Effect of the angiotensin II receptor antagonist olmesartan on morning home blood pressure in hypertension: HONEST study at 16 weeks.

Morning home blood pressure (BP) levels are more closely associated with cardiovascular risk than clinic BP levels. However, control of morning home BP has been worse than that of clinic BP in clinical practice. We examined the effects of olmesartan-based treatment using data (n=21 341) from the first 16 weeks of the Home BP measurement with Olmesartan Naive patients to Establish Standard Target blood pressure (HONEST) study, a prospective observational study for olmesartan-naive patients with essential hypertension. After 16-week olmesartan-based treatment, the clinic and morning home systolic BP (SBP) lowered from 151.6±16.4 and 153.6±19.0 mm Hg to 135.0±13.7 and 135.5±13.7 mm Hg, respectively (P<0.0001). The achievement percentage of target morning home SBP (<135 mm Hg) in all patients, those with diabetes mellitus (DM), and those with chronic kidney disease (CKD) increased from 13.5, 16.4 and 17.2% to 50.8, 47.9 and 48.8%, respectively, and the proportion of patients with well-controlled hypertension (clinic SBP<140 mm Hg and morning home SBP<135 mm Hg) increased from 7.9, 9.2 and 10.2% to 38.9, 34.5 and 36.3%, respectively. After 16-week olmesartan-based treatment, the proportion of patients with masked and white coat hypertension changed from 11.8 to 24.2% and 5.6 to 11.9%. In conclusion, both clinic and morning home BP in all, DM and CKD patients improved with 16-week olmesartan-based treatment in the 'real world', and the results showed a sustained 24-hour BP-lowering effect of olmesartan. Decrease in clinic and home BP resulted in an increased rate of masked and white coat hypertension, and further management is needed in those patients.

Blood pressure control status and effects of pravastatin on cardiovascular events occurrence in patients with dyslipidaemia.

Dyslipidaemia is often associated with hypertension, and many clinical trials have shown that lipid-lowering therapy and strict blood pressure (BP) control are important for preventing cardiovascular disease (CVD). However, few reports describe the effect of statins on CVD occurrence in relation to long-term BP control. In the present analysis, we investigated the effects of baseline BP and follow-up BP control on the occurrence of CVD in patients enrolled in the MEGA Study. We investigated whether BP values provide more accurate prediction of the occurrence of CVD, including cerebrovascular disease/transischemic attack (CVA/TIA), and the effect of pravastatin on CVA/TIA. The risk for CVA/TIA and other CVD increased significantly (P≤0.001) as the severity of hypertension increased. In contrast, pravastatin reduced the onset of CVA/TIA, regardless of the BP controlled. The mean BP was a more accurate predictor of CVD than a one-time BP value. In patients with mild-to-moderate dyslipidaemia, elevated BP increases the risk for CVA/TIA and other CVD, and rigorous BP control was important for preventing CVD, in particular CVA/TIA. The 12-month mean BP is useful to avoid attenuation to determine the association between CVD and BP. Pravastatin prevented CVA/TIA, regardless of BP controlled.

Dwarfism and cytochrome P450-mediated C-6 oxidation of plant steroid hormones.

BRs (brassinosteroids) are plant steroid hormones that are essential for normal plant development. The dramatic dwarfism exhibited by mutants in the CYP (cytochrome P450) enzymes involved in BR biosynthesis indicates a role for these hormones in plant growth and development. Since the mid-1990s, collaborative research has been geared towards developing a better understanding of the CYP85 class of CYPs involved in BR biosynthesis in both Arabidopsis and tomato. Some of the most recent observations include the fact that certain CYP85 CYPs catalyse the synthesis of the most bioactive BR, BL (brassinolide). Current evidence suggests that evolution of this function may have occurred independently in different dicotyledonous species. Interestingly, BL accumulates in tomato fruits, highlighting a key role for this hormone in fruit development. At the same time as developing a better understanding of the enzymatic function of these CYPs, we have also carried out experiments towards characterizing where and when these genes are expressed and mechanisms of their regulation. As expected for a hormone involved in growth and development, biosynthetic gene promoter activity is associated with young rapidly growing cells and with fruit development.

Molecular cloning and characterization of isomultiflorenol synthase, a new triterpene synthase from Luffa cylindrica, involved in biosynthesis of bryonolic acid.

An oxidosqualene cyclase cDNA, LcIMS1, was isolated from cultured cells of Luffa cylindrica Roem. by heterologous hybridization with cDNA of Glycyrrhiza glabra beta-amyrin synthase. Expression of LcIMS1 in yeast lacking endogenous oxidosqualene cyclase activity resulted in the accumulation of isomultiflorenol, a triterpene. This is consistent with LcIMS1 encoding isomultiflorenol synthase, an oxidosqualene cyclase involved in bryonolic acid biosynthesis in cultured Luffa cells. The deduced amino-acid sequence of LcIMS1 shows relatively low identity with other triterpene synthases, suggesting that isomultiflorenol synthase should be classified into a new group of triterpene synthases. The levels of isomultiflorenol synthase and cycloartenol synthase mRNAs, which were measured with gene-specific probes, correlated with the accumulation of bryonolic acid and phytosterols over a growth cycle of the Luffa cell cultures. Isomultiflorenol synthase mRNA was low during the early stages of cell growth and accumulated to relatively high levels in the late stages. Induction of this mRNA preceded accumulation of bryonolic acid. In contrast, cycloartenol synthase mRNA accumulated in the early stages of the culture cycle, whereas phytosterols accumulated at the same relative rate throughout the whole growth cycle. These results suggest independent regulation of these two genes and of the accumulation of bryonolic acid and phytosterols.

Cloning and characterization of a cDNA encoding beta-amyrin synthase involved in glycyrrhizin and soyasaponin biosyntheses in licorice.

An oxidosqualene cyclase cDNA, termed GgbAS1, was isolated from cultured cells of licorice (Glycyrrhiza glabra) by heterologous hybridization with cDNA of Arabidopsis thaliana LUP1 lupeol synthase. The yeast transformed with an expression vector containing the open reading frame of GgbAS1 produced beta-amyrin, indicating that GgbAS1 encodes beta-amyrin synthase involved in the glycyrrhizin and soyasaponin biosyntheses in licorice. Northern blot analysis showed that the level of beta-amyrin synthase mRNA was drastically changed in the cultured licorice cells, whereas the mRNA level of cycloartenol synthase was relatively constant.

Insulin-induced relaxation of rat mesenteric artery is mediated by Ca(2+)-activated K(+) channels.

We tested the hypothesis that relaxation of the rat mesenteric artery in response to insulin is mediated by K(+) channels. Two concentrations of insulin (10 and 100 mU/ml) induced relaxation of the artery by 6+/-1%, 24+/-3% (mean+/-S.E.M.). Denudation of the endothelium or precontraction by KCl (30 mM), clotrimazole (10 microM), a cytochrome P450 inhibitor, charybdotoxin (30 nM) an inhibitor of large-conductance Ca(2+)-activated K(+) channels, abolished the relaxation of the artery in response to insulin. However, N(omega)-nitro-L-arginine methyl ester (L-NAME; 100 microM), an inhibitor of nitric oxide synthase, apamin (1 microM), an inhibitor of small-conductance Ca(2+)-activated K(+) channels, or glibenclamide (10 microM), an ATP-sensitive K(+) channels blocker, did not attenuate the relaxation of the artery caused by insulin. These results suggest that the relaxation of rat mesenteric artery in response to insulin is mediated mostly by large-conductance Ca(2+)-activated K(+) channels, perhaps an endothelium-derived hyperpolarizing factor (EDHF).

Leisure-time physical activity and related lifestyle characteristics among middle-aged Japanese. Japan Lifestyle Monitoring Study Group.

The present study describes leisure-time physical activity status and related lifestyle factors in middle-aged Japanese. Data were obtained from 1,893 (905 men, 988 women) participants aged 40-69 years who had either been selected from a public registry or who had visited a healthcare facility. Subjects responded to a self-administered questionnaire and were interviewed using an assessment method for leisure-time and on-the-job physical activity within the last 12 months by trained interviewers. According to the leisure-time physical activity score, men and urban residents tended to engage in more leisure-time physical activity than did women and rural residents, respectively. Leisure-time physical activity tended to be inversely associated with on-the-job physical activity in all cases aside from women in urban regions, and also to be associated with higher levels of education in rural regions. Subjects engaging in more leisure-time physical activity had higher odds ratios of certain lifestyle factors, indicating a healthy lifestyle that included a variety of foods in their diet and a subjective sense of wellness in both men and women, in addition to non-smoking and drinking milk in men. These results suggested that leisure-time physical activity is influenced by socio-environmental factors, and that it is accompanied by other healthy behavior.

Close relationship of abnormal glucose tolerance with endothelial dysfunction in hypertension.

Hypertension is frequently accompanied by left ventricular hypertrophy, endothelial dysfunction, and abnormal glucose metabolism. However, no study has examined the relative pathological significance of left ventricular hypertrophy and abnormal glucose metabolism on endothelial dysfunction in hypertension. This study was conducted to evaluate whether abnormal glucose tolerance assessed by 75-g oral glucose tolerance test or left ventricular hypertrophy is more closely associated with endothelial dysfunction in never-treated hypertensive patients without elevated fasting blood glucose. We studied 107 unmedicated hypertensive patients (mean age, 54+/-10 years) whose fasting blood glucose was <7.0 mmol/L. Endothelial function was assessed by change in brachial artery diameter in response to reactive hyperemia, and left ventricular mass index was determined by ultrasonography. Simple linear regression analysis demonstrated that endothelial function significantly correlated with left ventricular mass index and 2-hour blood glucose in 75-g oral glucose tolerance test, but not with fasting blood glucose. Multiple linear regression analysis revealed that endothelial function significantly correlated with 2-hour blood glucose (beta=-2.68, P<0.05) after we controlled for other clinical variables. Patients were divided into 3 groups according to 2-hour blood glucose levels. Endothelial function was more impaired in patients with diabetes (n=12; 4.7+/-1.8%) and in those with impaired glucose tolerance (n=31; 6.3+/-2.9%) than in those with normal glucose tolerance (n=64; 8.4+/-4.5%) (P<0.05), but left ventricular mass index was similar in these 3 groups. Abnormal glucose tolerance assessed by 75-g oral glucose tolerance test, rather than left ventricular hypertrophy, may have direct pathophysiological relevance to endothelial dysfunction in borderline to moderate hypertensive patients.

Molecular cloning and functional expression of triterpene synthases from pea (Pisum sativum) new alpha-amyrin-producing enzyme is a multifunctional triterpene synthase.

Ursane type triterpene is one of the most widespread triterpene aglycones found in plants, together with oleanane type, and these two types often occur together in the same plant. Pisum sativum is known to produce both types of triterpenes. Homology based PCRs with degenerate primers designed from the conserved sequences found in the known beta-amyrin synthases have resulted in cloning of two triterpene synthase cDNAs from immature seeds of P. sativum. They show high sequence identities to each other (78%) and also to the known beta-amyrin synthases (70-90%). ORFs of the full-length clones named as PSY (2277 bp, codes for 759 amino acids) and PSM (2295 bp, codes for 765 amino acids) were ligated into the yeast expression vector pYES2 under the control of GAL1 promoter. Heterologous expression in yeast revealed PSY to be a P. sativum beta-amyrin synthase. Surprisingly, however, PSM turned out to be a novel mixed amyrin synthase producing both alpha- and beta-amyrin. Several minor triterpenes were also identified as the PSM byproducts. The presence of such multifunctional triterpene synthase would account for the co-occurence of ursane and oleanane type triterpenes in plants.

Molecular cloning and characterization of a cDNA for Glycyrrhiza glabra cycloartenol synthase.

A cDNA clone (GgCAS1) encoding cycloartenol synthase (CAS) has been isolated from Glycyrrhiza glabra (licorice) by cross-hybridization with that of Pisum sativum CAS as a probe. The deduced amino acid sequence of GgCAS1 exhibits 89%, 83% and 81% identity to those of Pisum sativum, Panax ginseng and Arabidopsis thaliana CASs, respectively. CAS activity has been detected in the homogenate of the yeast transformed with the expression vector containing the open reading frame of GgCAS1. Southern blot analysis suggested that at least two CAS genes exist in the licorice genome. In Northern blot analysis, the strong signal for CAS mRNA is detected in the cultured licorice cells of all growth phases, but no significant increase of CAS mRNA expression was observed in the cells treated with the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor, pravastatin.

[The effect of exogenous nitric oxide on endothelial dysfunction in two-kidney, one-clip renovascular hypertensive rats].

Previous studies have shown that hypertension causes endothelial dysfunction. To study the influence of exogenous nitric oxide(NO) on endothelial dysfunction produced by hypertension, we administered a non-depressor dose of nipradilol to two-kidney, one-clip renovascular hypertensive rats(2K1C). Sprague-Dawley rats underwent either sham surgery(G-1) or clipping of the left renal artery. From day seven, 2K1C were randomized into 3 groups, placebo treatment(G-2), nipradilol treatment(G-3,) and propranolol treatment(G-4). Urinary NO2- + NO3-(NOx) excretion (UNOx V) was measured 4 weeks after clipping, and then, acetylcholine(Ach), A23187, or sodium nitroprusside(SNP)-induced relaxation were measured in the aorta. Blood pressure was increased in G-2, G-3, and G-4 compared to G-1. UNOx V was lower in G-2, G-3, and G-4 compared to G-1, but UNOx V was higher in G-3 compared to G-2 and G-4. Although Ach or A23187-induced relaxation was significantly decreased in isolated artery from G-2, G-3, and G-4 compared with those from G-1. Ach- or A23187-induced relaxation was improved in G-3. SNP-induced relaxation did not differ among the 4 groups. These results suggest that exogenous NO from nipradilol reduces the endothelial dysfunction caused by hypertension without changing the blood pressure.

[Role of endothelium-derived hyperpolarizing factor in insulin-induced vasodilation in rat mesenteric artery].

Endothelium-derived hyperpolarizing factor (EDHF) as a factor in blood pressure regulation has received attention recently. However, its role in insulin-induced vasodilation is not clear. We investigated the mechanism of vasodilation induced by insulin in vitro using mesenteric arteries isolated from normotensive rats. The 2nd branch of the mesenteric artery was isolated from male Sprague-Dawley rats (12-14 weeks old), mounted on microcannules in a chamber and perfused with Krebs solution. The diameter of this segment was measured continuously with a video system under the following conditions: intraluminal insulin administration (10 and 100 mU/ml) with and without pretreatment by denudation, N omega-methyl-L-arginine methyl ester (L-NAME), indomethacin, tetrabuthylammonium (TBA, non-specific Ca2+ activated K channel blocker), charybdotoxin (ChTx, large-conductance Ca2+ activated K channel blocker), apaminn (small-conductance Ca2+ activated K channel blocker) or Na+/k(+)-ATPase blocker (ouabain). Insulin treatment induced dose-dependent vasodilation. The effects of insulin were significantly suppressed by denudation, TBA, apamin, and ChTx. L-NAME, indomethacin and ouabain did not influence the insulin-induced vasodilation. Results suggested that insulin dilates small arteries by activating the Ca2+ activated K channel.

[Effects of angiotensin II receptor antagonist on insulin sensitivity and sympathetic activity in spontaneously hypertensive rats].

Although angiotensin AT1 receptor antagonist(AT1 A) improves insulin sensitivity in insulin resistant models, its effect on spontaneously hypertensive rats(SHR) has not been elucidated. We investigated the effects of AT1 A, candesartan on insulin sensitivity in SHR/Izm and the role of sympathetic activity in its mechanism. In 9-week-old SHR/Izm, candesartan(10 mg/kg/day) was given orally for 5 days. A control group received vehicle. On the 6th day, mean arterial pressure (MAP), heart rate(HR), plasma norepinephrine (PNE), plasma epinephrine(PE) and plasma dopaminc(PDA) were measured in both groups (n = 11 in each group). In the separate groups of rats, fasting blood glucose (FBG), serum sodium, serum potassium and insulin sensitivity by steady state blood glucose (SSBG) were assessed (n = 16 in the Candesartan group and n = 8 in the Control group). MAP and SSBG were significantly lower in the Candesartan group (117 +/- 2 mmHg and 138 +/- 5 mg/dl) than those in the Control group(155 +/- 6 mmHg and 164 +/- 10 mg/dl). Body weight, HR, FBG, PNE, PE, PDA, sodium and potassium were the same between the groups. In conclusion, since AT1 A, candesartal lowers blood pressure and improves insulin sensitivity irrespective of sympathetic activity in SHR/Izm, it is useful in treating hypertension associated with insulin resistance.

Lipoxygenase inhibition decreases neointimal formation following vascular injury.

Our aim was to assess the potential role of lipoxygenase (LO) products in neointimal formation following vascular injury. We investigated the effect of LO pathway inhibition, by phenidone, on the concentration of 12- and 5-hydroxyeicosatetraenoic acid (12- and 5-HETE) in rat whole blood and in aortic tissue. We also examined the effect of phenidone on myoneointimal formation in balloon-injured rat carotid arteries. Phenidone significantly decreases the concentration of HETEs in aortic tissue, and decreases neointimal size even though there is no difference in the BrdU index. These data indicate that the LO product participates in developing neointima following balloon-induced vascular injury, and that the LO blocker phenidone decreases neointimal size possibly by suppressing migration of smooth muscle cells.

Two branches of the lupeol synthase gene in the molecular evolution of plant oxidosqualene cyclases.

Two new triterpene synthase cDNAs, named as OEW and TRW, were cloned from olive leaves (Olea europaea) and from dandelion roots (Taraxacum officinale), respectively, by the PCR method with primers designed from the conserved sequences found in the known oxidosqualene cyclases. Their ORFs consisted of 2274 bp nucleotides and coded for 758 amino acid long polypeptides. They shared high sequence identity (78%) to each other, while they showed only about 60% identities to the known triterpene synthases LUPI (lupeol synthase clone from Arabidopsis thaliana) and PNY (beta-amyrin synthase clone from Panax ginseng) at amino acid level. To determine the enzyme functions of the translates, they were expressed in an ERG7 deficient yeast mutant. Accumulation of lupeol in the cells of yeast transformants proved both of these clones code for lupeol synthase proteins. An EST (expression sequence tag) clone isolated from Medicago truncatula roots as a homologue of cycloartenol synthase gene, exhibits high sequence identity (75-77%) to these two lupeol synthase cDNAs, suggesting it to be another lupeol synthase clone. Comparatively low identity (approximately 57%) of LUP1 from Arabidopsis thaliana to either one of these clones leaves LUP1 as a distinct clone among lupeol synthases. From these sequence comparisons, now we propose that two branches of lupeol synthase gene have been generated in higher plants during the course of evolution.

Effect of insulin resistance on the endothelial vasomotor function of the coronary artery of nondiabetic patients.

Attention has been paid to the relationship between insulin resistance and coronary artery disease. The present study investigated the relationship between insulin resistance and the endothelial vasomotor function of the coronary artery of nondiabetic patients with chest pain and a positive exercise tolerance test. Twenty-five nondiabetic patients with chest pain were included. Patients with a steady state plasma glucose (SSPG) level of greater than or equal to 135 mg/dl were placed in the insulin resistant (IR) group, and those with a SSPG level less than 135 mg/dl were placed in the noninsulin resistant (NIR) group. The effect of acetylcholine, papaverine, and isosorbide dinitrate on the vasomotor response of the coronary endothelium was studied. The percent change in diameter of the coronary artery after injection of acetylcholine (20 microg ml(-1) min(-1)) was 84+/-17% in the IR group, and 109+/-18% in the NIR group. The difference in the degree of the vasodilative response is statistically significant (p<0.01). The percent change in coronary flow velocity after injection of acetylcholine (20 microg ml(-1) min(-1)) in the IR group was 120+/-67%, whereas that in the NIR group was 256+/-58%; the increase in coronary artery flow velocity of the IR group was significantly smaller than that of the NIR group (p<0.01). Nondiabetic patients with insulin resistance have endothelial vasomotor dysfunction, which raises an important question as to whether nondiabetic patients with insulin resistance should be treated to prevent the development of coronary heart disease.

Biosynthesis of 20-hydroxyecdysone in Ajuga hairy roots: fate of 6alpha- and 6beta-hydrogens of lathosterol.

The fate of 6alpha- and 6beta-hydrogens of lathosterol during the transformation into 20-hydroxyecdysone was chased by feeding [3alpha,6beta-2H2]- and [3alpha,6alpha-2H2]-lathosterols to hairy roots of Ajuga reptans var. atropurpurea. The behavior of 6beta-hydrogen, which mostly migrated to the C-5 position of 20-hydroxyecdysone, was in agreement with that of C-6 hydrogen of cholesterol. The results strongly supported the view that cholesterol and lathosterol are first metabolized into 7-dehydrocholesterol, which is then converted into 20-hydroxyecdysone via 7-dehydrocholesterol 5alpha,6alpha-epoxide in the hairy roots.