Kreydiyyeh Sawsan Ibrahim, Al-Sadi Rana
Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon.
J Interferon Cytokine Res. 2002 Oct;22(10):1041-8. doi: 10.1089/107999002760624279.
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.
在大鼠肠道和肾上皮细胞中研究了白细胞介素-1β（IL-1β）对尿流率以及Na(+)/K(+)-ATP酶活性和表达的影响。与对照组相比，该细胞因子产生了显著的利尿作用，使尿流率增加了约10倍。这种作用被认为是该细胞因子在文献中所述的利钠作用的继发效应。另一方面，我们之前已经表明IL-1β抑制空肠对葡萄糖的吸收。由于钠排泄和葡萄糖吸收均依赖于Na(+)/K(+)-ATP酶活性，因此研究了该细胞因子对肾和肠泵的作用。IL-1β以剂量依赖的方式抑制绒毛和空肠隐窝细胞以及肾髓质和皮质细胞中Na(+)/K(+)-ATP酶的活性。蛋白质印迹分析显示该酶的蛋白质表达降低，放射性标记的哇巴因结合试验证实了这一点。结果表明IL-1β的利尿和利钠作用及其对葡萄糖吸收的抑制作用均归因于肾和空肠中Na(+)/K(+)泵的下调。
