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Biomedical subjects

Takeshi Horio

Publications and source records attributed to Takeshi Horio.

At least 19 recordsLinked to original sources

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↗

Reverse white-coat effect as an independent risk for microalbuminuria in treated hypertensive patients.

BACKGROUND: The influence of the converse phenomenon of white-coat hypertension called 'reverse white-coat hypertension' or 'masked hypertension' on hypertensive target organ damage has not been fully elucidated. The present study assessed the hypothesis that this phenomenon may specifically associate with microalbuminuria, a marker of early renal damage, in treated hypertension. METHODS: A total of 267 treated essential hypertensive patients (133 men and 134 women; mean age, 66 years) without renal insufficiency or macroalbuminuria were enrolled in this study. Patients were classified into three groups by the difference between office and day-time ambulatory systolic blood pressure (BP) levels; i.e. subjects with white-coat effect (W group: office--day-time systolic BP > or =20 mmHg, n = 48), with reverse white-coat effect (R group: office - day-time systolic BP < - 10 mmHg, n = 43) and without white-coat or reverse white-coat effect (N group: -10 mmHg < or = office--day-time systolic BP <20 mmHg, n = 176). The urinary albumin (U-Alb) level was measured as the albumin to creatinine excretion ratio in the urine. Microalbuminuria was defined as U-Alb of > or =30 and <300 mg/g Cr. RESULTS: R group had a well-controlled office BP (130/77 mmHg), but their day-time BP (148/87 mmHg) was elevated compared with the other two groups. The levels of U-Alb excretion in N group, W group and R group were 12.3 (8.4, 25.6), 16.0 (10.5, 31.7) and 24.3 (10.2, 79.7) mg/g Cr [median (interquartile range)], respectively. Both U-Alb level and prevalence of microalbuminuria were significantly greater in R group than in N group. Multivariate analyses revealed that the presence of reverse white-coat effect, but not white-coat effect, was a significant predictor for microalbuminuria, independent of various clinical variables including ambulatory BP levels (odds ratio 2.63 vs N group, P = 0.02). CONCLUSION: These findings suggest that the presence of reverse white-coat effect may be an independent risk for early renal damage in treated hypertensive patients.

Adult↗

Adiponectin and renal function, and implication as a risk of cardiovascular disease.

The relation among adiponectin, renal function, and incident cardiovascular disease (CVD) in patients with different degrees of renal dysfunction was investigated. In total, 150 subjects were included in this study and followed prospectively for a mean of 32 months. At baseline, median adiponectin levels for chronic kidney disease (CKD) stages 1, 2, 3, 4 and 5, as estimated by creatinine clearance (> or =90, 60 to 90, 30 to 60, <30 ml/min), were 3.06, 4.04, 6.43, and 11.9 microg/ml, respectively (p for trend <0.01), and a significant association between adiponectin and CKD stages was also confirmed in multivariate regression analysis (F = 6.2, p <0.001). During follow-up, 31 subjects developed CVD, including myocardial infarction, angina pectoris, stroke, and transient ischemic attack. Gender-specific median values of adiponectin were used to separate the higher group from the lower group, and the Kaplan-Meier curve showed a significantly lower event-free survival rate in the lower adiponectin group (<4.39 microg/ml in men, <6.84 microg/ml in women, chi-square 4.88, p <0.03). The risk factor-adjusted Cox regression showed that an increase in adiponectin per 1 microg/ml was associated with a decrease in the risk of CVD to 0.86 (95% confidence interval 0.75 to 0.96, p = 0.004). In the subgroup with previous ischemic heart disease (IHD; n = 65), a significantly lower event-free survival rate of IHD was also observed in the lower adiponectin group (<4.45 microg/ml in men, <4.49 microg/ml in women, chi-square 3.96, p <0.05). The relative distribution of adiponectin isoforms was examined in patients with severe CKD, and the percentage of the high-molecular-weight form in patients with IHD during follow-up (n = 3) was significantly smaller than that in those without IHD (n = 4, p <0.02). In conclusion, renal function is a significant regulator of adiponectin when categorized by CKD stage, whereas hypoadiponectinemia is a predictor of CVD, including recurrent IHD.

Adiponectin↗

Renal function in patients with abdominal aortic aneurysm. Comparison with hypertensive patients.

AIMS: Renal dysfunction occurs occasionally after the repair of abdominal aortic aneurysm (AAA), and preoperative renal function is considered as one of the potential causes. The present study was designed to evaluate and compare renal function and risk factors of AAA patients with those of hypertensive patients. METHODS: We prospectively examined 95 patients with AAA and 72 patients with essential hypertension (HT) without other cardiovascular diseases (CVD). Renal function, urinary albumin excretion (UAE) and renal scintigraphy were compared. Kidney size was calculated using ultrasonography. RESULTS: Serum creatinine and creatinine clearance in AAA patients was worse than in HT patients. Smoking status was more apparent in AAA patients. Renal artery stenosis occurred in 8 patients with AAA. Renal scintigraphy showed normal function in 19%, hypofunction in 69% and severe dysfunction in 12% of the AAA patients, and normal function in 42% and hypofunction in 58% of the HT patients (p < 0.0001). Multivariate linear regression analysis showed that renal function was related to age, UAE, CVD, smoking status and kidney size for all patients, UAE, CVD, smoking status and kidney size for AAA patients, and age and kidney size for HT patients. CONCLUSION: Renal function of AAA patients was worse than HT patients without other CVD. The risk factors for renal dysfunction were different between AAA and HT patients. These preoperative conditions may relate to the postoperative renal dysfunction seen in AAA patients.

Aged↗

Masked hypertension and target organ damage in treated hypertensive patients.

BACKGROUND: Recent studies have shown that an elevated ambulatory or home blood pressure (BP) in the absence of office BP-a phenomenon called masked hypertension-is associated with poor cardiovascular prognosis. However, it remains to be elucidated how masked hypertension modifies target organ damage in treated hypertensive patients. METHODS: A total of 332 outpatients with chronically treated essential hypertension were enrolled in the present study. Patients were classified into four groups according to office (<140/90 or >or=140/90 mm Hg) and daytime ambulatory (<135/85 or >or=135/85 mm Hg) BP levels; ie, controlled hypertension (low office and ambulatory BP), white-coat hypertension (high office but low ambulatory BP), masked hypertension (low office but high ambulatory BP), and sustained hypertension (high office and ambulatory BP). Left ventricular mass index, carotid maximal intima-media thickness, and urinary albumin levels were determined in all subjects. RESULTS: Of the patients, 51 (15%), 65 (20%), 74 (22%), and 142 (43%) were identified as having controlled hypertension, white-coat hypertension, masked hypertension, and sustained hypertension, respectively. Left ventricular mass index, maximal intima-media thickness, and urinary albumin level in masked hypertension were significantly higher than in controlled hypertension and white-coat hypertension, and were similar to those in sustained hypertension. Multivariate regression analyses revealed that the presence of masked hypertension was one of the independent determinants of left ventricular hypertrophy, carotid atherosclerosis, and albuminuria. CONCLUSIONS: Our findings indicate that masked hypertension is associated with advanced target organ damage in treated hypertensive patients, comparable to that in cases of sustained hypertension.

Aged↗

Adiponectin and inflammatory markers in peripheral arterial occlusive disease.

This study was designed to examine the plasma levels of adiponectin as well as markers of inflammation and endothelial function in peripheral arterial occlusive disease (PAOD), and to investigate the pathophysiological significance of adiponectin in this disease. Eighty-eight subjects with (n=40) and without PAOD (n=48) were enrolled. Multiple regression analysis including age, sex, body mass index, hypertension, diabetes, triglycerides, high-density lipoprotein cholesterol, creatinine, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cellular adhesion molecules-1 (sVCAM-1), von Willebrand factor, and high-sensitive C reactive protein (Hs-CRP) showed that adiponectin concentration was significantly lower in PAOD subjects (PAOD: 7.9+/-0.7 microg/mL versus without PAOD: 9.5+/-0.6 microg/mL, F=4.94, p<0.03). Furthermore, concentrations of adiponectin (F=8.5, p<0.01) as well as sICAM-1 (F=5.8, p<0.02), sVCAM-1 (F=5.9, p<0.02), and Hs-CRP (F=3.8, p=0.05) were independently associated with ankle-brachial index. In 27 subjects (10 with PAOD and 17 without PAOD), adiponectin levels in the femoral artery and saphenous vein were measured. A significant step-up of adiponectin from the artery to the vein was observed in subjects without PAOD (+13.0%, p<0.01), but not in subjects with PAOD (+0.4%, NS). Plasma adiponectin as well as Hs-CRP were followed before and after percutaneous transluminal angioplasty (PTA) in eight patients. Adiponectin showed a tendency to decrease after PTA (day 6, -30.6%), although Hs-CRP significantly increased. Adiponectin is decreased in patients with PAOD in proportion to the severity of the disease. Adiponectin concentration could be a marker of the existence of atherosclerosis, and measurement of its concentration may be helpful in assessment of the progress of atherosclerosis.

Adiponectin↗

Ultraviolet B radiation suppresses Langerhans cell migration in the dermis by down-regulation of alpha4 integrin.

BACKGROUND/PURPOSE: Ultraviolet B (UVB) radiation affects the migration and function of epidermal Langerhans cells (LC) and causes immunosuppression of contact hypersensitivity. It is known that LC leaves the epidermis after exposure to UVB. To know the behavior of LC in the dermis after UVB radiation, we studied the effect of UVB radiation on the expression of integrin families on freshly isolated or cultured murine LC. We also examined whether UVB radiation affects the migration of LC to secondary lymphoid tissue chemokine (SLC/6Ckine). METHODS: Integrin expressions of murine LC cultured in epidermal cell suspension were analyzed using flowcytometry. We used murine LC sorted flowcytometrically for binding assay to extracellular matrix and for migration assay to chemokine. Skin explant assay and immnohistochemical staining for 'cords formation' were performed as previously described. RESULTS: Twenty and 40 mJ/cm2 of UVB radiation down-regulated the expression of alpha4 integrin on 24 h-cultured LC, but not that of alpha6, beta1, or beta4 integrin. The number of cultured LC adhered to fibronectin, a ligand for alpha4 integrin, was decreased after UVB irradiation, while that to laminin, a ligand for alpha6 integrin, was not influenced. UVB radiation reduced the number of migrating LC to SLC. Furthermore, skin sheet explant experiments showed that UVB radiation inhibited the 'cords' formation in dermal vessels of the 48 h-cultured skin. CONCLUSIONS: These data suggest that UVB radiation may suppress the migration of LC from the dermis to lymphatic vessels. UVB radiation may downregulate the adherence of LC to dermal fibronectin and migration to SLC, and consequently suppress the migration of LC from the UVB-irradiated dermis to lymphatics.

Animals↗

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↗

[Pathophysiological role of cytokines in heart failure].

Plasma and myocardial levels of proinflammatory cytokines such as tumor necrosis factor(TNF)-alpha, interleukin 1beta, and interleukin 6 are elevated in patients with heart failure. Not only viral infection but also cardiac overload, ischemia, and neuro-humoral factors stimulate systemic and myocardial production of these cytokines. Administration of proinflammatory cytokines directly depresses myocardial contractility in vitro and in vivo. In addition, TNF and interleukin induce myocardial apoptosis and promote cardiac hypertrophy and fibrosis, suggesting that these cytokines are involved in the progression of cardiac remodeling. Vasoactive peptides such as endothelin and adrenomedullin also have cytokine-like functions in the heart, acting as autocrine and paracrine factors. Thus, proinflammatory cytokines and these peptides play important roles in the pathogenesis and pathophysiology of heart failure.

Animals↗

Uric acid, left ventricular mass index, and risk of cardiovascular disease in essential hypertension.

Elevated serum uric acid (UA) is frequently encountered in individuals with hypertension, but whether the relationship between UA and cardiovascular events is circumstantial or causal remains to be answered. We examined the association between serum UA and left ventricular mass index (LVMI) and investigated prospectively whether the combination of UA and LVMI can predict the incidence of cardiovascular disease (CVD) in asymptomatic subjects with essential hypertension. A total of 619 subjects (mean age, 61 years; 52% female) free of prior CVD were included in this study. A significant association between UA and LVMI was also confirmed in multiple regression analysis (male: F=4.29, P<0.04; female: F=4.24, P<0.05). During follow-up (mean, 34 months), 28 subjects (14 female) developed CVD including myocardial infarction, angina pectoris, congestive heart failure, cerebral infarction, and transient cerebral ischemia. Sex-specific median values were used to separate the higher group from the lower group of UA and LVMI. Kaplan-Meier curves showed a significantly poorer survival rate in the group with higher UA and LVMI (LVMI, male: >126.9, female: >112.0 g/m2; UA, male: >374.7, female: >303.3 micromol/L; log-rank chi2=13.18; P<0.01). Multivariate Cox regression analysis showed that the combination of higher UA and LVMI was an independent predictor for CVD events (hazard ratio, 2.38; P<0.03). Our findings demonstrate that UA is independently associated with LVMI and suggest that the combination of hyperuricemia combined with left ventricular hypertrophy is an independent and powerful predictor for CVD. The association between UA and CVD events may be introduced in part because of a direct association of UA with LVMI.

Cardiovascular Diseases↗

Prostacyclin agonist with thromboxane synthase inhibitory activity (ONO-1301) attenuates bleomycin-induced pulmonary fibrosis in mice.

The balance between prostacyclin and thromboxane A2 (TXA2) plays an important role in pulmonary homeostasis. However, little information is available regarding the therapeutic potency of these prostanoids for pulmonary fibrosis. We have recently developed ONO-1301, a novel long-acting prostacyclin agonist with thromboxane synthase inhibitory activity. Thus we investigated whether repeated administration of ONO-1301 attenuates bleomycin-induced pulmonary fibrosis in mice. After intratracheal injection of bleomycin or saline, mice were randomized to receive repeated subcutaneous administration of ONO-1301 or vehicle. Bronchoalveolar lavage (BAL) and histological analyses were performed at 3, 7, and 14 days after bleomycin injection. In vitro studies using mouse lung fibroblasts were also performed. ONO-1301 significantly attenuated the development of bleomycin-induced pulmonary fibrosis, as indicated by significant decreases in Ashcroft score and lung hydroxyproline content. ONO-1301 significantly reduced total cell count, neutrophil count, and total protein level in BAL fluid in association with a marked reduction of TXB2. A single administration of ONO-1301 significantly increased plasma cAMP level for >2 h. In vitro, ONO-1301 and a cAMP analog dose-dependently reduced cell proliferation in mouse lung fibroblasts. The reduction in cell proliferation by ONO-1301 was attenuated by a protein kinase A (PKA) inhibitor. Furthermore, bleomycin mice treated with ONO-1301 had a significantly higher survival rate than those given vehicle. These results suggest that repeated administration of ONO-1301 attenuates the development of bleomycin-induced pulmonary fibrosis and improves survival in bleomycin mice, at least in part by inhibition of TXA2 synthesis and activation of the cAMP/PKA pathway.

Animals↗

DNA damage initiates photobiologic reactions in the skin.

Ultraviolet (UV) radiation can induce acute and chronic photobiologic reactions in the absence of exogenous chromophores. Nuclear DNA is a major chromophore to initiate UV-induced physiologic reactions. The XPA-gene deficient mouse, an animal model of xeroderma pigmentosum, develops increased photobiologic reactions including acute inflammation, immunosuppression and skin cancers, because of the defect in the excision repair of UV-induced DNA lesions.

Animals↗

Effects of UVB on fascin expression in dendritic cells and Langerhans cells.

BACKGROUND: Fascin is an actin-binding protein that regulates the rearrangement of cytoskeletal elements and their interactions with the cell membrane. Previous studies have indicated that fascin expression is enhanced in DC upon maturation and plays a critical role in T cell activation. Ultraviolet irradiation exerts immunosuppressive effects. OBJECTIVE: We examined the effects of UVB irradiation on the interaction of DC/LC with T cells through fascin. METHOD: Murine bone marrow-derived DC (BM-DC) were induced by recombinant murine GM-CSF and LPS, and UVB irradiation was applied prior to supplementation with LPS. I-A(+) cells (Langerhans cells (LC)) in the epidermal cell suspensions were exposed to UVB irradiation at the beginning of the 24-h culture. BM-DC and LC were analysed by immunohistochemical staining and flow cytometric analyses. To evaluate the effects of UVB irradiation on DC-T cell binding, we examined the clustering of BM-DC with allogeneic CD4(+) T cells under a confocal microscope. RESULTS: Fascin expression in BM-DC and LC was decreased by UVB irradiation. Furthermore, UVB irradiation reduced the ability of BM-DC to cluster with allogeneic CD4(+) T cells. Polarization of fascin and filamentous actin (F-actin) at the point of contact of BM-DC with T cells was also disturbed by UVB irradiation. CONCLUSION: These results suggest that the suppression of fascin expression by UVB irradiation down-regulates the rearrangement of the cytoskeleton and, thereby, antigen presentation in DC/LC.

Animals↗

Insertion/deletion polymorphism in clusterin gene influences serum lipid levels and carotid intima-media thickness in hypertensive Japanese females.

Clusterin has been implicated in lipid metabolism and atherogenesis, however, the influence of genetic variation has not been examined in Japanese. In this study, we identified 11 single nucleotide polymorphisms (SNPs) of clusterin gene by direct sequencing. Among them, one promoter SNP (-4453T>G), one missense SNP (4183G>A), and 2 common SNPs (5608T>C and 6316delT) were genotyped in 525 asymptomatic hypertensives not treated with lipid lowering agents. -4453T>G, 4183G>A, and 5608T>C showed no correlation with the clinical characteristics, however, in the 6316delT, an insertion (I)/deletion (D) polymorphism, D/D subjects had significantly higher levels of total cholesterol and low-density lipoprotein (LDL)-cholesterol than I/I subjects in females but not in males. Female subjects with the D allele (D/D+I/D) had greater intima-media thickness of the carotid artery than I/I subjects. In a multiple logistic regression analysis, the D allele of 6316delT was detected as an independent predictor for the plaque prevalence. In conclusion, the clusterin gene polymorphism may contribute to the serum lipid levels and the progression of carotid atherosclerosis in hypertensive Japanese females.

Aged↗

Calcineurin-nuclear factor of activated T cells pathway-dependent cardiac remodeling in mice deficient in guanylyl cyclase A, a receptor for atrial and brain natriuretic peptides.

BACKGROUND: Although disruption of guanylyl cyclase (GC) A, a natriuretic peptide receptor, induces cardiac hypertrophy and fibrosis, the molecular mechanism underlying these effects are not well understood. In this study, we examined the role of calcineurin, a calcium-dependent phosphatase, in cardiac remodeling in GCA-knockout (GCA-KO) mice. METHODS AND RESULTS: At 14 weeks of age, calcineurin activity, nuclear translocation of nuclear factor of activated T cells c3 (NFATc3), and modulatory calcineurin-interacting protein 1 (MCIP1) gene expressions were increased in the hearts of GCA-KO mice compared with wild-type (WT) mice. Blockade of calcineurin activation by FK506 (6 mg/kg body weight administered subcutaneously once a day from 10 to 14 weeks of age) significantly decreased the heart-to-body weight ratio, cardiomyocyte size, and collagen volume fraction in GCA-KO mice, whereas FK506 did not affect these parameters in WT mice. Overexpression of atrial and brain natriuretic peptides, collagen, and fibronectin mRNAs in GCA-KO mice was also attenuated by FK506. Electrophoretic mobility shift assays demonstrated that GATA4 DNA-binding activity was increased in GCA-KO mice, and this increase was inhibited by calcineurin blockade. In neonatal cultured cardiac myocytes, inhibition of GCA by HS142-1 (100 microg/mL) increased basal and phenylephrine (10(-6) mol/L)-stimulated calcineurin activity, nuclear translocation of NFATc3, and MCIP1 mRNA expression. In contrast, activation of GCA by atrial natriuretic peptide (10(-6) mol/L) inhibited phenylephrine (10(-6) mol/L)-stimulated nuclear translocation of NFATc3. CONCLUSIONS: These results suggest that activation of cardiac GCA by locally secreted natriuretic peptides protects the heart from excessive cardiac remodeling by inhibiting the calcineurin-NFAT pathway.

Animals↗

Association of hypoadiponectinemia with smoking habit in men.

Adiponectin is emerging as an important molecule in obesity, the metabolic syndrome, and cardiovascular disease. On the other hand, smoking habit is well known to be related to cardiovascular disease and hypertension. To examine the association between adiponectin concentration and smoking habit, we performed an epidemiological survey and an acute exposure test in humans and an experiment in adipocytes to elucidate the mechanism underlying the association between adiponectin and smoking. In the epidemiological study, we enrolled a total of 331 male subjects to examine chronic smoking exposure. Plasma adiponectin was significantly lower (P=0.01) in current smokers (5.3+/-0.3 microg/mL) than in never-smokers (6.5+/-0.4 microg/mL). A significant association between smoking and low adiponectin level was also confirmed in multiple regression analysis including age, body mass index, hypertension, diabetes, hyperlipidemia, and creatinine clearance (never-smokers 6.5+/-0.4 microg/mL; past smokers 5.6+/-0.3 microg/mL; current smokers 5.2+/-0.4 microg/mL; F=4.52; P=0.01). To examine the acute effect of smoking on adiponectin concentration for 12 hours, we measured plasma adiponectin level in 5 male never-smokers before smoking and 3, 6, and 12 hours after smoking, with the result that adiponectin showed a significant decrease after smoking (12 hours; -14.5+/-0.6%; P<0.01). In cultured mouse 3T3-L1 adipocytes, H2O2 and nicotine reduced the mRNA expression and secretion of adiponectin in a dose-dependent manner. Smoking habit is associated with adiponectin concentration in men, and its suppressive effect is mediated in part through direct inhibition of smoking on adiponectin expression in adipocytes.

3T3 Cells↗

Chronic administration of adrenomedullin attenuates the hypertension and increases renal nitric oxide synthase in Dahl salt-sensitive rats.

Adrenomedullin reduces systemic blood pressure and increases urinary sodium excretion partly through the release of nitric oxide. We hypothesized that chronic adrenomedullin infusion ameliorates salt-sensitive hypertension and increases the expression of renal nitric oxide synthase (NOS) in Dahl salt-sensitive (DS) rats, because the reduced renal NOS expression promotes salt sensitivity. DS rats and Dahl salt-resistant (DR) rats were fed a high sodium diet (8.0% NaCl) for 3 weeks. The high sodium diet resulted in an increase in blood pressure and a reduction of urinary sodium excretion in association with increased renal adrenomedullin concentrations and decreased expression of renal neuronal NOS (nNOS) and renal medullary endothelial NOS (eNOS) in DS rats compared with DR rats. Chronic adrenomedullin infusion partly inhibited the increase of blood pressure and proteinuria in association with a restoration of renal nNOS and medullary eNOS expression in DS rats under the high sodium diet. The immunohistochemical analysis revealed that the restored renal nNOS expression induced by chronic adrenomedullin infusion may reflect the restoration of nNOS expression in the macula densa and inner medullary collecting duct. These results suggest that adrenomedullin infusion has beneficial effects on this hypertension probably in part through restored renal NOS expression in DS rats.

Adrenomedullin↗