Search PubMed⌕ Search

Biomedical subjects

Y Kaneshiro

Publications and source records attributed to Y Kaneshiro.

10 recordsLinked to original sources
PubMed2006

Effects of amlodipine and valsartan on vascular damage and ambulatory blood pressure in untreated hypertensive patients.

The present study was performed to compare the long-term effects of 24-h ambulatory blood pressure (BP) control with amlodipine versus valsartan on vascular damage in untreated hypertensive patients. Amlodipine and valsartan have benefits on cardiovascular mortality and morbidity in hypertensive patients. Although ambulatory BP is associated with severity of target-organ damage in hypertensive patients, beneficial effects of ambulatory BP control with amlodipine versus valsartan on vascular damage have not been compared. Pulse wave velocity (PWV), intima-media thickness (IMT) of the carotid arteries, urinary albumin excretion (UAE) and 24-h ambulatory BP were determined in 100 untreated hypertensive patients before and 12 months after the start of antihypertensive therapy with amlodipine or valsartan. Amlodipine and valsartan decreased ambulatory BP similarly, but the variability of 24-h and daytime ambulatory systolic BP was significantly reduced by amlodipine but not by valsartan. The reduced variability of ambulatory systolic BP caused by amlodipine significantly contributed to the improvement of PWV, although both drugs decreased PWV similarly. Carotid IMT was unaffected by treatment with either drug. Valsartan significantly decreased UAE independently of its depressor effect, but amlodipine had no effect on UAE. These results suggest that the 24-h control of ambulatory BP with amlodipine had functionally improved the stiffened arteries of hypertensive patients by the end of 12 months of treatment, in part through reducing BP variability, whereas ambulatory BP control with valsartan decreased the arterial stiffness to the same degree as amlodipine without affecting BP variability maybe through some pleiotropic effects.

Amlodipine↗
PubMed2006

Ambulatory blood pressure variability and brachial-ankle pulse wave velocity in untreated hypertensive patients.

Blood pressure (BP) variability is estimated as the standard deviation of 24-h ambulatory BP. The present study was performed to determine the effect of the mean 24-h ambulatory BP values and standard deviations on arterial wall stiffness assessed by brachial-ankle pulse wave velocity (baPWV). Brachial-ankle pulse wave velocity, carotid intima-media thickness (IMT), urinary albumin excretion (UAE) and 24-h ambulatory BP were measured before the start of antihypertensive therapy in 203 newly diagnosed hypertensive patients (53.3+/-0.7 years old; clinic systolic/diastolic BP: 154+/-1/98+/-1 mm Hg), and univariate and multivariate regression analyses of these clinical and biological parameters were performed. Univariate regression analyses revealed a significant association between mean baPWV values and the standard deviations of ambulatory systolic/diastolic BP. Mean ambulatory systolic/diastolic BP values were also associated with UAE, and the standard deviations of ambulatory systolic BP were associated with maximum carotid IMT. Quintile analyses showed that patients with a mean 24-h ambulatory mean BP value and standard deviation below 110 and 20 mm Hg, respectively, had the lowest baPWV. Moreover, the multivariate regression analyses confirmed a significant correlation between baPWV and the standard deviation of 24-h ambulatory systolic BP. In conclusion, untreated hypertensive patients with a higher 24-h ambulatory systolic BP variability had stiffer arterial walls. Ambulatory systolic BP variability may be involved in stiffening of the arteries of hypertensive patients.

Aged↗
PubMed2006

Increased expression of cyclooxygenase-2 in the renal cortex of human prorenin receptor gene-transgenic rats.

Increased macula densa cyclooxygenase-2 (COX-2) is observed in diabetic rats and may contribute to hyperfiltration states. However, the signals mediating increased COX-2 expression in diabetic rats remain undetermined. We recently found that non-proteolytic activation of prorenin by site-specific binding proteins, such as prorenin receptor, plays a pivotal role in the development of diabetic nephropathy. The present study was designed to determine the contribution of prorenin receptor to renal cortical COX-2 expression. The COX-2 mRNA and protein levels of six 4-week-old male wild-type rats and six human prorenin receptor gene-transgenic (hProRenRcTg) rats were measured by real-time polymerase chain reaction methods, Western blotting, and immunohistochemistry, and compared. There were no differences between the two groups in arterial pressure measured by telemetry, urinary sodium excretion, or renal levels of rat prorenin receptor mRNA. The renal cortical COX-2 mRNA levels of the hProRenRcTg rats were significantly higher than those of the wild-type rats, and the renal cortical COX-2 protein levels were also higher in hProRenRcTg rats than in the wild-type rats. Immunohistochemical analysis revealed that COX-2 immunostaining was predominantly present in the macula densa cells, and significantly more COX-2-positive cells were present in the hProRenRcTg rats than in the wild-type rats. In addition, COX-2 inhibition with NS398 significantly decreased renal cortical blood flow in the hProRenRcTg rats but not in the wild-type rats. These results strongly suggest that human prorenin receptor directly or indirectly contributes to the regulation of renal cortical COX-2 expression.

Animals↗
PubMed2005

Long-term effects of statins on arterial pressure and stiffness of hypertensives.

Although lowering blood pressure (BP) reduces aortic stiffness, achieving the recommended BP goal can be difficult. Recent studies have shown that short-term use of statins can reduce BP significantly. To determine the long-term effects of statins on BP and aortic stiffness, a single-blind randomized prospective study was performed on 85 hyperlipidaemic hypertensive patients whose BP was insufficiently controlled by antihypertensive therapy. Every 3 months, aortic stiffness was assessed by measuring pulse wave velocity (PWV). Patients were randomly allocated to groups treated with pravastatin, simvastatin, fluvastatin, or a nonstatin antihyperlipidaemic drug. No significant differences in patient characteristics, kinds of antihypertensive drugs, BP, ankle brachial index, PWV, or serum lipid, creatinine, or C-reactive protein levels were found between the four groups at the start of the study. During the 12-month treatment period, PWV did not change in the pravastatin group or nonstatin group, but it was transiently reduced in the simvastatin group and significantly decreased in the fluvastatin group, even though the doses of the statins used in this study were lower than the usually prescribed dose. All four antihyperlipidaemic drugs significantly decreased serum cholesterol levels without affecting BP, ankle brachial index, or serum triglyceride levels. The C-reactive protein serum levels decreased significantly in the three statin groups but not in the nonstatin group. These results suggest that long-term use of fluvastatin by hyperlipidaemic hypertensive patients is associated with a significant reduction in aortic stiffness without any effect on BP.

Anticholesteremic Agents↗
PubMed1998

Total parenteral nutrition supplemented with medium-chain triacylglycerols prevents atrophy of the intestinal mucosa in septic rats.

Total parenteral nutrition (TPN) is associated with an increased incidence of bacterial translocation (BT) compared with enteral nutrition because of the disuse atrophy of the intestine. In this study, we assessed the effect of adding medium-chain triacylglycerols (MCT) to TPN for the prevention of mucosal atrophy in the intestine. Rats were subjected to either fat-free TPN, TPN with long-chain triacylglycerols (LCT), or TPN with MCT for 5 d and nutrition parameters were evaluated. In another set of rats receiving the same TPN regimen, 0.8 or 0.05 mg/kg endotoxin was administered on day 4. Survival was evaluated and BT to the mesenteric lymph nodes, liver, and systemic blood was measured 24 h later. The mucosal heights of the jejunum and ileum were evaluated concurrently. The survival rate was significantly improved in the MCT group (P < 0.05) at the endotoxin dose of 0.8 mg/kg. The nutrition condition presented by phospholipid, total cholesterol, and total ketone body levels was the best in the MCT group compared to the other groups. The intestinal villous height in the ileum was significantly greater in the MCT group. However, the improvement of BT in MCT group was not statistically significant. In this endotoxin-challenged rat model, survival rate was improved by the supplementation of MCT. This effect may be presented in some part by the improvement in nutrition condition and by the prevention of mucosal atrophy in the intestine.

Animals↗
PubMed1998

Augmentation of mitochondrial reduced glutathione by S-adenosyl-L-methionine administration in ischemia-reperfusion injury of the rat steatotic liver induced by choline-methionine-deficient diet.

We examined whether warm ischemia-reperfusion (I/R) damage of the rat steatotic liver can be reduced by administration of S-adenosyl-L-methionine (SAMe). We examined the effect of SAMe on the mitochondrial reduced-glutathione (GSH) pool. Sixty minutes of partial left lobar vascular clamping followed by 2 h of reperfusion were employed for a model of hepatic warm ischemia. Either 5% dextrose or SAMe was injected intraperitoneally 2 h before I/R in steatotic rats (S-D5% or S-SAMe group). Serum liver enzyme concentrations 2 h after reperfusion were significantly lower in the S-SAMe group than in the S-D5% group. The cytosolic and mitochondrial GSH concentrations after I/R were significantly higher in the S-SAMe group than in the S-D5% group (p < 0.05). The cytosolic and mitochondrial oxidized-glutathione/GSH ratios after I/R were significantly greater in the S-D5% group than in the S-SAMe group (p < 0.01). The adenosine triphosphate concentration was higher in the S-SAMe group than in the S-D5% group (p = 0.0515). These results show that hepatocellular and mitochondrial oxidative stress after I/R in the steatotic liver can be reduced by administration of SAMe. The results also show that mitochondrial function and hepatocellular integrity can be restored by administration of SAMe in steatotic rats.

Animals↗