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Biomedical subjects

Hitonobu Tomoike

Publications and source records attributed to Hitonobu Tomoike.

At least 19 recordsLinked to original sources
PubMed2007

Prolonged transient acidosis during early reperfusion contributes to the cardioprotective effects of postconditioning.

We have previously reported that the prolonged transient acidosis during early reperfusion mediates the cardioprotective effects in canine hearts. Recently, postconditioning has been shown to be one of the novel strategies to mediate cardioprotection. We tested the contribution of the prolonged transient acidosis to the cardioprotection of postconditioning. Open-chest anesthetized dogs subjected to 90-min occlusion of the left anterior descending coronary artery and 6-h reperfusion were divided into four groups: 1) control group; no intervention after reperfusion (n = 6); 2) postconditioning (Postcon) group; four cycles of 1-min reperfusion and 1-min reocclusion (n = 7); 3) Postcon + sodium bicarbonate (NaHCO(3)) group; four cycles of 1-min reperfusion and 1-min reocclusion with the administration of NaHCO(3) (n = 8); and 4) NaHCO(3) group; administration of NaHCO(3) without postconditioning (n = 6). Infarct size, the area at risk (AAR), collateral blood flow during ischemia, and pH in coronary venous blood were measured. The phosphorylation of Akt and extracellular signal-regulated kinase (ERK) in ischemic myocardium was assessed by Western blot analysis. Systemic hemodynamic parameters, AAR, and collateral blood flow were not different among the four groups. Postconditioning induced prolonged transient acidosis during the early reperfusion phase. Administration of NaHCO(3) completely abolished the infarct size-limiting effects of postconditioning. Furthermore, the phosphorylation of Akt and ERK in ischemic myocardium induced by postconditioning was also blunted by the cotreatment of NaHCO(3). In conclusion, postconditioning mediates its cardioprotective effects possibly via prolonged transient acidosis during the early reperfusion phase with the activation of Akt and ERK.

Acidosis↗
PubMed2007

Association of genetic polymorphisms of ACADSB and COMT with human hypertension.

OBJECTIVES: Genetically hypertensive rats provide an excellent model to investigate the genetic mechanisms of hypertension. We previously identified three differentially expressed genes, Acadsb (short/branched chain acyl-CoA dehydrogenase), Comt (catecholamine-O-methyltransferase), and Pnpo (pyridoxine 5'-phosphate oxidase), in hypertensive and normotensive rat kidneys as potential susceptibility genes for rat hypertension. We examined the association of human homologues of these genes with human hypertension. METHODS: We sequenced three genes using samples from 48 or 96 hypertensive patients, identified single nucleotide polymorphisms, and genotyped them in a population-based sample of 1818 Japanese individuals (771 hypertensive individuals and 1047 controls). RESULTS: After adjustments for age, body mass index, present illness (hyperlipidaemia, diabetes mellitus), and lifestyle (smoking, alcohol consumption), multivariate logistic regression analysis revealed that -512A>G in ACADSB was associated with hypertension in women (AA vs AG + GG: odds ratio = 0.70, 95% confidence interval = 0.53-0.94). This single nucleotide polymorphism was in tight linkage disequilibrium with -254G>A. Furthermore, -1187G>C in COMT was associated with hypertension in men (GG vs CG + CC: odds ratio = 0.69, 95% confidence interval = 0.52-0.93) and was in tight linkage disequilibrium with 186C>T. After adjustments described above, -512 A>G and -254G>A in ACADSB were associated with variations in systolic blood pressure. ACADSB was in tight linkage disequilibrium with MGC35392 across a distance of 18.3 kb. COMT was not in linkage disequilibrium with any adjacent genes. Analysis indicated that two haplotypes of COMT were significantly associated with hypertension in men. CONCLUSION: Our study suggests the possible involvement of genetic polymorphisms in ACADSB and COMT in essential hypertension in the Japanese population.

Acyl-CoA Dehydrogenases↗
PubMed2006

Genotypes of vitamin K epoxide reductase, gamma-glutamyl carboxylase, and cytochrome P450 2C9 as determinants of daily warfarin dose in Japanese patients.

The dose required for the anticoagulant effect of warfarin exhibits large inter-individual variations. This study sought to determine the contribution of four genes, vitamin K epoxide reductase (VKORC1), gamma-glutamyl carboxylase (GGCX), calumenin (CALU), and cytochrome P450 2C9 (CYP2C9) to the warfarin maintenance dose required in Japanese patients following ischemic stroke. We recruited 93 patients on stable anticoagulation with a target International Normalized Ratio (INR) of 1.6-2.6. We genotyped eleven representative single nucleotide polymorphisms (SNPs) in the three genes involved in vitamin K cycle and the 42613A>C SNP in CYP2C9, known as CYP2C93, and then examined an association of these genotypes with warfarin maintenance doses (mean+/-SD=2.96+/-1.06 mg/day). We found an association of effective warfarin dose with the -1639G>A (p=0.004) and 3730G>A genotypes (p=0.006) in VKORC1, the 8016G>A genotype in GGCX (p=0.022), and the 42613A>C genotype in CYP2C9 (p=0.015). The model using the multiple regression analysis including age, sex, weight, and three genetic polymorphisms accounted for 33.3% of total variations in warfarin dose. The contribution to inter-individual variation in warfarin dose was 5.9% for VKORC1 -1639G>A, 5.2% for CYP2C9 42613A>C, and 4.6% for GGCX 8016G>A. In addition to polymorphisms in VKORC1 and CYP2C9, we identified GGCX 8016G>A, resulting in the missense mutation R325Q, as a genetic determinant of warfarin maintenance dose in Japanese patients.

Aged↗
PubMed2006

Hereditary postprandial hypertriglyceridemic rabbit exhibits insulin resistance and central obesity: a novel model of metabolic syndrome.

OBJECTIVE: We have established a hereditary postprandial hypertriglyceridemic (PHT) rabbit. The present study was designed to define whether this rabbit model represents both insulin resistance and central obesity. METHODS AND RESULTS: Body weight, abdominal circumference, visceral fat weight, and glucose tolerance were compared between PHT and Japanese white (JW) rabbit. Plasma levels of triglycerides (TG), total cholesterol (TC), glucose, and insulin were measured before and after feeding. Abdominal circumference of PHT rabbit was larger than that of JW rabbit, with no difference in body mass index. Visceral fat accumulation was noted as obvious in mesenterium, retroperitoneal space, and epididymal area. Plasma TG and TC levels were high preprandially and markedly increased postprandially in PHT rabbit compared with JW rabbit. Although plasma glucose levels were comparable in both groups, plasma insulin levels were elevated in PHT rabbit. Glucose tolerance tests indicated that plasma insulin levels in PHT rabbit were consistently higher than in JW rabbit. A positive correlation was observed between plasma insulin levels and visceral fat weight in PHT rabbit. CONCLUSIONS: PHT rabbit shows insulin resistance along with central obesity. PHT rabbit will serve as a model for elucidating genetic predisposition and pathophysiology in metabolic syndrome.

Animals↗
PubMed2006

Component analysis of HPLC profiles of unique lipoprotein subclass cholesterols for detection of coronary artery disease.

BACKGROUND: Patients with coronary artery disease (CAD) are known to have several lipoprotein abnormalities. We examined plasma cholesterol concentrations of major lipoproteins and their subclasses, using a gel permeation HPLC, to establish an association between a lipoprotein subclass pattern and the presence of CAD. METHODS: We performed a simple and fully automated HPLC, followed by mathematical treatment on chromatograms, for measuring cholesterol concentrations of major lipoproteins and their subclasses in 62 male patients (45 with CAD and 17 controls without CAD) who underwent cardiac catheterization. RESULTS: For major lipoprotein classes, the patient group had a significantly (P<0.05) higher LDL-cholesterol (LDL-C) and lower HDL-cholesterol (HDL-C), but no difference in VLDL-cholesterol (VLDL-C) concentrations. For lipoprotein subclasses, the patient group had a significantly higher small VLDL-C (mean particle diameter of 31.3 nm, P<0.001), small LDL-C (23.0 nm, P<0.05), and very small LDL-C (16.7-20.7 nm, P<0.001), but a significantly lower large HDL-C (12.1 nm, P<0.001) concentrations. Combined variables of "small VLDL-C+small LDL-C+very small LDL-C-large HDL-C" differentiated the patient from the control group more clearly than single-subclass measurements or calculated traditional lipid markers. CONCLUSIONS: These results suggest the usefulness of multiple and simultaneous subclass analysis of proatherogenic and antiatherogenic lipoproteins and indicate that HPLC and its component analysis can be used for easy detection and evaluation of abnormal distribution of lipoprotein subclasses associated with CAD.

Adult↗
PubMed2006

Extensive genetic analysis of 10 candidate genes for hypertension in Japanese.

The identification of genes that contribute to essential hypertension has been hampered because of a lack of statistical power and problems with multiple testing. In the present study, we performed association analyses between the 161 single nucleotide polymorphisms of 10 candidate genes and hypertension in a Japanese population recruited from the Suita Study (n=3654). We found that 5 polymorphisms in the 3 genes (SLC9A2, UMOD, and ELN) were associated with hypertension status, and 4 of these 5 polymorphisms were also associated with blood pressure values with a classical criterion of P<0.05. However, when a Bonferroni correction for multiple testing was applied, none of the polymorphisms were associated with blood pressure levels. We also performed association analyses between these 5 polymorphisms and intermediate phenotypes corresponding with the functions of candidate genes, including the renin/aldosterone profile, plasma uric acid levels, and pulse wave velocity. The ELN 3'-untranslated region (-/A) polymorphism was found to significantly affect pulse wave velocity, an indicator of arterial stiffness. Associations of the ELN 3'-untranslated region (-/A) polymorphism with hypertension and pulse wave velocity were reconfirmed in another set of the study population. Thus, ELN seems to contribute to blood pressure regulation by affecting arterial stiffness in Japanese.

Adult↗
PubMed2006

Impact of blockade of histamine H2 receptors on chronic heart failure revealed by retrospective and prospective randomized studies.

OBJECTIVES: The goal of this work was to determine whether the blockade of histamine H2 receptors is beneficial for the pathophysiology of chronic heart failure (CHF). BACKGROUND: Because CHF is one of the major life-threatening diseases, we need to find a novel effective therapy. Intriguingly, our previous study, which predicts the involvement of histamine in CHF, suggests that we should test this hypothesis in patients with CHF. METHODS: We selected 159 patients who received famotidine among symptomatic CHF patients for the retrospective study. We blindly selected age- and gender-matched CHF patients receiving drugs for gastritis other than histamine H2 receptor blockers as a control group. For the prospective study, 50 symptomatic CHF patients were randomly divided into 2 groups. One group received famotidine of 30 mg/day for 6 months, and the other group received teprenone. RESULTS: In the retrospective study, famotidine of 20 to 40 mg decreased both left ventricular end-diastolic and end-systolic lengths (LVDd and LVDs, respectively) and the plasma B-type natriuretic peptide (BNP) levels (182 +/- 21 vs. 259 +/- 25 pg/ml, p < 0.05) with unaltered fractional shortening (FS). In a randomized, open-label study, compared with teprenone, famotidine of 30 mg prospectively decreased both New York Heart Association functional class (p < 0.05) and plasma BNP levels (183 +/- 26 pg/ml vs. 285 +/- 41 pg/ml, p < 0.05); this corresponded to decreasing both LVDd (57 +/- 2 mm vs. 64 +/- 2 mm, p < 0.05) and LVDs (47 +/- 2 mm vs. 55 +/- 2 mm, p < 0.05) with unaltered FS (15 +/- 1% vs. 17 +/- 1%). The frequency of readmission because of worsening of CHF was lower in the famotidine group (4% and 24%, p < 0.05). On the other hand, teprenone had no effects on CHF. CONCLUSIONS: Famotidine improved both cardiac symptoms and ventricular remodeling associated with CHF. Histamine H2 receptor blockers may have therapeutic benefits for CHF.

Aged↗
PubMed2006

Blockade of angiotensin II receptors reduces the expression of receptors for advanced glycation end products in human endothelial cells.

OBJECTIVE: Receptors for advanced glycation end products (RAGEs) play crucial roles in atherogenesis. Because tumor necrosis factor alpha (TNFalpha) is expressed and upregulates RAGE expression in atherosclerotic lesions, the TNFalpha-RAGE interaction might be involved in the inflammatory process of atherogenesis. On the other hand, an angiotensin II type-1 receptor blocker (ARB), widely used as an antihypertensive drug, has been reported to have also antiatherosclerotic effects. Thus we investigated whether an ARB exerts antiatherosclerotic effects via inhibiting the TNFalpha-RAGE interaction. METHODS AND RESULTS: Stimulation of human endothelial cells with candesartan as well as olmesartan decreased TNFalpha-induced RAGE expression in both mRNA and protein levels along with the decrease in the activity of nuclear factor kappaB and the expression of inflammatory mediators such as vascular cell adhesion molecule (VCAM)-1. Both candesartan and olmesartan inhibited the binding of nuclear factor kappaB to the RAGE gene promoter. Furthermore, gene silencing of RAGE by RNA interference decreased the expression of TNFalpha-induced VCAM-1 in both mRNA and protein levels. CONCLUSIONS: RAGE contributes at least partially to the TNFalpha-induced VCAM-1 expression in both mRNA and protein levels. Blockade of angiotensin II receptors might exert antiatherosclerotic effects via reducing TNFalpha-RAGE interaction.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2006

Blockade of histamine H2 receptors protects the heart against ischemia and reperfusion injury in dogs.

We have previously reported that histamine H(2) blockers may be cardioprotective in patients with chronic heart failure. Since both endogenous histamine and histamine H(2) receptors are present in heart tissue, we tested the hypothesis that the blockade of histamine H(2) receptors mediates protection against reversible or irreversible ischemia and reperfusion injury. In open-chest dogs, the left anterior descending coronary artery was occluded for 90 minutes, followed by reperfusion for 6 hours. Administration of famotidine and cimetidine from 10 minutes before occlusion until after 1 hour of reperfusion reduced infarct size (17.0 +/- 4.1% and 17.8 +/- 2.9% vs. 36.9 +/- 5.9% of the solvent group, respectively) Famotidine administration only during the reperfusion period for 1 hour also attenuated infarct size (22.5 +/- 3.5%). There were no differences in either area at risk or collateral flow among the groups. In another set of experiments, we decreased coronary perfusion pressure in dogs so that the coronary blood flow decreased to 50% of the non-ischemic level. In such conditions, we observed the increases in histamine release compared with non-ischemic conditions (0.04 +/- 0.03 to 0.28 +/- 0.13 ng/ml, p < 0.05). Famotidine improved anaerobic myocardial metabolism gauged by both lactate extraction ratio and myocardial oxygen consumption. We conclude that the blockade of histamine H(2) receptors mediates improvements in the anaerobic myocardial metabolism, and thus protects against ischemia and reperfusion injury.

Animals↗
PubMed2006

Haplotype of thrombomodulin gene associated with plasma thrombomodulin level and deep vein thrombosis in the Japanese population.

INTRODUCTION: Thrombomodulin (TM) is an essential cofactor in protein C activation by thrombin. Here, we evaluated the contribution of genetic variations in the TM gene to soluble TM (sTM) level and deep vein thrombosis (DVT) in Japanese. PATIENTS AND METHODS: We sequenced the TM putative promoter, exon, and 3'-untranslated region in DVT patients (n=118). Among 17 genetic variations we identified, two missense mutations (R385K, D468Y) and three common single nucleotide polymorphisms (-202G>A, 2487A>T, 2729A>C) were genotyped in a general population of 2247 subjects (1032 men and 1215 women) whose sTM levels were measured. We then compared the frequency of these mutations in DVT patients with that in the age, body mass index-adjusted population-based controls. RESULTS: We identified one neutral mutation (H381) and three missense mutations (R385K; n=2, A455V; n=53 heterozygous, n=14 homozygous, D468Y; n=2) of TM in the DVT patients. Age-adjusted mean values of sTM were lower in C-allele carriers of 2729A>C than in noncarriers in the Japanese general population (women: 16.7+/-0.3 U/ml vs. 17.9+/-0.2 U/ml, p<0.01, men: 19.4+/-0.3 U/ml vs. 20.4+/-0.3 U/ml, p=0.03). Additionally, the CC genotype of this mutation was more common in the male DVT patients than in the male individuals of the general population (odds ratio=2.76, 95% confidence interval=1.14-6.67; p=0.02). This mutation was in linkage disequilibrium (r-square>0.9) with A455V mutation. CONCLUSIONS: TM mutations, especially those with a haplotype consisting of 2729A>C and A455V missense mutation, affect sTM levels, and may be associated with DVT in Japanese.

3' Untranslated Regions↗
PubMed2006

The antagonism of aldosterone receptor prevents the development of hypertensive heart failure induced by chronic inhibition of nitric oxide synthesis in rats.

Aldosterone promotes cardiovascular inflammation and remodeling, both of which are characteristic changes in hypertensive and failing hearts. Since chronic inhibition of nitric oxide (NO) synthase with N(omega)-nitro-L-arginine methyl ester (L-NAME) induces systemic hypertension associated with cardiovascular inflammation and remodeling, we examined the potential role of aldosterone in this process using eplerenone, a selective aldosterone receptor antagonist. Ten-week-old male Wistar-Kyoto rats were randomly divided into 3 groups: the control group (no treatment), the L-NAME group (received L-NAME 1 g/L in drinking water), and the L-NAME+Eplerenone group (L-NAME plus eplerenone at 100 mg/kg/day). After 8 weeks of the treatment, the L-NAME group showed significantly higher systolic blood pressure than the control group (198 +/- 7 vs. 141 +/- 3 mmHg, P < 0.05). Eplerenone did not affect the increase in blood pressure caused by L-NAME (189 +/- 12 mmHg). Chronic inhibition of NO synthesis increased the plasma aldosterone concentration and CYP11B2 mRNA in adrenal glands. Cardiac inflammation and fibrosis were detected in the L-NAME group, while both changes were completely prevented by eplerenone. Cardiac hypertrophy was induced in L-NAME group, but was partially prevented by eplerenone. In the L-NAME group, left ventricular fractional shortening (LVFS: 27 +/- 2 vs. 38 +/- 1%) and E/A ratio (1.7 +/- 0.1 vs. 2.1 +/- 0.1) were significantly lower and LV end-diastolic pressure (LVEDP) was higher (4.9 +/- 0.6 vs. 13.9 +/- 0.5 mmHg) without LV enlargement, compared with those in the control group (P < 0.05). Eplerenone completely normalized LVFS (36 +/- 2%), E/A ratio (2.2 +/- 0.1), and LVEDP (6.2 +/- 0.7 mmHg). These results suggest that chronic inhibition of NO synthesis induces cardiac inflammation and dysfunction via an aldosterone receptor-dependent mechanism.

Actins↗
PubMed2006

Progression of severe atherosclerosis and increased arterial pulse pressure in the newly developed heritable mixed hyperlipidaemic rabbits.

We have recently segregated a new line of rabbit, named TGH, with severely high levels of plasma triglyceride and cholesterol. The aim of the present study was to investigate the progression of atherosclerosis and haemodynamic parameters in TGH rabbits. 2. Japanese white (JW) and TGH rabbits (24-27 months old) were anaesthetized with ketamine and xylazine. Plasma concentrations of triglyceride were 63.1 8.0 and 446.0 35.2 mg/dL in JW and TGH rabbits, respectively. Blood pressure was measured by a catheter implanted in the femoral artery. Histological examinations were performed using haematoxylin-eosin and elastica-Masson trichrome staining to detect atherosclerotic lesions. 3. The JW rabbits had no atherosclerotic lesions. In TGH rabbits, severe atherosclerotic lesions were observed throughout the aorta, especially in the aortic arch. Basal femoral arterial pressure was not significantly different between JW and TGH rabbits. However, the basal pulse pressure in TGH rabbits (48.3 4.5 mmHg) was significantly greater than that of JW rabbits (28.0 5.6 mmHg). Intravenous infusion of N(G)-nitro-L-arginine methyl ester (L-NAME; 26.9 mg/kg) increased the blood pressure of TGH and JW rabbits. There was no significant difference in the response to L-NAME between the two rabbit strains. 4. The present study shows that severe atherosclerotic changes develop in TGH rabbits and suggests that the hyperlipidaemia combined with hypercholesterolaemia and hypertriglyceridaemia is an important factor for promoting atherosclerosis in TGH rabbits. The greater pulse pressure in TGH rabbits may be due to the increased vascular stiffness with atherosclerosis. 5. This newly developed TGH rabbit line of heritable hypertriglyceridaemia with hypercholesterolaemia will become a useful animal model for studies on the role of hyperlipidaemia in the progression of atherosclerosis and in many atherosclerosis-related diseases.

Aging↗
PubMed2006

Increased endothelin-1 levels of BAL fluid in patients with pulmonary sarcoidosis.

OBJECTIVE AND BACKGROUND: Pulmonary fibrosis in sarcoidosis is a significant cause of morbidity and mortality. Various factors have been intensely studied to define the pathogenesis of lung fibrosis in sarcoidosis. Endothelin (ET) consists of three isoforms and is known for its potent vasoconstrictor properties. ET plays an important role in the fibroproliferative process of interstitial lung diseases. METHODS: To investigate the role of ET in the progression of pulmonary fibrosis in sarcoidosis, ET-1 and ET-3 concentrations were measured in BAL fluid (BALF) in 22 non-smoking patients with sarcoidosis and in control subjects (n = 12). Immunoreactivity of ET-1 was also evaluated in alveolar macrophages (AMs) from sarcoidosis patients. To assess the effects of ET in BALF on fibroblast proliferation, human foetal lung fibroblasts were cultured with sarcoidosis or control BALFs in the presence or absence of the ET-receptor antagonist TAK-044. RESULTS: ET-1 levels in sarcoidosis BALF were significantly higher than those in control, whereas ET-3 levels were not different between sarcoidosis and control. ET-1 levels were correlated with the number of AMs in BALF. ET-1-immunoreactivity was found mainly in AM of sarcoidosis BALF. Sarcoidosis BALF significantly stimulated fibroblast proliferation, compared with control BALF, and the fibroblast proliferation induced by sarcoidosis BALF was inhibited by TAK-044. CONCLUSIONS: Increased levels of ET-1 in AM could enhance fibrogenesis in pulmonary sarcoidosis.

Adult↗
PubMed2006

Assessment of genetic effects of polymorphisms in the MCP-1 gene on serum MCP-1 levels and myocardial infarction in Japanese.

BACKGROUND: Recently, the Framingham Heart Study reported that genetic variations in CCL2 influence serum levels of monocyte chemoattractant protein-1 (MCP-1) and the incidence of myocardial infarction (MI). The purpose of the present study was to investigate the possible involvement of CCL2 in the pathogenesis of atherosclerosis and MI in Japanese. METHODS AND RESULTS: Multiple regression analysis indicated that the MCP-1 levels were significantly influenced by various factors including age, body mass index, smoking, alcohol intake, high density lipoprotein-cholesterol, and systolic blood pressure. Moreover, the serum MCP-1 level was significantly correlated with intima - media thickness (p < 0.0001). However, this association disappeared when other clinical confounding factors were included in the analyses. Comprehensive analysis of common polymorphisms of CCL2 in a large community-based population and in subjects with MI found that the A(-2138)T polymorphism affected the serum MCP-1 level in a subgroup of subjects 65 years and older. However, no significant differences in the frequencies of any of the polymorphisms or haplotypes were found between subjects with and without MI. None of the polymorphisms in CCL2 affected carotid atherosclerosis. CONCLUSIONS: The serum MCP-1 level was a good surrogate marker of atherosclerosis in the present study population. Although genetic variations in CCL2 may have some influence on MCP-1 production, their influence does not seem to contribute appreciably to atherosclerosis in Japanese. The present results did not support the recently published findings from the Framingham Heart Study. The discrepancy between the 2 studies may be related to differences in confounding factors that contribute to MCP-1 levels and in the haplotype structure of the 2 populations.

Aged↗
PubMed2006

Genetic variations of HSD11B2 in hypertensive patients and in the general population, six rare missense/frameshift mutations.

Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, HSD11B2, cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, defective HSD11B2 enzyme activity results in overstimulation of the mineralocorticoid receptor (MR) by cortisol, causing sodium retention, hypokalemia, and salt-dependent hypertension. Here, we have studied whether genetic variations in HDS11B2 are implicated in essential hypertension in Japanese hypertensives and the general population. By sequencing the entire coding region and the promoter region of HDS11B2 in 953 Japanese hypertensives, we identified five missense mutations in 11 patients (L14F, n = 5; R74H, n = 1; R147H, n = 3; T156I, n = 1; R335H, n = 1) and one novel frameshift mutation (4884Gdel, n = 1) in a heterozygous state, in addition to 19 genetic variations. All genetic variations identified were rare, with minor allele frequencies less than 0.005. Four of 12 patients with the missense/frameshift mutations showed renal failure. Four missense mutations, L14F, R74H, R147H, and R335H, were successfully genotyped in the general population, with a sample size of 3,655 individuals (2,175 normotensives and 1,480 hypertensives). Mutations L14F, R74H, R147H, and R335H were identified in hypertensives (n = 6, 8, 3, and 0, respectively) and normotensives (n = 8, 12, 5, and 0, respectively) with a similar frequency, suggesting that these missense mutations may not strongly affect the etiology of essential hypertension. Since the allele frequency of all of the genetic variations identified in this study was rare, an association study was not conducted. Taken together, our results indicate that missense mutations in HSD11B2 do not substantially contribute to essential hypertension in Japanese.

11-beta-Hydroxysteroid Dehydrogenase Type 2↗
PubMed2006

Association of sixty-one non-synonymous polymorphisms in forty-one hypertension candidate genes with blood pressure variation and hypertension.

We previously selected a group of hypertension candidate genes by a key word search using the OMIM database of NCBI and validated 525 coding single nucleotide polymorphisms (SNPs) in 179 hypertension candidate genes by DNA sequencing in a Japanese population. In the present study, we examined the association between 61 non-synonymous SNPs and blood pressure variations and hypertension. We used DNA samples taken from 1,880 subjects in the Suita study, a population-based study using randomly selected subjects. Analyses of covariance adjusting for age, body mass index, hyperlipidemia, diabetes, smoking, drinking, and antihypertensive medication revealed that 17 polymorphisms in 16 genes (APOB, CAST, CLCNKB, CTNS, GHR, GYS1, HF1, IKBKAP, KCNJ11, LIPC, LPL, P2RY2, PON2, SLC4A1, TRH, VWF) were significantly associated with blood pressure variations. Multivariate logistic regression analysis with adjustment for the same factors revealed that 11 polymorphisms in 11 genes (CAST, CTLA4, F5, GC, GHR, LIPC, PLA2G7, SLC4A1, SLCI8A1, TRH, VWF) showed significant associations with hypertension. Five polymorphisms in five genes, CAST(calpastatin), LIPC (hepatic lipase), SLC4A1 (band 3 anion transporter), TRH (thyrotropin-releasing hormone), and VWF (von Willebrand factor), were significantly associated with both blood pressure variation and hypertension. Thus, our study suggests that these five genes were susceptibility genes for essential hypertension in this Japanese population.

Aged↗