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Biomedical subjects

Shinji Kihara

Publications and source records attributed to Shinji Kihara.

At least 37 records · Page 2Linked to original sources
PubMed2004

Adiponectin down-regulates acyl-coenzyme A:cholesterol acyltransferase-1 in cultured human monocyte-derived macrophages.

Acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT-1) catalyzes the formation of cholesteryl esters (CE) and plays a significant role in formation of macrophage-derived foam cells in atherosclerotic lesions. Adiponectin was reported to play an anti-atherogenic role by inhibiting class A scavenger receptor (SR-A) expression in human macrophages. To further clarify its additional property, we examined its effect on ACAT-1 expression using human macrophages. Immunoblot analyses revealed a significant reduction of ACAT-1 protein by a low concentration (1 microg/ml) of adiponectin. The ACAT activity was also decreased in parallel by adiponectin. Northern blot analyses revealed that all four ACAT-1 mRNA transcripts (2.8, 3.6, 4.3, and 7.0 kb) were decreased almost equally by adiponectin. Furthermore, acetyl-LDL-induced CE-accumulation in these macrophages was reduced significantly by this adipocytokine. These results demonstrate the inhibitory effect of adiponectin on ACAT-1 expression, suggesting that adiponectin may play an anti-atherogenic role by down-regulating the expression of ACAT-1 as well as SR-A in human macrophages.

Adiponectin↗
PubMed2004

Hypoadiponectinemia is an independent risk factor for hypertension.

Adiponectin is one of the key molecules in the metabolic syndrome, and its concentration is decreased in obesity, type-2 diabetes, and coronary artery disease. Genetic investigation has revealed that 2 polymorphisms (I164T and G276T) are related to adiponectin concentration and diabetes. To examine whether adiponectin affects hypertension genetically or biologically, we performed a case-control study. A total of 446 diagnosed cases of hypertension (HT) in men and 312 normotensive (NT) men were enrolled in this study. Plasma adiponectin concentration was measured using an enzyme-linked immunosorbent assay system. Single nucleotide polymorphisms were determined by TaqMan polymerase chain reaction method. After adjustment for confounding factors, adiponectin concentration was significantly lower in HT (HT: 5.2+/-0.2 microg/mL; NT: 6.1+/-0.2 microg/mL; P<0.001). Furthermore, multiple regression analysis indicated that hypoadiponectinemia was an independent risk factor for hypertension (P<0.001). Blood pressure was inversely associated with adiponectin concentration in normotensives regardless of insulin resistance. In subjects carrying the TC genotype of the I164T polymorphism, adiponectin concentration was significantly lower (TC: 2.6+/-0.9 microg/mL; TT: 5.5+/-0.1 microg/mL; P<0.01), and most of them had hypertension. In contrast, the G276T polymorphism was not associated with adiponectin concentration or hypertension. In conclusion, hypoadiponectinemia is a marker for predisposition to hypertension in men.

Adiponectin↗
PubMed2004

Adiponectin stimulates angiogenesis in response to tissue ischemia through stimulation of amp-activated protein kinase signaling.

Obesity is a risk factor for the development of cardiovascular diseases that are associated with impaired angiogenesis. Adiponectin is an adipocyte-specific adipocytokine with anti-atherogenic and anti-diabetic properties, and its plasma levels are reduced in association with obesity-linked diseases. Here, we investigated whether adiponectin regulates angiogenesis in response to tissue ischemia using adiponectin knock-out (KO) mice. Angiogenic repair of ischemic hind limbs was impaired in adiponectin-KO mice compared with wild-type (WT) mice as evaluated by laser Doppler flow method and capillary density analyses. Adenovirus-mediated supplement of adiponectin accelerated angiogenic repair in both adiponectin-KO and WT mice. Intramuscular injection of an adenovirus encoding dominant-negative AMP-activated kinase diminished the improvement in limb perfusion seen in WT mice and abolished the adiponectin-induced enhancement of perfusion. These data indicate that adiponectin can function to stimulate angiogenesis in response to ischemic stress by promoting AMP-activated kinase signaling. Therefore, adiponectin may be useful in the treatment for obesity-related vascular deficiency diseases.

AMP-Activated Protein Kinases↗
PubMed2004

Adiponectin specifically increased tissue inhibitor of metalloproteinase-1 through interleukin-10 expression in human macrophages.

BACKGROUND: Vascular inflammation and subsequent matrix degradation play an important role in the development of atherosclerosis. We previously reported that adiponectin, an adipose-specific plasma protein, accumulated to the injured artery and attenuated vascular inflammatory response. Clinically, high plasma adiponectin level was associated with low cardiovascular event rate in patients with chronic renal failure. The present study was designed to elucidate the effects of adiponectin on matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in human monocyte-derived macrophages. METHODS AND RESULTS: Human monocyte-derived macrophages were incubated with the physiological concentrations of human recombinant adiponectin for the time indicated. Adiponectin treatment dose-dependently increased TIMP-1 mRNA levels without affecting MMP-9 mRNA levels. Adiponectin also augmented TIMP-1 secretion into the media, whereas MMP-9 secretion and activity were unchanged. Time course experiments indicated that TIMP-1 mRNA levels started to increase at 24 hours of adiponectin treatment and were significantly elevated at 48 hours. Adiponectin significantly increased interleukin-10 (IL-10) mRNA expression at the transcriptional level within 6 hours and significantly increased IL-10 protein secretion within 24 hours. Cotreatment of adiponectin with anti-IL-10 monoclonal antibody completely abolished adiponectin-induced TIMP-1 mRNA expression. CONCLUSIONS: Adiponectin selectively increased TIMP-1 expression in human monocyte-derived macrophages through IL-10 induction. This study identified, for the first time, the adiponectin/IL-10 interaction against vascular inflammation.

Adiponectin↗
PubMed2004

Adiponectin I164T mutation is associated with the metabolic syndrome and coronary artery disease.

OBJECTIVES: This study examined the association of mutations in adiponectin gene with the prevalence of coronary artery disease (CAD). BACKGROUND: Coronary artery disease is a major cause of mortality in the industrial countries. Adiponectin gene locus, chromosome 3q27, is the candidate site for CAD. We have reported that adiponectin has antiatherogenic and antidiabetic properties, and that the plasma levels negatively correlated with body mass index (BMI) are significantly low in patients with CAD or type 2 diabetes. METHODS: The study subjects were 383 consecutive patients with angiographically confirmed CAD and 368 non-CAD subjects adjusted for age and BMI in the Japanese population. Single nucleotide polymorphisms (SNPs) in the adiponectin gene were determined by Taqman polymerase chain reaction (PCR) method or a PCR-based assay for the analysis of restriction fragment length polymorphism. The plasma adiponectin concentration was measured by enzyme-linked immunosorbent assay. RESULTS: Among SNPs, the frequency of I164T mutation was significantly higher in CAD subjects (2.9%) than in the control (0.8%, p < 0.05). The plasma adiponectin levels in subjects carrying the I164T mutation were significantly lower than in those without the mutation, and were independent of BMI. In contrast, SNP94 and SNP276, which are reported to be associated with an increased risk of type 2 diabetes, were associated neither with CAD prevalence nor with plasma adiponectin level. Subjects with I164T mutation exhibited a clinical phenotype of the metabolic syndrome. CONCLUSIONS: The I164T mutation in the adiponectin gene was a common genetic background associated with the metabolic syndrome and CAD in the Japanese population.

Adiponectin↗
PubMed2004

Adiponectin-induced antiangiogenesis and antitumor activity involve caspase-mediated endothelial cell apoptosis.

Obesity is a risk factor for the development of many severe human diseases such as cardiovascular disorders, diabetes, and cancer, which are tightly linked to angiogenesis. The adipose tissue produces several growth factors/hormones including leptin, tumor necrosis factor alpha, and adiponectin. It has been found that adiponectin levels are reduced in obesity. Here, we report a unique function of adiponectin as a negative regulator of angiogenesis. In vitro, adiponectin potently inhibits endothelial cell proliferation and migration. In the chick chorioallantoic membrane and the mouse corneal angiogenesis assays, adiponectin remarkably prevents new blood vessel growth. Further, we demonstrate that the antiendothelial mechanisms involve activation of caspase-mediated endothelial cell apoptosis. Adiponectin induces a cascade activation of caspases-8, -9, and -3, which leads to cell death. In a mouse tumor model, adiponectin significantly inhibits primary tumor growth. Impaired tumor growth is associated with decreased neovascularization, leading to significantly increased tumor cell apoptosis. These data demonstrate induction of endothelial apoptosis as an unique mechanism of adiponectin-induced antiangiogenesis. Adiponectin, as a direct endogenous angiogenesis inhibitor, may have therapeutic implications in the treatment of angiogenesis-dependent diseases.

Adiponectin↗
PubMed2004

Selective suppression of endothelial cell apoptosis by the high molecular weight form of adiponectin.

Adiponectin is an adipocyte-derived, antiatherogenic protein that is present in serum as three isoforms. Total adiponectin levels are decreased in obese or diabetic humans or animal models. This study was designed to elucidate the relative isoform distribution of adiponectin in human disease states and identify the active form of adiponectin toward vascular endothelial cells. The percentage of high molecular weight form (HMW) per total adiponectin was significantly lower in patients with coronary artery disease than control subjects, whereas the hexamer form was similar and the trimer form was significantly higher. During weight reduction in obese subjects, the HMW form increased and the trimer and hexamer forms decreased. Recombinant adiponectin dose-dependently suppressed apoptosis and caspase-3 activity in human umbilical vein endothelial cells (HUVECs). Transduction with dominant-negative AMP-activated protein kinase (AMPK) abolished the suppressive effect of adiponectin on HUVECs. Gel filtration chromatography was used to separate the adiponectin isoforms, and the antiapoptotic effect toward HUVECs was only observed with the HMW form. These data suggest that HMW adiponectin specifically confers the vascular-protective activities of this adipocytokine. The full text of this article is available online at http://circres.ahajournals.org.

AMP-Activated Protein Kinases↗
PubMed2004

Adiponectin, hepatocellular dysfunction and insulin sensitivity.

OBJECTIVE: Insulin resistance plays a major aetiological role in the development of fatty liver disease. Because adiponectin is a hepatic insulin sensitizer and also an inhibitor of tumour necrosis factor, a cytokine known to induce insulin resistance and liver damage, we wished to study whether low circulating adiponectin would be associated with higher serum concentrations of liver enzymes in healthy subjects. DESIGN: Cross-sectional, population-based study dealing with diabetes prevalence in northern Spain. PATIENTS: Two hundred and fifty-seven apparently healthy Caucasian subjects consecutively enrolled in the study. MEASUREMENTS: Adiponectin serum levels were measured by enzyme-linked immunosorbent assay (ELISA), liver function tests (LFTs) by colourimetry and insulin resistance by the homeostasis model of assessment (HOMA value). RESULTS: Adiponectin levels were negatively correlated with alanine aminotransferase (ALT) and gamma-glutamyltranspeptidase (GGT), before and after adjustment for sex, age, body mass index (BMI) and insulin resistance (ALT; r = -0.32, P < 0.001; adjusted: r = -0.13, P = 0.033; GGT; r = -0.31, P < 0.001; adjusted: r = -0.16, P = 0.011). Additionally, adiponectin correlated with alkaline phosphate (ALKP) only after adjusting for the same confounding variables (r =-0.10, P = 0.098; adjusted: r = -0.14, P = 0.031). A general linear model, adjusting for age, sex and BMI, was constructed to predict the decrease in circulating adiponectin for each LFT value (i.e. ALT, GGT and ALKP) above the median. Beyond one LFT value above the median, serum adiponectin decreased by -0.97 mg/l (95% CI -1.46 to -0.48). In multiple regression analysis, sex, BMI and adiponectin, but not insulin resistance, predicted serum concentrations of both ALT and GGT, explaining 19% and 14% of their variance, respectively. Age, BMI and adiponectin, but not sex or insulin resistance, explained 20% of ALKP variance. CONCLUSIONS: Adiponectin levels are associated in healthy humans with plasma concentrations of various liver function tests. The contributions of adiponectin to maintaining liver integrity through the regulation of both insulin sensitivity and/or the inflammatory response merit further studies.

Adiponectin↗
PubMed2004

Both intrauterine growth restriction and postnatal growth influence childhood serum concentrations of adiponectin.

OBJECTIVE: Insulin resistance has been linked to intrauterine growth restriction; adiponectin is a strong determinant of insulin sensitivity. We aimed at studying the contributions of birthweight and insulin sensitivity to circulating adiponectin in children born small for gestational age (SGA). DESIGN: Cross-sectional, hospital-based study dealing with insulin sensitivity in SGA children. PATIENTS: Thirty-two prepubertal children born SGA (age 5.4 +/- 2.9 years) and 37 prepubertal children born appropriate for gestational age (AGA, age 5.9 +/- 3.0 years). MEASUREMENTS: Serum levels of fasting glucose, serum lipids, insulin (immunometric assay) and adiponectin concentrations (ELISA) were assessed, and insulin resistance (IR) and insulin secretion (beta-cell) were calculated by the homeostasis model of assessment (HOMA). RESULTS: SGA children had similar HOMA-IR, HOMA-beta-cell and adiponectin concentrations than AGA children. However, in a separate analysis of subjects older than 3 years of age, SGA children showed higher HOMA-IR after adjusting for sex, age and body mass index (BMI) standard deviation score (SDS). Circulating adiponectin was higher in SGA children [adjusted means: 14.5 mg/l (95% CI 12.9-16.1) and 18.7 mg/l (95% CI 17.0-20.3) for AGA and SGA children, respectively; P < 0.0001]. Further analysis revealed that the group of overweight SGA (arbitrarily defined as being in the higher quartile for the BMI SDS distribution in the sample) had decreased serum concentrations of adiponectin, compared to lean SGA children [adjusted means: 12.9 mg/l (95% CI 9.3-16.5) vs. 19.0 (95% CI 16.8-21.3), respectively; P = 0.001]. In a multiple regression model, HOMA-IR and SGA status explained 35% and 15% of adiponectin variance, respectively. CONCLUSIONS: Prenatal growth restriction is associated with insulin resistance but relatively increased adiponectin concentrations, provided overweight does not ensue. The contributions of circulating adiponectin to the increased risks for developing insulin resistance and type-2 diabetes in formerly SGA subjects merit further studies.

Adiponectin↗
PubMed2004

Adiponectin as a biomarker of the metabolic syndrome.

BACKGROUND: The metabolic syndrome, a cluster of abdominal obesity, dyslipidemia, hypertension and hyperglycemia, is a common basis for atherosclerotic vascular diseases in industrial countries exposed to overnutrition. Adiponectin is an adipose-derived plasma protein with anti-atherogenic and insulin-sensitizing activities. METHODS AND RESULTS: A total of 661 Japanese adults (479 men, 53+/-10 years; 182 women 56+/-10 years) were enrolled. Plasma adiponectin concentrations correlated negatively with waist circumference, visceral fat area, serum triglyceride concentration, fasting plasma glucose, fasting plasma insulin, and systolic and diastolic blood pressure in both sexes. A positive correlation was found between plasma adiponectin and high-density lipoprotein cholesterol concentrations in both sexes. The mean number of components of the metabolic syndrome increased as the plasma adiponectin concentration decreased: 2.57+/-1.34 for men and 2.00+/-1.51 for women with adiponectin concentrations <4.0 microg/ml. In all, 52.3% of men and 37.5% of women with adiponectin concentrations <4.0 microg/ml fulfilled the criteria for metabolic syndrome. CONCLUSION: Hypoadiponectinemia is closely associated with the clinical phenotype of the metabolic syndrome and measuring the plasma concentration of adiponectin may be useful for management of the metabolic syndrome.

Adiponectin↗
PubMed2004

Adiponectin is independently associated with glycosylated haemoglobin.

BACKGROUND: In humans, adiponectin has been demonstrated to circulate in inverse proportion to the degree of insulin resistance. OBJECTIVE: To investigate the association between adiponectin and glycosylated haemoglobin (HbA1c) in a population-based study. DESIGN AND METHODS: Two hundred and ninety-seven individuals aged 30-75 years were enrolled in a cross-sectional study. They included patients with type 2 (non-insulin-dependent) diabetes mellitus and stable, good metabolic control (n=32) and individuals with glucose intolerance (n=54). Adiponectin was measured using a sandwich enzyme-linked immunosorbent assay (intra-assay and interassay coefficients of variation 3.3 and 7.4% respectively). RESULTS: Adiponectin correlated with age (r=0.161; P=0.006), body mass index (r=-0.197; P=0.001), diastolic blood pressure (r=-0.181; P=0.005), fasting glucose and HbA1c (r=-0.251 and r=-0.22 respectively; P<0.0001), high-density lipoprotein cholesterol (r=0.442; P<0.001) and serum triglycerides (r=-362; P<0.001). In multiple regression analysis, sex, age, fasting and post-load glucose, and adiponectin independently contributed to 40% of the variance in HbA1c. Among individuals with normal glucose tolerance, fasting glucose (P=0.0033), post-load glucose (P=0.0015), age (P=0.001) and adiponectin (P=0.0083) independently contributed to 21% of the variance in HbA1c. CONCLUSION: Adiponectin is significantly associated with altered glucose metabolism and independently contributes to the variance of HbA1c in a population-based manner.

Adiponectin↗
PubMed2004

Effect of moderate alcohol consumption on adiponectin, tumor necrosis factor-alpha, and insulin sensitivity.

OBJECTIVE: Epidemiological studies suggest that moderate alcohol consumers have enhanced insulin sensitivity and a reduced risk of type 2 diabetes. Adiponectin, an adipocyte-derived plasma protein, has been found to be negatively associated with adiposity and positively associated with insulin sensitivity. Moderate alcohol consumption may increase adiponectin, which in turn causes a decrease of tumor necrosis factor (TNF)-alpha. A decreased TNF-alpha level may consequently increase insulin sensitivity. RESEARCH DESIGN AND METHODS: To test this hypothesis, we performed a randomized crossover partially diet-controlled study. A total of 23 healthy middle-aged male subjects consumed daily four glasses of whisky (40 g ethanol) or tap water with dinner during two successive periods of 17 days. RESULTS: Moderate alcohol consumption increased plasma adiponectin level (11%; P = 0.0002) but did not affect plasma TNF-alpha level. An increase in insulin sensitivity index was observed in an insulin-resistant subgroup (21%; P = 0.11), which positively correlated with the relative alcohol-induced increase in plasma adiponectin level (r = 0.73, P = 0.02). CONCLUSIONS: The experimental results are in agreement with observational data. Moderate alcohol consumption improved insulin sensitivity in relatively insulin-resistant middle-aged men, an effect that may be mediated through alcohol-induced increases in adiponectin.

Adiponectin↗
PubMed2003

Divergent effects of soy protein diet on the expression of adipocytokines.

Adipose tissue secretes various bioactive molecules called adipocytokines. Dysregulation of adipocytokines plays an important role in the development of atherosclerotic vascular diseases. Consumption of vegetable protein reduces the risks of atherosclerotic vascular diseases. Here, we investigated the effects of 10-day dietary soy protein isolate (SPI) on the regulation of adipocytokines in Wistar rats. No significant difference in body weight was observed between SPI and Casein (animal protein) group. Expression of adipose PAI-1 was lower and expression and plasma concentration of adiponectin were higher in SPI than Casein group. Triglyceride content was lower and fatty acid synthase mRNA level in adipose tissue was lower in SPI than Casein group. Although SREBP-1 mRNA expression was decreased in the liver of SPI group, adipose SREBP and PPARgamma mRNA levels remained unchanged. Our data suggest that dietary SPI alters the gene expressions in adipose tissue and has beneficial effects on the expression of adipocytokines.

Adipose Tissue↗
PubMed2003

Association of serum adiponectin levels with breast cancer risk.

PURPOSE: Adiponectin is a peptide hormone secreted from the adipose tissue, affecting the proliferation and insulin sensitivity of various types of cells. Because association of obesity with breast cancer risk is well established, it is possible that adiponectin plays some role in the development of breast cancer. Thus, in the present study, the association of the serum adiponectin levels with breast cancer risk was investigated. EXPERIMENTAL DESIGN: A case-control study was conducted on 102 breast cancer patients (cases) and 100 healthy women (controls). The serum adiponectin levels of cases and controls were examined in their association with breast cancer risk after adjustment for the various classical risk factors (family history, age at menarche, parity, body mass index, and so forth). In addition, the relationship between the serum adiponectin levels and the various clinicopathological characteristics of breast cancers was studied. RESULTS: Women in the low tertile of serum adiponectin levels were associated with a significantly (P < 0.005) increased risk for breast cancer compared with women in the high tertile [odds ratio (OR), 3.63; 95% confidence interval (CI), 1.61-8.19]. Such an association was observed both in the premenopausal women (OR, 3.46; 95% CI, 0.89-13.50) and in the postmenopausal women (OR, 3.90; 95% CI, 1.23-12.44). The frequency of large (>2 cm) tumors and that of high histological grade (2+3) tumors were significantly (P < 0.005 and P < 0.05, respectively) higher in breast cancer patients in the low tertile of the serum adiponectin levels than those in the high and intermediate tertiles. CONCLUSIONS: These results suggest that the low serum adiponectin levels are significantly associated with an increased risk for breast cancer and that tumors arising in women with the low serum adiponectin levels are more likely to show a biologically aggressive phenotype. The association between obesity and breast cancer risk might be partly explained by adiponectin.

Adiponectin↗
PubMed2003

Adiponectin stimulates angiogenesis by promoting cross-talk between AMP-activated protein kinase and Akt signaling in endothelial cells.

Adiponectin is an adipocyte-specific adipocytokine with anti-atherogenic and anti-diabetic properties. Here, we investigated whether adiponectin regulates angiogenic processes in vitro and in vivo. Adiponectin stimulated the differentiation of human umbilical vein endothelium cells (HUVECs) into capillary-like structures in vitro and functioned as a chemoattractant in migration assays. Adiponectin promoted the phosphorylation of AMP-activated protein kinase (AMPK), protein kinase Akt/protein kinase B, and endothelial nitric oxide synthesis (eNOS) in HUVECs. Transduction with either dominant-negative AMPK or dominant-negative Akt abolished adiponectin-induced eNOS phosphorylation as well as adiponectin-stimulated HUVEC migration and differentiation. Dominant-negative AMPK also inhibited adiponectin-induced Akt phosphorylation, suggesting that AMPK is upstream of Akt. Dominant-negative Akt or the phosphatidylinositol 3-kinase inhibitor LY294002 blocked adiponectin-stimulated Akt and eNOS phosphorylation, migration, and differentiation without altering AMPK phosphorylation. Finally, adiponectin stimulated blood vessel growth in vivo in mouse Matrigel plug implantation and rabbit corneal models of angiogenesis. These data indicate that adiponectin can function to stimulate the new blood vessel growth by promoting cross-talk between AMP-activated protein kinase and Akt signaling within endothelial cells.

AMP-Activated Protein Kinases↗
PubMed2003

Adiponectin and metabolic syndrome.

In this review article, the crucial roles of adipocytes in the development of so-called metabolic syndrome and vascular disease are reviewed, focusing on adipocyte-derived bioactive substances, adipocytokines. Recent progress in adipocyte biology shows that adipocytes are not merely energy-storing cells but that they secrete a variety of hormones cytokines, growth factors, and other bioactive substances. To search for novel adipocytokines by the large-scale random sequence analysis of expressed genes in adipocytes, we identified an adipose-specific collagen-like molecule, adiponectin. This novel adipocytokine has plural biofunctions, such as antidiabetic, antiatherosclerotic, and antiinflammatory functions. Adiponectin plasma levels decrease with the accumulation of visceral adipose tissue. In this review, we discuss the link of adiponectin to visceral adiposity, insulin resistance, and vascular diseases.

Adipocytes↗
PubMed2003

Association of hypoadiponectinemia with impaired vasoreactivity.

Endothelial dysfunction is a crucial feature in the evolution of atherosclerosis. Adiponectin is an adipocyte-specific plasma protein with antiatherogenic and antidiabetic properties. In the present study, we investigated the relation between adiponectin and endothelium-dependent vasodilation. We analyzed endothelial function in 202 hypertensive patients, including those who were not taking any medication. Forearm blood flow was measured by strain-gauge plethysmography. Plasma adiponectin level was highly correlated with the vasodilator response to reactive hyperemia in the total (r=0.257, P<0.001) and no-medication (r=0.296, P=0.026) groups but not with nitroglycerin-induced hyperemia, indicating that adiponectin affected endothelium-dependent vasodilation. Multiple regression analysis of data from all hypertensive patients revealed that plasma adiponectin level was independently correlated with the vasodilator response to reactive hyperemia. Vascular reactivity was also analyzed in aortic rings from adiponectin-knockout (KO) and wild-type (WT) mice. Adiponectin-KO mice showed obesity, hyperglycemia, and hypertension compared with WT mice after 4 weeks on an atherogenic diet. Endothelium-dependent vasodilation in response to acetylcholine was significantly reduced in adiponectin-KO mice compared with WT mice, although no significant difference was observed in endothelium-independent vasodilation in response to sodium nitroprusside. Our observations suggest that hypoadiponectinemia is associated with impaired endothelium-dependent vasorelaxation and that the measurement of plasma adiponectin level might be helpful as a marker of endothelial dysfunction.

Acetylcholine↗