initial transient fall in blood pressure, followed by a strong, long-lasting increase in peripheral resistance and blood pressure. Plasma ET-1 levels are increased in preeclampsia as compared to those of normal pregnancies, and do not correlate with mean arterial blood pressure and degree of proteinuria. In umbilical cord blood ET-1 concentrations are 2.5-10-fold higher than those of maternal plasma. Determination of plasma ET is unlikely to be of value in the prediction of the disease. ET-1 induces an increased synthesis of vasodilatory prostaglandins (PGI2, PGE2) and an increased production of endothelial-derived relaxing factor (EDRF); thromboxane concentrations in blood are elevated by thrombin-induced activation of platelets. In animal models ET-1 causes an activation of plasmatic coagulation with consecutive hypercoagulability. In preeclampsia ET may play an important role in the regulation of the endothelial balance. Future therapeutic approaches may include the development of effective ET-antibodies or of inhibitors of the endothelin-converting enzyme.
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PMID:[Endothelin--possible significance in pregnancy and hypertensive pregnancy]. 823 57

The protective effects of phosphoramidon, a dual inhibitor of endothelin-converting enzyme and neutral endopeptidase (E.C. 24.11), on renal function in ischemic acute renal failure were investigated in anesthetized rats. Intravenous infusion of phosphoramidon (0.03 and 0.1 mg/kg per min) significantly suppressed tubular sodium wasting (measured by fractional excretion of sodium) and proteinuria in the postischemic kidney without modifying functional parameters in the contralateral normal kidney. Phosphoramidon (0.1 mg/kg/min) was associated with increased glomerular filtration in the ischemic kidney. In comparison, SCH 42354, a highly selective inhibitor of neutral endopeptidase at 0.3 mg/kg/min, did not inhibit endothelin-converting enzyme or afford renal protection. The data suggest that the protective action of phosphoramidon against ischemic acute renal failure is most likely mediated by inhibition of endothelin formation.
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PMID:Attenuation of ischemic acute renal failure by phosphoramidon in rats. 841 69

Hypertension and renal injury are off-target effects of sunitinib, a tyrosine kinase receptor inhibitor used for the treatment of various tumor types. Importantly, these untoward effects are accompanied by activation of the endothelin system. Here, we set up a study to explore the dose dependency of these side effects. Normotensive Wistar Kyoto rats were exposed to 3 different doses of sunitinib or vehicle. After 8 days, rats were euthanized. Telemetrically measured blood pressure rose dose dependently, from 13 to 30 mm Hg. Proteinuria was present at all doses, but a rise in cystatin C occurred only at the intermediate and high doses. Compared with vehicle circulating endothelin-1 increased dose dependently, whereas 24-hour urinary endothelin excretion decreased. Light and electron microscopy revealed glomerular endotheliosis and ischemia with the intermediate and high doses of sunitinib but completely absent histological abnormalities with the low dose. Podocyte number per glomerular circumference did not change. Glomerular nephrin, Neph1, podocin, and endothelin-converting enzyme gene expression were downregulated in a dose-dependent manner. We conclude that the sunitinib-induced rise in blood pressure requires lower doses than its induction of renal function impairment and that functional changes in glomerular filtration barrier contribute to the occurrence of proteinuria, given the lack of histopathologic changes with the low dose of sunitinib.
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PMID:Greater Sensitivity of Blood Pressure Than Renal Toxicity to Tyrosine Kinase Receptor Inhibition With Sunitinib. 2619 84

The endothelins comprise three structurally similar 21-amino acid peptides. Endothelin-1 and -2 activate two G-protein coupled receptors, ETA and ETB, with equal affinity, whereas endothelin-3 has a lower affinity for the ETA subtype. Genes encoding the peptides are present only among vertebrates. The ligand-receptor signaling pathway is a vertebrate innovation and may reflect the evolution of endothelin-1 as the most potent vasoconstrictor in the human cardiovascular system with remarkably long lasting action. Highly selective peptide ETA and ETB antagonists and ETB agonists together with radiolabeled analogs have accurately delineated endothelin pharmacology in humans and animal models, although surprisingly no ETA agonist has been discovered. ET antagonists (bosentan, ambrisentan) have revolutionized the treatment of pulmonary arterial hypertension, with the next generation of antagonists exhibiting improved efficacy (macitentan). Clinical trials continue to explore new applications, particularly in renal failure and for reducing proteinuria in diabetic nephropathy. Translational studies suggest a potential benefit of ETB agonists in chemotherapy and neuroprotection. However, demonstrating clinical efficacy of combined inhibitors of the endothelin converting enzyme and neutral endopeptidase has proved elusive. Over 28 genetic modifications have been made to the ET system in mice through global or cell-specific knockouts, knock ins, or alterations in gene expression of endothelin ligands or their target receptors. These studies have identified key roles for the endothelin isoforms and new therapeutic targets in development, fluid-electrolyte homeostasis, and cardiovascular and neuronal function. For the future, novel pharmacological strategies are emerging via small molecule epigenetic modulators, biologicals such as ETB monoclonal antibodies and the potential of signaling pathway biased agonists and antagonists.
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PMID:Endothelin. 2695 45