Risk Factors and Prevalence of Deep Vein Thrombosis After the 2016 Kumamoto Earthquakes.

BACKGROUND: After previous earthquakes, a high prevalence of deep vein thrombosis (DVT) has been reported. We examined DVT prevalence and risk factors in evacuees of the Kumamoto earthquakes by performing mobile DVT screening at various evacuation centers around the epicenter. Methods and Results: For 1 month after the Kumamoto earthquake on 14 April 2016, mobile DVT screening using portable ultrasonography (US) was performed at 80 evacuation centers. Questionnaires, physical examination, and US of the lower limb were carried out, and simple D-dimer measurements were undertaken for DVT-positive examinees. The total number of examinees was 1,673, of whom 178 (10.6%) had DVT. The prevalence of DVT seemed to be gradually decreasing in the screening period, but age, use of sleep medication, prevalence of hypertension, dyslipidemia, leg edema, and lower leg varix were significantly higher in the DVT positive group than in the negative group. On multivariable logistic regression analysis, high age (≥70 years old), use of sleep medication, lower leg edema, and lower leg varix were significant predictors of DVT. In examinees with these 4 predictors, the DVT positive rate was 71.4%. CONCLUSIONS: In the first month after the Kumamoto earthquakes, DVT prevalence and severity, evaluated on D-dimer level, decreased with the passage of time. Mobile DVT screening indicated significant factors stratifying DVT risk in the evacuees.

The First Silicon(IV) Corrole Complexes: Synthesis, Structures, Properties, and Formation of a µ-Oxo Dimer.

The first SiIV corrole complexes were synthesized in good yields by treatment of meso-triarylcorroles with tetrachlorosilane in 1,2-dichloroethane at 60 °C. The central silicon atom possesses a square-pyramidal coordination geometry with slightly longer Si-N bond lengths as compared with those of known triazacorrole SiIV complexes. The SiIV corrole complexes exhibit sharp and blue-shifted absorption spectra and larger fluorescence quantum yields as compared with the corresponding free-base corroles. A µ-oxo dimer of a SiIV corrole was synthesized upon treatment with methanesulfonyl chloride in pyridine at 100 °C. This dimer shows a face-to-face structure with a 90° twist in the solid state. Although the dimer exhibits a blue-shifted Soret band, reflecting the face-to-face geometry, it displays a largely red-shifted and broad fluorescence spectrum with a large Stokes shift, suggesting a large structural change in the S1 state. These intriguing optical properties have been comprehensively studied by magnetic circular dichroism (MCD) spectroscopy, femtosecond transient absorption (fs-TA) measurements, and theoretical calculations.

Rational Synthesis of Antiaromatic 5,15-Dioxaporphyrin and Oxidation into ß,ß-Linked Dimers.

5,15-Dioxaporphyrin was synthesized for the first time by a nucleophilic aromatic substitution reaction of a nickel bis(α,α'-dibromodipyrrin) complex with benzaldoxime, followed by an intramolecular annulation of the α-hydroxy-substituted intermediate. This unprecedented molecule is a 20π-electron antiaromatic system, in terms of Hückel's rule of aromaticity, because lone pair electrons of oxygen atoms are incorporated into the 18π-electron conjugated system of the porphyrin. A theoretical analysis based on the gauge-including magnetically induced current method confirmed its antiaromaticity and a dominant inner ring pathway for the ring current. The unique reactivity of 5,15-dioxaporphyrin forming a ß,ß-linked dimer upon oxidation was also revealed.

Do predators prefer toxic animals? A case of chemical discrimination by an Asian snake that sequesters firefly toxins.

Several Asian natricine snakes of the genus Rhabdophis feed on toads and sequester steroidal cardiac toxins known as bufadienolides (BDs) from them. A recent study revealed that species of the Rhabdophis nuchalis Group ingest lampyrine fireflies to sequester BDs. Although several species of fireflies are distributed in the habitat of the R. nuchalis Group, only lampyrine fireflies, which have BDs, are included in the diet of these snakes. Thus, we hypothesized that the R. nuchalis Group chemically distinguishes fireflies that have BDs from those that do not have BDs. We also predicted that the R. nuchalis Group detects BDs as the chemical cue of toxin source. To test these predictions, we conducted 3 behavioral experiments using Rhabdophis chiwen, which belongs to the R. nuchalis Group. In the first experiment, R. chiwen showed a moderate tongue flicking response to cinobufagin, a compound of BDs. On the other hand, the snake showed a higher response to the chemical stimuli of lampyrine fireflies (BD fireflies) than those of lucioline fireflies (non-BD fireflies). In the second experiment, in which we provided live BD and non-BD fireflies, the snake voluntarily consumed only the former. In the third, a Y-maze experiment, the snake tended to select the chemical trail of BD fireflies more frequently than that of non-BD fireflies. These results demonstrated that R. chiwen discriminates BD fireflies from non-BD fireflies, but the prediction that BDs are involved in this discrimination was not fully supported. To identify the proximate mechanisms of the recognition of novel toxic prey in the R. nuchalis Group, further investigation is necessary.

Telmisartan protects against diabetic vascular complications in a mouse model of obesity and type 2 diabetes, partially through peroxisome proliferator activated receptor-γ-dependent activity.

Experimental and clinical data support the notion that peroxisome proliferator-activated receptor γ (PPARγ) activation is associated with anti-atherosclerosis as well as anti-diabetic effect. Telmisartan, an angiotensin receptor blocker (ARB), acts as a partial PPARγ agonist. We hypothesized that telmisartan protects against diabetic vascular complications, through PPARγ activation. We compared the effects of telmisartan, telmisartan combined with GW9662 (a PPARγ antagonist), and losartan with no PPARγ activity on vascular injury in obese type 2 diabetic db/db mice. Compared to losartan, telmisartan significantly ameliorated vascular endothelial dysfunction, downregulation of phospho-eNOS, and coronary arterial remodeling in db/db mice. More vascular protective effects of telmisartan than losartan were associated with greater anti-inflammatory effects of telmisartan, as shown by attenuation of vascular nuclear factor kappa B (NFκB) activation and tumor necrosis factor α. Coadministration of GW9662 with telmisartan abolished the above mentioned greater protective effects of telmisartan against vascular injury than losartan in db/db mice. Thus, PPARγ activity appears to be involved in the vascular protective effects of telmisartan in db/db mice. Moreover, telmisartan, but not losartan, prevented the downregulation of vascular PPARγ in db/db mice and this effect of telmisartan was cancelled by the coadministration of GW9662. Our data provided the first evidence indicating that PPARγ activity of telmisartan contributed to the protective effects of telmisartan against diabetic vascular complication. PPARγ activity of telmisartan was involved in the normalization of vascular PPARγ downregulation in diabetic mice. Thus, telmisartan seems to exert vascular protective effects in hypertensive patients with diabetes.

Nifedipine prevents vascular endothelial dysfunction in a mouse model of obesity and type 2 diabetes, by improving eNOS dysfunction and dephosphorylation.

The effect of calcium channel blockers (CCBs) on type 2 diabetes is still unclear. The present study was undertaken to examine the efficacy of nifedipine, a dihydropyridine CCB, on obesity, glucose intolerance and vascular endothelial dysfunction in db/db mice (a mouse model of obesity and type 2 diabetes). db/db mice, fed high-fat diet (HFD) were treated with vehicle, nifedipine (10 mg kg(-1) day(-1)) or hydralazine (5 mg kg(-1) day(-1)) for 4 weeks, and the protective effects were compared. Although nifedipine and hydralazine exerted similar blood pressure lowering in db/db mice, neither affected body weight, fat weight, and glucose intolerance of db/db mice. However, nifedipine, but not hydralazine, significantly improved vascular endothelial function in db/db mice, being accompanied by more attenuation of vascular superoxide by nifedipine than hydralazine. These protective effects of nifedipine were attributed to the attenuation of eNOS uncoupling as shown by the prevention of vascular endothelial nitric oxide synthase (eNOS) dimer disruption, and the prevention of dihydrofolate reductase (DHFR) downregulation, the key enzyme responsible for eNOS uncoupling. Moreover, nifedipine, but not hydralazine, significantly prevented the decreases in phosphorylation of vascular akt and eNOS in db/db mice. Our work provided the first evidence that nifedipine prevents vascular endothelial dysfunction, through the inhibition of eNOS uncoupling and the enhancement of eNOS phosphorylation, independently of blood pressure-lowering effect. We propose that nifedipine may be a promising therapeutic agent for cardiovascular complications in type 2 diabetes.

Ezetimibe ameliorates cardiovascular complications and hepatic steatosis in obese and type 2 diabetic db/db mice.

Type 2 diabetes plays a major role in the development of cardiovascular diseases. The present study was undertaken to investigate the effect of ezetimibe, a potent cholesterol absorption inhibitor, on cardiovascular injury of obese and type 2 diabetic db/db mice. Diabetic db/db mice fed a Western diet were given ezetimibe for 9 weeks, and the effects on cardiovascular injury and hepatic steatosis were examined. Ezetimibe treatment of db/db mice significantly improved vascular endothelial function, which was associated with the restoration of the decreased phospho-Akt and phospho-endothelial nitric-oxide synthase (eNOS). Moreover, ezetimibe also reduced vascular superoxide levels in db/db mice, accompanied by the attenuation of NADPH oxidase subunit gp91(phox) and Nox4 and the prevention of down-regulation of Cu/Zn-superoxide dismutase (SOD) and extracellular SOD. Thus, the improvement of vascular endothelial function by ezetimibe in diabetic mice seems to be attributed to the improvement of eNOS function and the attenuation of oxidative stress. Ezetimibe treatment also significantly attenuated cardiac interstitial fibrosis and coronary arterial thickening of diabetic mice and ameliorated cardiac macrophage infiltration. This improvement of cardiac injury was also related to the attenuation of NADPH oxidase-mediated oxidative stress. Furthermore, ezetimibe significantly prevented hepatic steatosis, inflammation, and oxidative stress in diabetic mice. Our work provides the first evidence that ezetimibe prevented cardiovascular injury and hepatic steatosis in diabetic mice. These beneficial effects were attributed to the attenuation of oxidative stress and inflammation and the improvement of eNOS function. Therefore, we propose that ezetimibe may be a promising therapeutic drug for obese and type 2 diabetes.

N-Confused Porphyrin-aza-Dipyrrin Chimera: A Versatile Metal Coordination Ligand Using its Unique NH Tautomerism.

A novel N-confused porphyrin (NCP) analogue bearing an external aza-dipyrrin-like coordination site was synthesized by a Schiff-base forming reaction of N-confused oxoporphyrin and 2-aminopyridine derivatives. The chimera molecule enhances the intrinsic NH tautomerism of NCP to enable four possible tautomeric structures, three of which were identified by metal coordination.

Excess salt causes cerebral neuronal apoptosis and inflammation in stroke-prone hypertensive rats through angiotensin II-induced NADPH oxidase activation.

BACKGROUND AND PURPOSE: The precise mechanism of salt-induced brain injury is unclear. We examined the detailed causative role of angiotensin II and NADPH oxidase in salt-accelerated brain injury of stroke-prone spontaneously hypertensive rats (SHRSP). METHODS: We examined the effect of salt loading on brain reactive oxygen species (ROS), inflammation, and apoptosis in SHRSP. Salt-loaded SHRSP were given vehicle, valsartan (an angiotensin AT1 receptor blocker), or hydralazine to compare their efficacy on brain injury. We also examined the efficacy of apocynin (a NADPH oxidase inhibitor) on brain injury of salt-loaded SHRSP. RESULTS: Cerebral NADPH oxidase activity and ROS in SHRSP were already increased at 1 week after salt loading followed by the significant increase in ED-1-positive cells and neuronal apoptosis. Thus, cerebral NADPH oxidase activation preceded cerebral inflammation and neuronal apoptosis. Despite comparable hypotensive effects between valsartan and hydralazine in salt-loaded SHRSP, valsartan reduced cerebral NADPH oxidase activity and ROS more than hydralazine being accompanied by more prevention of stroke by valsartan than hydralazine. Valsartan, but not hydralazine, prevented neuronal apoptosis, being associated with the suppression of apoptosis signal-regulating kinase 1 activation by valsartan. Moreover, cerebral inflammation was also prevented by valsartan more than hydralazine, being associated with more suppression of monocyte chemotactic protein-1 and tumor necrosis factor-alpha expressions by valsartan. Thus, angiotensin II was directly involved in salt-induced neuronal NADPH oxidase activation, ROS, apoptosis, and inflammation in SHRSP. Apocynin attenuated the enhancement of ROS, cerebral inflammation, neuronal apoptosis, and apoptosis signal-regulating kinase 1 activation and prevented stroke in salt-loaded SHRSP, indicating the causative role of cerebral NADPH oxidase in salt-induced brain injury. CONCLUSIONS: We obtained the evidence that excess salt, through ROS produced by angiotensin II-activated NADPH oxidase, caused cerebral neuronal apoptosis and inflammation as well as stroke in SHRSP.

A Q312X mutation in the hemojuvelin gene is associated with cardiomyopathy due to juvenile haemochromatosis.

BACKGROUND AND AIMS: Juvenile haemochromatosis (JH) is an autosomal recessive iron disorder characterized by the early onset of secondary cardiomyopathy. The candidate modifier genes are hemojuvelin (HJV) and hepcidin antimicrobial peptide (HAMP). In the Japanese population, the prevalence of JH is quite low. The influence of HJV mutation on the JH phenotype is still unclear. METHODS AND RESULTS: We searched for possible mutations in a Japanese family with 2 members who were JH patients with severe heart failure. To search for possible variants in the HJV and HAMP genes, we performed direct sequencing in the family members. A homozygous nonsense mutation in exon 4 of HJV (Q312X) was identified in the JH patients and their mother. Three individuals in the family were heterozygous for this mutation. Subsequently, we evaluated the frequency of Q312X mutation in a large population (n=361) without heart failure, using allele-specific real-time PCR assay. No Q312X mutation was detected in this population. In the patients with the homozygous HJV mutation, iron loading revealed high serum ferritin concentration with accompanying elevated transferrin iron saturation. In contrast, ferritin levels were within the normal range in individuals with the heterozygous mutation. CONCLUSIONS: We found a nonsense mutation in the HJV gene. This mutation elevates ferritin levels and leads to JH associated with severe cardiomyopathy.

Methamphetamine-induced dopaminergic neurotoxicity is regulated by quinone-formation-related molecules.

Recently, the neurotoxicity of dopamine (DA) quinone formation by auto-oxidation of DA has focused on dopaminergic neuron-specific oxidative stress. In the present study, we examined DA quinone formation in methamphetamine (METH)-induced dopaminergic neuronal cell death using METH-treated dopaminergic cultured CATH.a cells and METH-injected mouse brain. In CATH.a cells, METH treatment dose-dependently increased the levels of quinoprotein (protein-bound quinone) and the expression of quinone reductase in parallel with neurotoxicity. A similar increase in quinoprotein levels was seen in the striatum of METH (4 mg/kg X4, i.p., 2 h interval)-injected BALB/c mice, coinciding with reduction of DA transporters. Furthermore, pretreatment of CATH.a cells with quinone reductase inducer, butylated hydroxyanisole, significantly and dose-dependently blocked METH-induced elevation of quinoprotein, and ameliorated METH-induced cell death. We also showed the protective effect of tyrosinase, which rapidly oxidizes DA and DA quinone to form stable melanin, against METH-induced dopaminergic neurotoxicity in vitro and in vivo using tyrosinase null mice. Our results indicate that DA quinone formation plays an important role, as a dopaminergic neuron-specific neurotoxic factor, in METH-induced neurotoxicity, which is regulated by quinone formation-related molecules.

Behavioral changes following antisense oligonucleotide-induced reduction of organic cation transporter-3 in mice.

The organic cation transporter-3 (OCT3) can transport monoamines, similar to neuronal monoamine transporters. Due to the lack of selective ligands, however, the functional role of OCT3 is still unknown. Thus, we investigated behavioral effects of antisense against OCT3 (AS) in mice. AS (0.075-0.25 microg/0.25 microl/h, for 7 days) dose-dependently decreased immobility time. Moreover, although neither AS (0.075 microg/0.25 microl/h, for 7 days) or imipramine (4 mg/kg, i.p.) were effective, imipramine (4 mg/kg, i.p.) significantly decreased immobility time in mice treated with AS (0.075 microg/0.25 microl/h, for 7 days). Additionally, AS (0.25 microg/0.25 microl/h, for 7 days) significantly increased locomotor activity induced by methamphetamine (1 mg/kg, s.c.), but did not affect spontaneous locomotor activity. These results suggest that OCT3 might become a novel molecular target to treat depression and other diseases related to monoaminergic neuronal systems.

Effects of edaravone on reperfusion injury in patients with acute myocardial infarction.

This clinical pilot study was a randomized, controlled, open-label study in 80 patients with acute myocardial infarction and was designed to examine the effects of a novel free radical scavenger, edaravone. Administration of edaravone before myocardial reperfusion was associated with smaller enzymatic infarcts and better clinical outcome.

The altered disposition of methamphetamine in the model of methamphetamine-induced neurotoxicity.

Methamphetamine (METH) is a drug of abuse, causing neurotoxic effects in mammals. Many hypotheses have been proposed to explain the underlying mechanisms of METH-induced toxicity, based on neurochemical/neuroanatomical changes. However, the pharmacokinetic properties of METH in the METH-induced neurotoxic model have not yet been evaluated. Thus, we investigated plasma and tissue levels of METH in the METH-induced neurotoxic model. As a result, when METH is administered multiply (5 mg/kg 4 times at 2-h intervals) in male Wistar rats, plasma METH levels at the third and forth injections were significantly higher than those at the first. The tissue distributions of METH in the brain as well as in the kidney were significantly decreased in the third injections, suggesting the importance of decreased transport of METH into tissues. Alternatively, one week after the establishment of METH-induced neurotoxicity, plasma levels of METH were back to normal, although METH levels in brain microdialysates were significantly higher than those in normal animals. These results suggest that the altered pharmacokinetic properties of METH, due to the abnormal membrane transport/disposition of METH into both central and peripheral tissues, might partially affect the emergence of METH-induced neurotoxicity.

Apoptosis signal-regulating kinase 1 deficiency eliminates cardiovascular injuries induced by high-salt diet.

OBJECTIVES: High-salt diet is closely associated with the increase in cardiovascular events. However, the mechanism of high-salt-induced cardiovascular injury is unknown. The present study was undertaken to test our hypothesis that apoptosis signal-regulating kinase (ASK) 1 may be involved in salt-induced cardiovascular injury. METHODS: Wild-type and ASK1-/- mice were fed a low-salt or a high-salt diet for 10 weeks and the effects of high-salt diet on food intake, urinary volume and electrolyte excretion, and cardiovascular injury were compared between both groups of mice. RESULTS: High-salt diet in wild-type and ASK1-/- mice similarly increased food intake, water intake, urine volume, and urinary sodium excretion, and comparably decreased plasma renin activity and aldosterone. Thus, ASK1 appears to play a minor role in the increase in natriuresis and the decrease in plasma renin, and aldosterone caused by high-salt diet. High-salt diet enhanced the phosphorylation of cardiovascular ASK1 in wild-type mice. High-salt diet in wild-type mice enhanced cardiac transforming growth factor-ß1, interstitial fibrosis, coronary perivascular fibrosis, and inflammatory cell infiltration, and these changes were associated with the increase in cardiac superoxide and Nox2. ASK1 deficiency abolished the above-mentioned high-salt-induced cardiac injury. High-salt diet also caused the impairment of vascular endothelium-dependent relaxation by acetylcholine and increased vascular superoxide, and Nox2 in wild-type mice, whereas it did not cause vascular injury in ASK1-/- mice. CONCLUSION: ASK1 is implicated in cardiac inflammation and fibrosis, and vascular endothelial dysfunction caused by high-salt diet, through the enhancement of oxidative stress.

Vascular responses to 8-nitro-cyclic GMP in non-diabetic and diabetic mice.

BACKGROUND AND PURPOSE: 8-Nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), formed nitric oxide (NO)-dependently, is a physiological second messenger, yet little is known about its role in the pathophysiology of vascular diseases. To study the pharmacological activity of 8-nitro-cGMP in diabetic mice, we compared its effects on vascular reactivity of aortas from non-diabetic and diabetic mice. EXPERIMENTAL APPROACH: Vascular tension recording was performed in thoracic aortic rings from wild-type (C57BL/6), non-diabetic db/+ and obese/diabetic db/db mice. Endothelial NO synthase (eNOS) uncoupling and superoxide were tested by Western blot and dihydroethidium fluorescence respectively. KEY RESULTS: 8-Nitro-cGMP, at concentrations up to 10 µM, enhanced phenylephrine-induced contractions in aortas from C57BL/6 and db/+ mice, but not from db/db mice. This enhancement was not observed with 8-bromo-cGMP. Pretreatment of aortas from C57BL/6 and db/+ mice with l-NAME (100 µM), superoxide dismutase (100 U·mL(-1) ) or tiron (1 mM), abolished 8-nitro-cGMP-induced enhancement of the phenylephrine contraction. In 8-nitro-cGMP (10 µM)-treated C57BL/6 aortas, eNOS dimer/monomer ratio was significantly decreased and vascular superoxide production increased, suggesting that 8-nitro-cGMP-induced superoxide production via eNOS uncoupling may mediate the enhancement of the phenylephrine contraction. At higher concentrations (>10 µM), 8-nitro-cGMP produced relaxation of the phenylephrine-contracted aortas from C57BL/6, db/+ and db/db mice. The 8-nitro-cGMP-induced relaxation in db/db mouse aortas was found to be resistant to a phosphodiesterase 5 inhibitor, zaprinast (1 µM). CONCLUSIONS AND IMPLICATIONS: The vasodilator effect of 8-nitro-cGMP may contribute to amelioration of the vascular endothelial dysfunction in diabetic mice, representing a novel pharmacological approach to prevent the complications associated with diabetes.

Eplerenone potentiates protective effects of amlodipine against cardiovascular injury in salt-sensitive hypertensive rats.

The clinical value of the combination of amlodipine and eplerenone is unclear. This study was undertaken to test whether eplerenone potentiates the protective effects of amlodipine against hypertensive cardiovascular injury. Salt-loaded Dahl salt-sensitive hypertensive rats (DS rats) were given (1) vehicle, (2) an antihypertensive dose of amlodipine, (3) a non-antihypertensive dose of eplerenone or (4) combined amlodipine and eplerenone for 6 weeks, and the effects on cardiovascular injuries were compared. There was no significant difference among the four groups regarding plasma aldosterone, urine volume or urinary electrolytes. A subpressor dose of eplerenone markedly ameliorated vascular endothelial dysfunction, cardiac inflammation and fibrosis in DS rats to a similar degree as an antihypertensive dose of amlodipine. Addition of eplerenone to amlodipine, without affecting blood pressure, enhanced the improvement by amlodipine of vascular endothelial function, cardiac inflammation, fibrosis and diastolic dysfunction in DS rats. Additive beneficial effects of eplerenone were attributed to additive potentiation of eNOS and Akt phosphorylation and additive reduction of oxidative stress. Eplerenone significantly attenuated cardiovascular NADPH oxidase activity by reducing gp91(phox) upregulation and attenuated the upregulation of cardiovascular AT1 receptor, but amlodipine failed to affect them. Thus, the normalization by eplerenone of gp91(phox) and AT1 receptor upregulation seems to be at least partially responsible for the additive benefits of eplerenone in the prevention of hypertensive cardiovascular injury. The combination of amlodipine and eplerenone may be a promising therapeutic strategy for cardiovascular disease in salt-sensitive hypertension.

Potentiation by candesartan of protective effects of pioglitazone against type 2 diabetic cardiovascular and renal complications in obese mice.

OBJECTIVES: The efficacy of renin-angiotensin system (RAS) blockers on type 2 diabetes and its complications remains to be defined. This study was undertaken to test the hypothesis that candesartan may enhance the protective effects of pioglitazone against type 2 diabetes. METHODS: We compared the effects of pioglitazone, candesartan, and their combination on cardiorenal and vascular injury, diabetes, and tissue oxidative stress in obese and type 2 diabetic db/db mice, and also examined the effects of tempol, a superoxide dismutase (SOD) mimetic, on db/db mice to define the role of oxidative stress. RESULTS: The addition of candesartan to pioglitazone significantly potentiated the suppressive effects of pioglitazone on cardiac macrophage infiltration and interstitial fibrosis, and glomerular macrophage infiltration and sclerosis in db/db mice. These benefits of the combination of pioglitazone and candesartan in db/db mice were attributed to additive attenuation of cardiorenal oxidative stress, through the attenuation of NADPH oxidase or the restoration of Cu/Zn-SOD and EC-SOD. The combination of these drugs reversed vascular endothelial dysfunction in db/db mice more than either monotherapy, by causing more phosphorylation of eNOS. Candesartan slightly augmented the improvement of glucose tolerance by pioglitazone in db/db mice, and this additive effect was mediated by more attenuation of oxidative stress. CONCLUSIONS: Our work demonstrated that candesartan significantly potentiated the protective effects of pioglitazone against cardiorenal and vascular injury, and diabetes in obese type 2 diabetic mice. Thus, the combination of pioglitazone with candesartan is potentially a promising therapeutic strategy for type 2 diabetes.

Benidipine, a dihydropyridine L-type/T-type calcium channel blocker, affords additive benefits for prevention of cardiorenal injury in hypertensive rats.

OBJECTIVES: Benidipine is a dihydropyridine calcium channel blocker inhibiting not only L-type but also T-type calcium channels. To elucidate potential additive benefit of benidipine for prevention of cardiorenal injury, we compared the cardiac and renal protective effects of equihypotensive doses of benidipine and cilnidipine in stroke-prone spontaneously hypertensive rats (SHRSP). METHODS: SHRSP were divided into five groups, and were given vehicle, benidipine at 1 or 3 mg/kg per day, or cilnidipine at 1 or 3 mg/kg per day for 7 weeks, and the protective effects against cardiorenal injury were compared among each group. RESULTS: Benidipine and cilnidipine at the same doses exerted comparable hypotensive effects on SHRSP throughout the treatment. Despite equihypotensive effects between both drugs, benidipine prevented cardiac hypertrophy, fibrosis, and inflammation to a greater extent than cilnidipine. Moreover, benidipine prevented glomerulosclerosis, tubulointerstitial injury, and renal inflammation more than cilnidipine. To elucidate the underlying mechanism of more beneficial effects of benidipine than cilnidipine, we compared the effects of these drugs on cardiac and renal oxidative stress, and aldosterone in SHRSP. Benidipine reduced both cardiac and renal NADPH oxidase activities in SHRSP more than cilnidipine, being associated with more attenuation of cardiac and renal superoxide by benidipine. Furthermore, serum aldosterone was significantly reduced by benidipine but not by cilnidipine. CONCLUSION: Benidipine exerted more protective effects against cardiorenal injury of hypertensive rats than cilnidipine, through more attenuation of oxidative stress than cilnidipine, and the reduction of aldosterone. Benidipine, via blockade of T-type calcium channels, seems to elicit additive benefits for prevention of hypertensive cardiorenal injury.

Aliskiren enhances protective effects of valsartan against type 2 diabetic nephropathy in mice.

OBJECTIVES: Addition of aliskiren, a direct renin inhibitor, to losartan provides additive reduction of urinary albumin excretion in type 2 diabetic patients. However, the detailed effect of aliskiren on type 2 diabetic nephropathy is still unknown. This study was undertaken to examine the efficacy of aliskiren and the combination of aliskiren with valsartan on type 2 diabetic nephropathy. METHODS: db/db mice were treated with aliskiren (3 mg/kg per day), valsartan (5 or 10 mg/kg per day), combined aliskiren (3 mg/kg per day) and valsartan (5 mg/kg per day), and hydralazine (80 mg/kg per day), for 6 weeks, and the protective effects against diabetic nephropathy were compared among each group. RESULTS: Aliskiren significantly attenuated albuminuria and glomerular mesangial matrix expansion in db/db mice, which was associated with the improvement of the increased glomerular transforming growth factor-beta and type IV collagen expressions, the increased macrophage infiltration, and the decreased glomerular nephrin expression of db/db mice. These protective effects of aliskiren in db/db mice were attributed to the attenuation of p22(phox)-related nicotinamide adenine dinucleotide phosphate oxidase-induced superoxide. Addition of aliskiren to valsartan treatment provided more beneficial effects on all the above-mentioned parameters than valsartan monotherapy. CONCLUSION: Aliskiren protected against type 2 diabetic nephropathy, through pleiotropic effects, and significantly enhanced the protective effects of valsartan against diabetic nephropathy in db/db mice.