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Background/Aims: Blood pressure (BP) variability is known as a poor prognostic factor for cardiovascular outcomes. This study assessed the prognostic significance of BP variability in association with increasing age in hemodialysis patients. Methods: We retrospectively analyzed 2,174 patients on hemodialysis from March 2005 to December 2012. The impact of intradialytic and interdialytic BP variability on all-cause mortality according to age groups was analyzed. Results: Kaplan-Meier survival curves for 5-year cumulative mortality showed higher mortality in patients with higher intradialytic systolic and diastolic BP variability as well as interdialytic systolic and diastolic BP variability (log-rank p=0.006, <0.001, 0.018 and < 0.001) in patients aged <55 years, but not in older age groups. Cox proportional analysis revealed that 5-year mortality was associated with intradialytic diastolic BP variability in patients aged <55 years (HR, 2.03 CI, 1.24-3.32). Conclusion: The overall mortality was associated with BP variability in patients aged <55 years, but not in older ages. This result suggests that younger hemodialysis patients with BP variability require further medical attention and intervention to reduce BP variability. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: This study was aimed to examine the prevalence of metabolic syndrome (MS) and chronic kidney disease (CKD), and the association between MS and its components with CKD in Korea. Methods: We excluded diabetes to appreciate the real impact of MS and performed a cross-sectional study using the general health screening data of 10,253,085 (48.86±13.83 years, men 56.18%) participants (age, ≥20 years) from the Korean National Health Screening 2011. CKD was defined as dipstick proteinuria ≥1 or an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2. Results: The prevalence of CKD was 6.15% (men, 5.37%; women, 7.15%). Further, 22.25% study population had MS (abdominal obesity, 27.98%; hypertriglyceridemia, 30.09%; low high-density cholesterol levels, 19.74%; high blood pressure, 43.45%; and high fasting glucose levels, 30.44%). Multivariate-adjusted analysis indicated that proteinuria risk increased in participants with MS (odds ratio [OR] 1.884, 95% confidence interval [CI] 1.867–1.902, P<0.001). The presence of MS was associated with eGFR<60 mL/min/1.73 m2 (OR 1.364, 95% CI 1.355–1.373, P<0.001). MS individual components were also associated with an increased CKD risk. The strength of association between MS and the development of CKD increase as the number of components increased from 1 to 5. In sub-analysis by men and women, MS and its each components were a significant determinant for CKD. Conclusions: MS and its individual components can predict the risk of prevalent CKD for men and women. [ABSTRACT FROM AUTHOR]

Background/Aims: Sildenafil, the first selective phosphodiesterase-5 (PDE5) inhibitor to be widely used for treating erectile dysfunction, has been investigated with regard to its cardioand renoprotective effects in animal models. This study further investigated the renoprotective effects of sildenafil and their molecular mechanisms in deoxycorticosterone acetate (DOCA)-salt hypertensive (DSH) rats. Methods: DOCA strips (200 mg/kg) were implanted in rats 1 week after unilateral nephrectomy. These rats were fed on a control diet, with or without sildenafil (50 mg·kg-1day-1), for 2 weeks. Systolic blood pressure (SBP) was measured by the tail cuff method, and the urinary albumin-to-creatinine ratio (ACR) was calculated. The extent of glomerulosclerosis and tubulointerstitial fibrosis was determined by Masson's trichrome stain. Renal expression of ED-1, transforming growth factor-β1 (TGF-β1), Bax, and Bcl-2 were determined by semiquantitative immunoblotting, polymerase chain reaction (PCR), and immunohistochemistry. TUNEL staining was used for detecting apoptotic cells. Results: The increased SBP in DSH rats was not attenuated by sildenafil treatment. The decreased creatinine clearance and increased ACR in DSH rats, compared with control animals, were attenuated by sildenafil treatment. Further, sildenafil treatment attenuated glomerulosclerosis and tubulointerstitial fibrosis in DSH rats and counteracted the increased expression of ED-1, TGF-β1, and Bax and the decreased expression of Bcl-2 in the kidneys of these rats. The increase in the number of apoptotic cells in DSH rats was attenuated by sildenafil treatment. Conclusion: Sildenafil effectively prevented the progression of renal injury in DSH rats via its anti-inflammatory, antifibrotic, and antiapoptotic effects. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: The present study was aimed to determine whether there is an altered role of local nitric oxide (NO) and atrial natriuretic peptide (ANP) systems in the kidney in association with the angiotensin (Ang) II-induced hypertension. Male Sprague–Dawley rats were used. Ang II (100ng·min−1·kg−1) was infused through entire time course. Thirteenth day after beginning the regimen, kidneys were taken. The protein expression of NO synthase (NOS) and nitrotyrosine was determined by semiquantitative immunoblotting. The mRNA expression of components of ANP system was determined by real-time polymerase chain reaction. The activities of soluble and particulate guanylyl cyclases were determined by the amount of cGMP generated in responses to sodium nitroprusside and ANP, respectively. There developed hypertension and decreased creatinine clearance in the experimental group. The protein expression of eNOS, nNOS and nitrotyrosine was increased in the cortex, while that of iNOS remained unaltered. The urinary excretion of NO increased in Ang II-induced hypertensive rats. The catalytic activity of soluble guanylyl cyclase was blunted in the glomerulus in Ang II-induced hypertensive rats. The mRNA expression of ANP was increased in Ang II-induced hypertensive rats. Neither the expression of NPR-A nor that of NPR-C was changed. The protein expression of neutral endopeptidase was decreased and the activity of particulate guanylyl cyclase was blunted in the glomerulus and papilla in Ang II-induced hypertensive rats. In conclusion, the synthesis of NO and ANP was increased in the kidney of Ang II-induced hypertension, while stimulated cGMP response was blunted. These results suggest desensitization of guanylyl cyclase in the kidney of Ang II-induced hypertensive rats, which may contribute to the associated renal vasoconstriction and hypertension. [Copyright &y& Elsevier]

Abstract: Although deoxycorticosterone acetate (DOCA)–salt hypertension is a volume dependent model of hypertension, it shows polyuria and natriuresis. It is expected that dysregulation of aquaporin water channels (AQPs) and sodium transporters associated with natriuretic peptide (NP) system may play an escape role in sodium retaining state. One week after left unilateral nephrectomy, rats were subcutaneously implanted with silastic DOCA (200 mg/kg) strips. Physiologic saline was supplied as a drinking water to all animals. 4 weeks after operation, the protein expression of AQPs, sodium transporters, and endopeptidase (NEP) was determined in the kidneys by semiquantitative immunoblotting and immunohistochemistry. The mRNA expression of NP system was determined by real-time polymerase chain reaction. The amount of urinary ANP excretion was measured by radioimmunoassay. In DOCA–salt rats, urine osmolality was decreased while urinary excretion of sodium was increased. The expression of AQP1-3 as well as that of α-1 subunit of Na,K–ATPase, NHE3, NKCC2 and NCC was decreased in the kidney. The mRNA expression of ANP, brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP) was increased in the kidney. The expression of NEP was decreased, and urinary ANP excretion was increased. Downregulation of AQPs and sodium transporters may contribute to mineralocorticoid escape in DOCA–salt hypertension. Increased expression of natriuretic peptides associated with downregulation of NEP may play a role in natriuresis. [Copyright &y& Elsevier]

Apparent treatment-resistant hypertension (ATRH) is closely related to chronic kidney disease (CKD); however, the long-term outcomes and the effects of improvement in ATRH in patients with CKD are not well understood. We evaluated the relationship between the persistence of ATRH and the progression of CKD. This cohort study enrolled 1921 patients with CKD. ATRH was defined as blood pressure above 140/90 mmHg and intake of three different types of antihypertensive agents, including diuretics, or intake of four or more different types of antihypertensive agents, regardless of blood pressure. We defined ATRH subgroups according to the ATRH status at the index year and two years later. The prevalence of ATRH at baseline was 14.0%. The presence of ATRH at both time points was an independent risk factor for end-point renal outcome (HR, 1.41; 95% CI, 1.04–1.92; p = 0.027). On the other hand, the presence of ATRH at any one of the time points was not statistically significant. In conclusion, persistent ATRH is more important for the prognosis of renal disease than the initial ATRH status. Continuous follow-up and appropriate treatment are important to improve the renal outcomes. [ABSTRACT FROM AUTHOR]

Abstract: Sympathetic nervous system and atrial natriuretic peptide (ANP) system play fundamental roles in the regulation of cardiovascular functions. Overactivity of sympathetic nervous system can lead into cardiovascular diseases such as heart failure and hypertension. The present study aimed to define which adrenergic receptors (ARs) affect atrial contractility and ANP release and to determine their modification in renal hypertensive rat atria. An α1-AR agonist, cirazoline increased ANP release with positive inotropism. These α1-AR agonist-mediated responses were attenuated by the α1A-AR antagonist, but not by the α1B- or α1D-AR antagonist. An α2-AR agonist, guanabenz and clonidine increased ANP release with negative inotropism and decreased cAMP level. The order of potency for the increased ANP release was cirazoline≫phenylephrine=guanabenz≫clonidine. In contrast, a β-AR agonist, isoproterenol decreased ANP release with positive inotropism and these responses were blocked by the β1-AR antagonist but not by the β2-AR antagonist. The increased cAMP level by isoproterenol was suppressed by pretreatment with both β1- and β2-AR antagonists. In renal hypertensive rat atria, the effects of isoproterenol on atrial contractility, ANP release, and cAMP level were attenuated whereas the effect of cirazoline on ANP release was unaltered. Atrial β1-AR mRNA level but not α1A-AR mRNA level was decreased in renal hypertensive rats. These findings suggest that α1A- and β1-AR oppositely regulate atrial ANP release and that atrial β1-AR expression/function is impaired in renal hypertensive rats. [Copyright &y& Elsevier]

SUMMARY 1. The aim of the present study was to determine whether the regulation of vascular natriuretic peptide receptors (NPR) is related to the local renin–angiotensin system (RAS). 2. Male Sprague-Dawley rats were made two-kidney, one-clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertensive to activate and inhibit the RAS, respectively. Another model of hypertension was induced by treatment with an inhibitor of nitric oxide synthesis, namely N G -nitro-L-arginine methyl ester (L-NAME). 3. The mRNA expression of NPR-A, NPR-C, angiotensin- converting enzyme (ACE) and angiotensin AT1 receptors was determined in the thoracic aorta by semiquantitative reverse transcription–polymerase chain reaction. The particulate guanylyl cyclase activity stimulated by atrial natriuretic peptide (ANP) was also determined in the membrane fraction of the thoracic aorta. 4. The plasma concentrations of ANP were increased significantly in the three models of hypertension. Plasma renin activity was increased in 2K1C hypertension, decreased in DOCA-salt hypertension and not significantly altered in L-NAME hypertension. 5. The mRNA expression of NPR-A and NPR-C was decreased, whereas that of ACE and AT1 receptors was increased in 2K1C and L-NAME hypertension. The mRNA expression of NPR-A and NPR-C was increased, whereas that of ACE and AT1 receptors was decreased in DOCA-salt hypertension. 6. The particulate guanylyl cyclase activity was decreased in 2K1C and L-NAME hypertension and increased in DOCA-salt hypertension. 7. The vascular expression of NPR may be reciprocally regulated by local RAS activity. [ABSTRACT FROM AUTHOR]

The prevalence of metabolic syndrome (MetS) and kidney cancer is increasing, but studies on the effects of MetS and its components on kidney cancer development have had ambiguous results. Overall, 7,613,865 patients from the Korean National Health Insurance System were analyzed and followed up until 2017. Patients with ≥3 of the necessary five components of MetS were diagnosed with MetS. Patients were divided into subgroups according to two consecutive physical examinations conducted every two years. The Cox proportional hazard regression model was used to survey the independent association between MetS and the risk of kidney cancer development. Kidney cancer risk was significantly higher in patients with MetS, and there was no difference according to sex. The hazards ratio of kidney cancer increased with increasing number of MetS components. For patients not diagnosed with MetS but with abdominal obesity and hypertension, the likelihood of developing kidney cancer was similar to that of patients diagnosed with MetS. Patients with improved MetS within two years had increased risk of kidney cancer compared with those without MetS. MetS is an independent risk factor for kidney cancer, and the obesity and hypertension components of MetS are also powerful risk factors. [ABSTRACT FROM AUTHOR]

The novel histone deacetylase inhibitor CG200745 was initially developed to treat various hematological and solid cancers. We investigated the molecular mechanisms associated with the renoprotective effects of CG200745 using deoxycorticosterone acetate (DOCA)-salt hypertensive (DSH) rats. DOCA strips (200 mg/kg) were implanted into rats one week after unilateral nephrectomy. Two weeks after DOCA implantation, DSH rats were randomly divided into two groups that received either physiological saline or CG200745 (5 mg/kg/day) for another two weeks. The extent of glomerulosclerosis and tubulointerstitial fibrosis was determined by Masson's trichrome staining. The renal expression of fibrosis and inflammatory markers was detected by semiquantitative immunoblotting, a polymerase chain reaction, and immunohistochemistry. Pathological signs such as glomerulosclerosis, tubulointerstitial fibrosis, increased systolic blood pressure, decreased creatinine clearance, and increased albumin-to-creatinine ratios in DSH rats were alleviated by CG200745 treatment compared to those manifestations in positive control animals. Furthermore, this treatment counteracted the increased expression of αSMA, TGF-β1, and Bax, and the decreased expression of Bcl-2 in the kidneys of DSH rats. It also attenuated the increase in the number of apoptotic cells in DSH rats. Thus, CG200745 can effectively prevent the progression of renal injury in DSH rats by exerting anti-inflammatory, anti-fibrotic, and anti-apoptotic effects. [ABSTRACT FROM AUTHOR]