Hiroshi Nonoguchi

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A novel member of the organic anion transporter (OAT) family, Oat5 (Slc22a19), has been reported to transport a naturally occurring mycotoxin, ochratoxin A (OTA). However, neither its endogenous substrate and driving force nor physiological functions have been determined. Herein, we report the functional characterization of rat Oat5 (rOat5), as well as its(More)
BACKGROUND/AIM Hepcidin could be one of the most important regulators for iron metabolism in patients on maintenance hemodialysis (MHD). The factors affecting serum hepcidin levels were evaluated among indexes of anemia, iron metabolism, or inflammation, as well as the dose of erythropoietin. METHODS 198 MHD patients treated with recombinant human(More)
Human organic anion transporter 4 (OAT4) is an apical organic anion/dicarboxylate exchanger in the renal proximal tubules and mediates high-affinity transport of steroid sulfates such as estrone-3-sulfate (E1S) and dehydroepiandrosterone sulfate. Here, two multivalent PDZ (PSD-95/Discs Large/ZO-1) proteins PDZK1 and NHERF1 were examined as interactors of(More)
Stimulation of the release of nitric oxide (NO) in the kidney has been shown to result in renal hemodynamic changes and natriuresis. NO is a potent stimulator of soluble guanylate cyclase, leading to an increase of cyclic GMP. The precise localization of NO synthase and soluble guanylate cyclase in the renal structure is not known. In this study, the(More)
Familial renal hypouricemia with exercise-induced acute renal failure (ARF) is rare. A 45-year-old man presented with abdominal pain, vomiting, and oliguria after severe exercise. The diagnosis was ARF based on high serum creatinine (SCr) level (5.1 mg/dL [451 micromol/L]). Renal function recovered completely within 2 weeks of conservative treatment(More)
Recent studies revealed that angiotensin II (Ang II) interacts with two pharmacologically different subtypes of cell surface receptors. Type I Ang II (AT1) receptor is characterized by signal transduction mediated through G protein and phospholipase C. In this study, the micro-localization of mRNAs coding for AT1 receptor and angiotensinogen was carried out(More)
We investigated the effects of epidermal growth factor (EGF) and arginine vasopressin (AVP) on Raf-1-MAP kinase cascade, including Raf-1-kinase (Raf-1-K), MAP kinase kinase (MAPKK), MAP kinase (MAPK) and S6 kinase (S6K) in Madin-Darby canine kidney (MDCK) cells. In a dose-dependent manner (10(-10) M to 10(-6) M), EGF increased autophosphorylation of Raf-1-K(More)
UNLABELLED Vasopressin increases both the urea permeability and osmotic water permeability in the terminal part of the renal inner medullary collecting duct (terminal IMCD). To identify the second messengers that mediate these responses, we measured urea permeability, osmotic water permeability, intracellular calcium concentration, and cyclic AMP(More)
Prostasin is a serine protease present in mammalian urine that increases the activity of the epithelial sodium channel (ENaC) when the two are coexpressed in Xenopus oocytes. To determine if aldosterone, one of the principal regulators of urinary Na reabsorption by the distal nephron, affects prostasin expression, we examined prostasin mRNA and protein in a(More)
Recent studies have revealed that endothelins (ETs) have at least two types of receptors. One receptor has high affinity to ET-1 and ET-2 and low affinity to ET-3 (A type). The other receptor binds almost equally to ET-1, ET-2, and ET-3 (B type). In this study, microlocalization of mRNA coding for the A-type and B-type ET receptors was carried out in the(More)