Daisuke Morisawa

Comparison of the Effects of Telmisartan and Olmesartan on Home Blood Pressure, Glucose, and Lipid Profiles in Patients with Hypertension, Chronic Heart Failure, and Metabolic Syndrome

We compared the effects of telmisartan and olmesartan in 20 patients with chronic heart failure and metabolic syndrome. The subjects underwent once-daily 40 mg telmisartan for at least 3 months before switching to once-daily 20 mg olmesartan for the next 3 months (post 1). They were then treated with 3 months of once-daily 40 mg telmisartan (post 2). Systolic and diastolic blood pressure in the early morning, plasma B-type natriuretic peptide, serum total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels were increased at post 1 (p<0.005, p<0.05, p<0.05, p<0.05, p<0.05, and p<0.005 vs. baseline, respectively) before returning to their baseline values at post 2. The changes in plasma B-type natriuretic peptide levels correlated significantly with the shifts in systolic and diastolic blood pressure in the early morning at posts 1 and 2. Meanwhile, there were no fluctuations in either blood pressure in the late evening or in the outpatient room; nor were there fluctuations in heart rate. Simultaneously, neither serum high-density lipoprotein cholesterol nor fasting blood sugar levels differed significantly between posts. Moreover, telmisartan had more beneficial effects on glucose and lipid profiles in patients with relatively high HbA1c, serum total and low-density lipoprotein cholesterol, and triglyceride levels. Therefore, we concluded that telmisartan was more beneficial than olmesartan for controlling blood pressure in the early morning, as well as for improving glucose and lipid profiles in patients with hypertension, chronic heart failure, and metabolic syndrome.

Increased renal iron accumulation in hypertensive nephropathy of salt-loaded hypertensive rats.

Although iron is reported to be associated with the pathogenesis of chronic kidney disease, it is unknown whether iron participates in the pathophysiology of nephrosclerosis. Here, we investigate whether iron is involved in the development of hypertensive nephropathy and the effects of iron restriction on nephrosclerosis in salt- loaded stroke-prone spontaneously hypertensive rats (SHRSP). SHRSP were given either a normal or high-salt diet for 8 weeks. Another subset of SHRSP were fed a high-salt with iron-restricted diet. SHRSP given a high-salt diet developed severe hypertension and nephrosclerosis. As a result, survival rate was decreased after 8 weeks diet. Importantly, massive iron accumulation and increased iron content were observed in the kidneys of salt-loaded SHRSP, along with increased superoxide production, urinary 8-Hydroxy-2′-deoxyguanosine excretion, and urinary iron excretion; however, these changes were markedly attenuated by iron restriction. Of interest, expression of cellular iron transport proteins, transferrin receptor 1 and divalent metal transporter 1, was increased in the tubules of salt-loaded SHRSP. Notably, iron restriction attenuated the development of severe hypertension and nephrosclerosis, thereby improving survival rate in salt-loaded SHRSP. Taken together, these results suggest a novel mechanism by which iron plays a role in the development of hypertensive nephropathy and establish the effects of iron restriction on salt-induced nephrosclerosis.

Intravenous Salt Supplementation With Low-Dose Furosemide for Treatment of Acute Decompensated Heart Failure

BACKGROUND Theoretically, salt supplementation should promote diuresis through increasing the glomerular filtration rate (GFR) during treatment of acute decompensated heart failure (ADHF) even with low-dose furosemide; however, there is little evidence to support this idea. METHODS AND RESULTS This was a prospective, randomized, open-label, controlled trial that compared the diuretic effectiveness of salt infusion with that of glucose infusion supplemented with low-dose furosemide in 44 consecutive patients with ADHF. Patients were randomly administered 1.7% hypertonic saline solution supplemented with 40 mg furosemide (salt infusion group) or glucose supplemented with 40 mg furosemide (glucose infusion group). Our major end points were 24-hour urinary volume and GFR. Urinary volume was greater in the salt infusion group than in the glucose infusion group (2,701 ± 920 vs 1,777 ± 797 mL; P < .001). There was no significant difference in the estimated GFR at baseline. Creatinine clearance for 24 h was greater in the salt infusion group than in the glucose infusion group (63.5 ± 52.6 vs 39.0 ± 26.3 mL min(-1) 1.73 m(-2); P = .048). CONCLUSIONS Salt supplementation rather than salt restriction evoked favorable diuresis through increasing GFR. The findings support an efficacious novel approach of the treatment of ADHF.

Association between renal iron accumulation and renal interstitial fibrosis in a rat model of chronic kidney disease

Iron accumulation is associated with the pathophysiology of chronic kidney disease (CKD). Renal fibrosis is a final common feature that contributes to the progression of CKD; however, little is known about the association between renal iron accumulation and renal interstitial fibrosis in CKD. Here we investigate the effects of iron chelation on renal interstitial fibrosis in a rat model of CKD. CKD was induced by 5/6 nephrectomy in Sprague–Dawley rats. At 8 weeks after operation, 5/6 nephrectomized rats were administered an oral iron chelator, deferasirox (DFX), in chow for 8 weeks. Other CKD rats were given a normal diet. Sham-operative rats given a normal diet served as a control. CKD rats exhibited hypertension, glomerulosclerosis and renal interstitial fibrosis. Iron chelation with DFX did not change hypertension and glomerulosclerosis; however, renal interstitial fibrosis was attenuated in CKD rats. Consistent with these findings, renal gene expression of collagen type III and transforming growth factor-β was increased in CKD rats compared with the controls, while iron chelation suppressed these increments. In addition, a decrease in vimentin along an increase in E-cadherin in renal gene expression was observed in CKD rats with iron chelation. CKD rats also showed increased CD68-positive cells in the kidney, whereas its increase was attenuated by iron deprivation. Similarly, increased renal gene expression of CD68, tumor necrosis factor-α and monocyte chemoattractant protein-1 was suppressed in CKD rats with iron chelation. Renal iron accumulation seems to be associated with renal interstitial fibrosis in a rat model of CKD.

Iron restriction inhibits renal injury in aldosterone/salt-induced hypertensive mice

Excess iron is associated with the pathogenesis of several renal diseases. Aldosterone is reported to have deleterious effects on the kidney, but there have been no reports of the role of iron in aldosterone/salt-induced renal injury. Therefore, we investigated the effects of dietary iron restriction on the development of hypertension and renal injury in aldosterone/salt-induced hypertensive mice. Ten-week-old male C57BL/6J mice were uninephrectomized and infused with aldosterone for four weeks. These were divided into two groups: one fed a high-salt diet (Aldo) and the other fed a high-salt with iron-restricted diet (Aldo-IR). Vehicle-infused mice without a uninephrectomy were also divided into two groups: one fed a normal diet (control) and the other fed an iron-restricted diet (IR) for 4 weeks. As compared with control and IR mice, Aldo mice showed an increase in both systolic blood pressure and urinary albumin/creatinine ratio, but these increases were reduced in the Aldo-IR group. In addition, renal histology revealed that Aldo mice exhibited glomerulosclerosis and tubulointerstitial fibrosis, whereas these changes were attenuated in Aldo-IR mice. Expression of intracellular iron transport protein transferrin receptor 1 was increased in the renal tubules of Aldo mice compared with control mice. Dietary iron restriction attenuated the development of hypertension and renal injury in aldosterone/salt-induced hypertensive mice.

Treatment of collateral channel perforation during percutaneous coronary intervention for chronic total occlusion with retrograde approach

We describe one case of septal and two cases of epicardial collateral channel perforation during percutaneous coronary intervention by the retrograde approach for chronic total occlusion. After coil embolization of the channel perforation area, additional treatments were required in all three cases to stop bleeding. All three cases required injection of autologous clots, with one case also requiring subsequent injection of fibrin glue.

Predictive factors for successful weaning from percutaneous cardiopulmonary support in patients with cardiogenic shock complicating acute myocardial infarction

BACKGROUND AND PURPOSE Percutaneous cardiopulmonary support (PCPS) is useful in the rescue of patients who have experienced severe cardiogenic shock. We investigated the predictive factors of survival among patients with cardiogenic shock requiring PCPS. METHODS AND SUBJECTS We enrolled 29 patients (21 men and 8 women, 73 ± 10 years old) with circulatory collapse complicating acute myocardial infarction (AMI) requiring PCPS. Fifteen patients could be weaned from PCPS and survived for more than 1 month (group A), while the other 14 patients could not (group B). We investigated the initial PCPS settings, and performed the appropriate laboratory tests. Hemodynamic data and arterial base excess (BE) values were recorded throughout the PCPS treatment. RESULTS There was no difference in the laboratory test results or the left ventricular ejection fraction between the groups at the start of PCPS. PCPS flow (l/min) was significantly lower in group A than in group B at the 24th hour of PCPS (2.26 ± 0.36 and 2.54 ± 0.41, respectively). There were no differences in blood pressure between the groups. During the 24-h period prior to the end of PCPS, BE remained almost normal in group A. In group B, BE decreased continuously throughout the same period. BE values were significantly lower compared to those obtained in group A 12h prior to the end of PCPS. CONCLUSIONS A reduction in PCPS flow without hemodynamic collapse may allow for successful weaning from PCPS. BE may be a potent factor in determining when to terminate PCPS.

Transferrin Receptor 1 in Chronic Hypoxia-Induced Pulmonary Vascular Remodeling

BACKGROUND Iron is associated with the pathophysiology of several cardiovascular diseases, including pulmonary hypertension (PH). In addition, disrupted pulmonary iron homeostasis has been reported in several chronic lung diseases. Transferrin receptor 1 (TfR1) plays a key role in cellular iron transport. However, the role of TfR1 in the pathophysiology of PH has not been well characterized. In this study, we investigate the role of TfR1 in the development of hypoxia-induced pulmonary vascular remodeling. METHODS PH was induced by exposing wild-type (WT) mice and TfR1 hetero knockout mice to hypoxia for 4 weeks and evaluated via assessment of pulmonary vascular remodeling, right ventricular (RV) systolic pressure, and RV hypertrophy. In addition, we assessed the functional role of TfR1 in pulmonary artery smooth muscle cells in vitro. RESULTS The morphology of pulmonary arteries did not differ between WT mice and TfR1 hetero knockout mice under normoxic conditions. In contrast, TfR1 hetero knockout mice exposed to 4 weeks hypoxia showed attenuated pulmonary vascular remodeling, RV systolic pressure, and RV hypertrophy compared with WT mice. In addition, the depletion of TfR1 by RNA interference attenuated human pulmonary artery smooth muscle cells proliferation induced by platelet-derived growth factor-BB (PDGF-BB) in vitro. CONCLUSIONS These results suggest that TfR1 plays an important role in the development of hypoxia-induced pulmonary vascular remodeling.

Interleukin-18 disruption suppresses hypoxia-induced pulmonary artery hypertension in mice

Article history: Received 31 July 2015 Received in revised form 24 September 2015 Accepted 28 September 2015 Available online 03 October 2015 atria, RV free wall was removed from left ventricle (LV). Each ventricle was weighed and the ratio of RV weight to LV plus septum weight (RV/LV + Sp) was calculated. Lungs were fixed with 4% buffered paraformaldehyde for 24 h, embedded in paraffin, and cut into 4-μm-thick sections. Hematoxylineosin (HE) and Elastica van Gieson (EVG) stainings were performed using standard protocols. Immunofluorescence staining was performed using a primary anti-α-smooth muscle actin (α-SMA) mouse antibody

Temporary dietary iron restriction affects the process of thrombus resolution in a rat model of deep vein thrombosis.

Background Deep vein thrombosis (DVT) is a major cause of pulmonary thromboembolism and sudden death. Thus, it is important to consider the pathophysiology of DVT. Recently, iron has been reported to be associated with thrombotic diseases. Hence, in this study, we investigate the effects of dietary iron restriction on the process of thrombus resolution in a rat model of DVT. Methods We induced DVT in 8-week-old male Sprague-Dawley rats by performing ligations of their inferior venae cavae. The rats were then given either a normal diet (DVT group) or an iron-restricted diet (DVT+IR group). Thrombosed inferior venae cavae were harvested at 5 days after ligation. Results The iron-restricted diet reduced venous thrombus size compared to the normal diet. Intrathrombotic collagen content was diminished in the DVT+IR group compared to the DVT group. In addition, intrathrombotic gene expression and the activity of matrix metalloproteinase-9 were increased in the DVT+IR group compared to the DVT group. Furthermore, the DVT+IR group had greater intrathrombotic neovascularization as well as higher gene expression levels of urokinase-type plasminogen activator and tissue-type plasminogen activator than the DVT group. The iron-restricted diet decreased intrathrombotic superoxide production compared to the normal diet. Conclusions These results suggest that dietary iron restriction affects the process of thrombus resolution in DVT.