Publications by authors named "Yoshikazu Muroya"

Objective: Exercise training has antihypertensive and renoprotective effects in humans and rats. However, the effects of exercise training on renal disorders that occur with salt-sensitive hypertension remains unclear. The study aim was to investigate the effects and mechanisms of exercise training on renal function in a rat model of salt-sensitive hypertension.

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Background: The genes and mechanisms involved in the association between diabetes or hypertension and CKD risk are unclear. Previous studies have implicated a role for -adducin (ADD3), a cytoskeletal protein encoded by .

Methods: We investigated renal vascular function and and the susceptibility to CKD in rats with wild-type or mutated and in genetically modified rats with overexpression or knockout of ADD3.

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Exit-site infection poses a risk for peritonitis and can shorten peritoneal dialysis (PD) vintage. A loose fit of the skin around the catheter at the exit site can push bacteria surrounding the catheter into the subcutaneous tunnel. Negative-pressure wound therapy (NPWT) has been used to hasten healing of the wound after an operation or to treat pressure ulcers.

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Article Synopsis
  • Tolvaptan is an effective treatment for polycystic kidney disease (PKD) but causes increased urine production (polyuria), leading researchers to investigate whether hydrochlorothiazide (HCTZ) could help reduce this side effect.
  • In a study with male PCK rats, the combination of tolvaptan and HCTZ significantly lowered urine output compared to tolvaptan alone, while still maintaining the beneficial effects on kidney cyst size and protein expression.
  • The results suggest that pairing HCTZ with tolvaptan can effectively manage polyuria without diminishing the positive outcomes of tolvaptan, potentially enhancing treatment strategies for patients with PKD.
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Angiotensin II (AngII) stimulates the renal production and release of 20-hydroxyeicosatetraenoic acids (20-HETE), which is a major metabolite of arachidonic acid catalyzed by CYP4A isoforms. However, the effects of AngII on CYP4A isoform expression in the kidney and its mechanism remains unclear. To clarify the regulation of CYP4A isoform expression by AngII, we examined the chronic effects of AngII and AngII type 1 receptor (AT1-R) blockade on CYP4A isoform expression.

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The incidence and severity of acute kidney injury is increased in patients with diabetes and with aging. However, the mechanisms involved have not been clearly established. The present study examined the effects of aging and diabetes on the severity of renal ischemia-reperfusion (IR) injury in Sprague-Dawley (SD) and type 2 diabetic (T2DN) rats.

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TGF-β1, which can cause renal tubular injury through a vacuolar-type H-ATPase (V-ATPase)-mediated pathway, is induced by the glucose degradation product methylglyoxal to yield peritoneal injury and fibrosis. The present study investigated the roles of V-ATPase and its accessory protein, the (pro)renin receptor, in peritoneal fibrosis during peritoneal dialysis. Rats daily administered 20 mM methylglyoxal intraperitoneally developed significant peritoneal fibrosis after 7 days with increased expression of TGF-β and V-ATPase, which was reduced by the inhibition of V-ATPase with co-administration of 100 mM bafilomycin A1.

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Interventional radiology procedures often involve lengthy exposure to fluoroscopy-derived radiation. We therefore devised a videofluoroscopic swallowing study (VFSS) procedure using a human phantom that proved to protect the patient and physician by reducing the radiation dose. We evaluated a new lead-shielding device and separately attached additional filters (1.

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Cytochrome P450s enzymes catalyze the metabolism of arachidonic acid to epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acid and hydroxyeicosatetraeonic acid (HETEs). 20-HETE is a vasoconstrictor that depolarizes vascular smooth muscle cells by blocking K+ channels. EETs serve as endothelial derived hyperpolarizing factors.

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Background: Proteinuria plays an essential role in the progression of tubulointerstitial damage, which causes end-stage renal disease. An increased load of fatty acids bound to albumin reabsorbed into proximal tubular epithelial cells (PTECs) contributes to tubulointerstitial damage. Fibrates, agonists of peroxisome proliferator-activated receptor α (PPARα), have renoprotective effects against proteinuria whereas the effects of these compounds on fatty acid metabolism in the kidney are still unknown.

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Exercise training is known to exert multiple beneficial effects including renal protection in type 2 diabetes mellitus and obesity. However, the mechanisms regulating these actions remain unclear. The present study evaluated the effects of chronic running exercise on the early stage of diabetic nephropathy, focusing on nitric oxide synthase (NOS), oxidative stress and glycation in the kidneys of Zucker diabetic fatty (ZDF) rats.

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Ischemia-reperfusion (IR) injury is the most common cause of AKI. The susceptibility to develop AKI varies widely among patients. However, little is known about the genes involved.

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A functional receptor for renin and prorenin ((P)RR) was identified as a new component of the renin-angiotensin system. The precise localization of (P)RR in the kidney has not been clarified. The present study was designed to determine the localization of (P)RR in the rat nephron and to investigate the regulation of renal (P)RR expression by high salt (HS) intake.

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Purpose Of Review: Cytochrome (CYP) P450 metabolites of arachidonic acid, 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) contribute to the regulation of renal tubular and vascular function. This review highlights the results of the recent genetic studies in humans and rodent models, indicating that these eicosanoids participate in the control of blood pressure (BP), chronic kidney disease (CKD), renal ischemia-reperfusion injury (IRI) and polycystic kidney disease (PKD).

Recent Findings: Endogenous 20-HETE has been reported to play an essential role in the myogenic and tubuloglomerular feedback responses in the afferent arteriole, and a deficiency of 20-HETE contributes to the development of hypertension and renal injury in Dahl S rats.

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There is an interaction between heart and kidney diseases, which is a condition termed cardiorenal syndrome. Exercise training has cardioprotective effects, involving upregulation of endothelial (e) nitric oxide synthase (NOS) in the cardiovascular system. However, the effects of exercise training on NOS in the kidney with heart disease are unknown.

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Exercise training is known to have antihypertensive effects in humans and animals with hypertension, as well as to exhibit renal protective effects in animal models of hypertension and chronic renal failure. However, the mechanisms regulating these effects of exercise training remain unclear. The present study examined the effects of exercise training on nitric oxide synthase (NOS) in the kidneys of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats.

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Proteinuria is considered to play an essential role in the progression of tubulointerstitial damage, which causes end-stage renal disease. Fatty acid-binding albumins are filtered through glomeruli and reabsorbed into proximal tubular epithelial cells (PTECs). However, the role of fatty acid metabolism associated with albuminuria in the development of tubulointerstitial damage remains unclear.

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Background And Method: Both nitric oxide synthase (NOS) expression and oxidative stress are elevated in the tissues of spontaneously hypertensive rats (SHR) compared with Wistar-Kyoto rats (WKY). The purpose of the present study was to determine the relationship between the endothelial and neuronal NOS (eNOS and nNOS) expression and oxidative stress in the kidney of SHR and WKY.

Results: Plasma and urinary hydrogen peroxide (H₂O₂) and nitrate/nitrite (NOx), the renal NADPH oxidase activity and eNOS and nNOS expressions were all higher in SHR than in WKY.

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Objective: 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, statins reduce blood pressure and have beneficial effects in cardiovascular and kidney diseases. The present study examined the effect of chronic treatment with atorvastatin (ATV) on the expression of nitric oxide synthase (NOS) and the activity of Rho-kinase and Akt in the kidney of spontaneously hypertensive rats (SHRs).

Methods: SHRs were treated with ATV for 8 weeks and the SBP was measured.

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