Resveratrol treatment was beneficial in preventing the development of concentric hypertrophy and cardiac dysfunction in SHR. The cardioprotective effect of resveratrol in SHR may be partially mediated by a reduction in oxidative stress. Thus, resveratrol may have potential in preventing cardiac impairment in patients with essential hypertension.

Background:In some jurisdictions, routine reporting of the estimated glomerular filtration rate (eGFR) has led to an increase in nephrology referrals and wait times.Objective:We describe the use of the Kidney Failure Risk Equation (KFRE) as part of a triage process for new nephrology referrals for patients with chronic kidney disease stages 3 to 5 in a Canadian province.Design:A quasi-experimental study design was used.Setting:This study took place in Manitoba, Canada.Measurements:Demographics, laboratory values, referral numbers, and wait times were compared between periods.Methods:In 2012, we adopted a risk-based cutoff of 3% over 5 years using the KFRE as a threshold for triage of new referrals. Referrals who did not meet other prespecified criteria (such as pregnancy, suspected glomerulonephritis, etc) and had a kidney failure risk of <3% over 5 years were returned to primary care with recommendations based on diabetes and hypertension guidelines. The average wait time and number of consults seen between the pretriage (January 1, 2011, to December 31, 2011) and posttriage period (January 1, 2013, to December 31, 2013) were compared using a general linear model.Results:In the pretriage period, the median number of referrals was 68/month (range: 44-76); this increased to 94/month (range: 61-147) in the posttriage period. In the posttriage period, 35% of referrals were booked as urgent, 31% as nonurgent, and 34% of referrals were not booked. The median wait times improved from 230 days (range: 126-355) in the pretriage period to 58 days (range: 48-69) in the posttriage period.Limitations:We do not have long-term follow-up on patients triaged as low risk. Our study may not be applicable to nephrology teams operating under capacity without wait lists. We did not collect detailed information on all referrals in the pretriage period, so any differences in our pretriage and posttriage patient groups may be unaccounted for.Conclusions:Our risk-based triage scheme is an effective health policy tool that led to improved wait times and access to care for patients at highest risk of progression to kidney failure.

This study was designed to examine the effects of the antioxidant resveratrol on cardiac structure and function in pressure overload (PO)-induced cardiac hypertrophy. Male Sprague-Dawley rats were subjected to sham operation and the aortic banding procedure. A subgroup of sham control and aortic-banded rats were treated with resveratrol for 2 wk after surgery. Echocardiographic analysis of cardiac structure and function along with Western blot analysis of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and redox factor-1 (ref-1) were performed in all groups after 4 wk of surgery. Banded rats showed significantly increased left ventricle-to-body weight ratio. Echocardiographic analysis showed that the interventricular septal wall thickness and left ventricular posterior wall thickness at systole and diastole were significantly increased in banded rats. Also, a significant increase in isovolumic relaxation time was observed in banded rats. Measured eNOS, iNOS, and ref-1 protein levels were significantly reduced in banded rats. Resveratrol treatment prevented the above changes in cardiac structure, function, and protein expression in banded rats. Aortic banding after 4 wk resulted in concentric remodeling and impaired contractile function due to PO on the heart. The 2-wk treatment with resveratrol was found to abolish PO-induced cardiac hypertrophy. Resveratrol may therefore be beneficial against PO-induced cardiac hypertrophy found in clinical settings of hypertension and aortic valve stenosis.

Cardiac hypertrophy is a compensatory enlargement of the heart due to either volume overload (VO) and/or pressure overload (PO) that develops into heart failure if left untreated. The polyphenol resveratrol has been reported to regress PO-induced cardiac hypertrophy in rats. Our aim in this study was to assess the effectiveness of resveratrol on VO-induced cardiac hypertrophy. Sprague Dawley rats were subjected to aortocaval shunt and abdominal aortic banding surgeries to create VO and PO, respectively; sham-operated rats served as controls. To arrest the development of cardiac hypertrophy, daily resveratrol treatment (2.5 mg/kg body weight) was started 2 d postsurgery for 26 d and assessed by echocardiography at 2, 14, and 28 d postsurgery. Similarly, to regress cardiac hypertrophy resveratrol treatment was started after structural and functional abnormalities developed (14 d postsurgery) for 14 d and assessed by echocardiography at 14 and 28 d postsurgery. VO surgeries induced eccentric hypertrophy characterized by increased left ventricle internal dimensions (LVID) without wall thickening. Conversely, PO induced concentric hypertrophy with increased wall thickness without change in LVID. Lipid peroxidation, a marker for oxidative stress, was significantly elevated in both PO and VO rats. Resveratrol treatment arrested the development and regressed abnormalities in cardiac structure and function in PO but not VO rats. Treatment with resveratrol also significantly reduced oxidative stress in cardiac tissue of PO and VO rats. The results on cardiac structure and function demonstrate a potential for resveratrol in the treatment of cardiac hypertrophy due to PO but not VO.

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The ability of resveratrol to limit the increase in compliance of SHR arteries is likely related to inhibitory effects on remodeling and pro-growth ERK signaling rather than blood pressure or arterial wall component stiffness.

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Many commonly used medications can cause long QT syndrome and thus increase the risk of life-threatening arrhythmias. High-affinity human Ether-à -go-go-related gene (HERG) potassium channel blockade by structurally diverse compounds is almost exclusively responsible for this side effect. Understanding drug-HERG channel interactions is an important step in avoiding drug-induced long QT syndromes. Previous studies have found that disrupting HERG inactivation reduces the degree of drug block and have suggested that the inactivated state is the preferential state for drug binding to HERG channels. However, recent studies have also shown that inactivation does not dictate drug sensitivity of HERG channels. In the present study, we examined the effect of inactivation gating on cisapride block of HERG. Modulation of HERG inactivation was achieved by either changing extracellular K ϩ or Cs ϩ concentrations or by mutations of the channel. We found that although inactivation facilitated cisapride block of the HERG K ϩ current, it was not coupled with cisapride block of HERG when the Cs ϩ current was recorded. Furthermore, cisapride block of the HERG K ϩ current was not linked with inactivation in the mutant HERG channels F656V and F656M. Our results suggest that inactivation facilitates cisapride block of HERG channels through affecting the positioning of Phe-656.