Renal excretion of endothelin in children

Abstract

Endothelin (ET) is a peptide with profound vasoconstrictive potential. First isolated from porcine endothelial cell supernatant, it is produced also by smooth muscle, epithelial and circulating cells. Besides vasoconstriction, a wide spectrum of biological activities of ET (via activation of membrane receptors) has been described. These include regulation of other hormones and neurotransmitters, cellular growth and proliferation, bronchoconstriction, and, in the kidney, natriuresis and water diuresis. ET exerts its effects mainly in an autocrine and paracrine fashion. A high concentration of ET is found in urine, compared with plasma originating mainly from the kidney itself. In this review we focus on the role of urinary excretion of ET in children. ET excretion was determined under different physiological and pathological conditions. In premature infants and newborns, the daily excretion of ET (corrected for body surface) was higher than in older children; it was constant, and comparable to the values in healthy adults after the age of 2 years. Renal ET excretion correlated positively with urine flow in both healthy and sick children. Conditions with tubular and/or collecting duct cell damage, such as severe hypoxia, hemolytic-uremic syndrome, renal transplantation, diabetes mellitus, chronic renal failure, and contrast media cytotoxicity were characterized by elevated urinary excretion of ET. In conclusion, the renal excretion of ET is influenced by several factors, probably reflecting the intrarenal ET production. ET has a low specificity with regard to renal injury.

Endothelin levels in Henoch-Schonlein purpura

“…Different tissues such as the brain, heart, and renal endothelial cells have the capacity to synthesize ET-1. Respiratory and renal tubular cells are able to synthesize ET-1 [11,13,22,23,31,32]. Although, in our study, the ET-1 levels in the acute phase were significantly higher than in the remission phase and the controls (Table 4), blood pressure was not above the 95th percentile for the respective age.…”

“…Plasma ET-1 levels have been reported high in atherosclerosis, systemic and pulmonary hypertension, and vasculitis (such as Takayasu arteritis, Bürger disease, Raynauld phenomenon, Behçet disease, and Kawasaki disease) [13,21,22,23,24,25,26,27,28,29]. Kanno et al [26] determined that plasma ET-1 levels were highest in Takayasu arteritis, Bürger disease, and atherosclerosis.…”

“…Even sub-threshold concentrations of ET-1 will augment vasoconstriction and mitogenic functions of other agents, such as angiotensin II, norepinephrine, and serotonin [13]. The vasoconstrictive effect of ET-1 in the subendothelial tissues is inactivated by nitric oxide [13,22]. ET-1 synthesis is down regulated by vasodilators/anticoagulants, e.g., nitric oxide, prostacyclin, atrial natriuretic peptide, and heparin [13].…”

Pathogenesis of Shiga Toxin-Associated Hemolytic Uremic Syndrome

“…Endothelin is a vasoconstrictive peptide found to be excreted in a variety of renal diseases (159). Abnormally high levels of endothelin have been reported in the serum and urine of patients with HUS (144,147,160), reflecting the degree of renal injury, but possibly contributing to it by vasoactive potency.…”

Using Enteral Sterile Water Feeds for Hypernatremia in Extremely Low Birth-Weight Infants

“…It is elevated during the first few days of life in both term and preterm newborns. 24 Prostaglandins are mediators that can either vasodilate (eg, PGE 1 , PGE 2 , and PGI 2 ) or vasoconstrict (eg, PGF 2 ). Two cyclooxygenase enzymes are present in kidneys: COX-1 and COX-2.…”