title: Interleukin-1beta increases urine flow rate and inhibits protein expression of Na(+)/K(+)-ATPase in the rat jejunum and kidney.
abstract: The effect of interleukin-1beta (IL-1beta) on urine flow rates and Na(+)/K(+)-ATPase activity and expression was studied in rat intestinal and renal epithelia. The cytokine produced a significant diuretic effect and increased urine flow rate by around 10-fold compared with the control. This effect was considered to be secondary to the well-documented natriuretic effect of the cytokine described in the literature. On the other hand, we have shown previously that IL-1beta inhibits glucose absorption from the jejunum. As sodium excretion and glucose absorption are both dependent on Na(+)/K(+)-ATPase activity, the effect of the cytokine on the renal and intestinal pump was investigated. IL-1beta inhibited, in a dose-dependent manner, the activity of Na(+)/K(+)-ATPase in villus and crypt jejunal cells and in medullary and cortical kidney cells. Western blot analysis revealed a decrease in the protein expression of the enzyme, which was confirmed by the radiolabeled ouabain binding assay. The results suggest that the diuretic and natriuretic effect of IL-1beta and its inhibitory effect on glucose absorption are all due to downregulation of the Na(+)/K(+) pump in the kidney and jejunum.
authors.affiliation: Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon. Sawkreyd@aub.edu.lb
authors.forename: Sawsan Ibrahim
authors.initials: SI
authors.lastname: Kreydiyyeh
authors.forename: Rana
authors.initials: R
authors.lastname: Al-Sadi
mesh_terms: D000818:Animals; D004231:Diuresis / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D007583:Jejunum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D010042:Ouabain / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D007375:Interleukin-1; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase