scholarly journals Effects of insulin resistance and testosterone on the participation of cyclooxygenase isoforms in vascular reactivity

2010 ◽  
pp. 169
Author(s):  
McNeill ◽  
Lau ◽  
Jiang ◽  
Vasudevan
Keyword(s):  
Insulin Resistance ◽  
Vascular Reactivity ◽  
Cyclooxygenase Isoforms

Abstract 2474: Rho-Kinase Inhibition Improves Endothelium-Dependent Vasodilation during Hyperinsulinemia in Patients with Metabolic Syndrome

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Francesca Schinzari ◽  
Manfredi Tesauro ◽  
Valentina Rovella ◽  
Augusto Veneziani ◽  
Nadia Mores ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Vascular Function ◽  
Vascular Reactivity ◽  
Rho Kinase ◽  
Serine Phosphorylation ◽  
No Donor ◽  
Kinase Inhibition ◽  
Impaired Insulin

Impaired insulin-mediated vasodilation in the skeletal muscle may be involved in the development of hypertension in patients with metabolic syndrome (MetS) and contribute to insulin resistance by diminishing the glucose uptake. Rho-kinase, an effector of the small G protein Rho A, plays an important role in hypertension and is reported to interfere with insulin signaling through serine phosphorylation of insulin receptor substrate-1 in blood vessels. We therefore examined the role of Rho-kinase in the pathophysiology of impaired vascular reactivity in patients with MetS by evaluating the effect of Rho-kinase inhibition on NO-dependent vasodilation during hyperinsulinemia. Forearm blood flow (FBF) responses to acetylcholine (ACh), a stimulus for endothelial release of NO, and sodium nitroprusside (SNP), an exogenous NO donor, were assessed during insulin administration (0.1 mU/Kg/min) using the forearm perfusion technique in patients with MetS (n=10) and matched controls (n=10). Patients with MetS were then randomized to intra-arterial infusion of either fasudil (inhibitor of Rho-kinase, 200 μg/min) or placebo and reactivity to ACh and SNP was reassessed. During hyperinsulinemia, vasodilator responses to both ACh and SNP were blunted in patients with MetS (both P>0.001 vs. controls). In patients who received fasudil, its administration did not change unstimulated FBF (P=0.75 vs. insulin alone); the vasodilator response to ACh, however, was significantly enhanced by fasudil (P=0.009 vs. insulin alone), while the response to SNP was not significantly changed (P=0.56). In patients with MetS who received placebo, vascular reactivity to both ACh and SNP was not different than before (both P>0.05). In conclusion, Rho-kinase inhibition during hyperinsulinemia improves endothelium-dependent vasodilator responsiveness in patients with MetS. This suggests that, under those conditions, intravascular activation of Rho-kinase is involved in the pathophysiology of endothelial dysfunction and may constitute a critical mediator linking metabolic and hemodynamic abnormalities in insulin resistance. As a consequence, targeting Rho-kinase might beneficially impact both vascular function and insulin sensitivity in patients with MetS.

Obesity augments vasoconstrictor reactivity to angiotensin II in the renal circulation of the Zucker rat

2007 ◽  
Vol 293 (4) ◽  
pp. H2537-H2542 ◽  
Author(s):  
David W. Stepp ◽  
Erika I. Boesen ◽  
Jennifer C. Sullivan ◽  
James D. Mintz ◽  
Clark D. Hair ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Angiotensin Ii ◽  
Vascular Reactivity ◽  
Sodium Intake ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Zucker Rats ◽  
Ang Ii ◽  
Renal Vasoconstriction ◽  
Insulin Resistant

Obesity is an emerging risk factor for renal dysfunction, but the mechanisms are poorly understood. Obese patients show heightened renal vasodilation to blockade of the renin-angiotensin system, suggesting deficits in vascular responses to angiotensin II (ANG II). This study tested the hypothesis that obesity augments renal vasoconstriction to ANG II. Lean (LZR), prediabetic obese (OZR), and nonobese fructose-fed Zucker rats (FF-LZR) were studied to determine the effects of obesity and insulin resistance on reactivity of blood pressure and renal blood flow to vasoconstrictors. OZR showed enlargement of the kidneys, elevated urine output, increased sodium intake, and decreased plasma renin activity (PRA) vs. LZR, and renal vasoconstriction to ANG II was augmented in OZR. Renal reactivity to norepinephrine and mesenteric vascular reactivity to ANG II were similar between LZR and OZR. Insulin-resistant FF-LZR had normal reactivity to ANG II, indicating the insulin resistance was an unlikely explanation for the changes observed in OZR. Four weeks on a low-sodium diet (0.08%) to raise PRA reduced reactivity to ANG II in OZR back to normal levels without effect on LZR. From these data, we conclude that in the prediabetic stages of obesity, a decrease in PRA is observed in Zucker rats that may lead to increased renal vascular reactivity to ANG II. This increased reactivity to ANG II may explain the elevated renal vasodilator effects observed in obese humans and provide insight into early changes in renal function that predispose to nephropathy in later stages of the disease.

Cardioprotective and antihypertensive effects of Enicostemma littorale Blume extract in fructose-fed rats

2012 ◽  
Vol 90 (8) ◽  
pp. 1065-1073 ◽  
Author(s):  
Niraj M. Bhatt ◽  
Meenal Chavda ◽  
Dipali Desai ◽  
Rishit Zalawadia ◽  
Vaibhav B. Patel ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vascular Reactivity ◽  
Therapeutic Potential ◽  
Serum Levels ◽  
Cardiovascular Complications ◽  
Oral Glucose ◽  
Protective Effects ◽  
High Fructose ◽  
Enicostemma Littorale ◽  
High Level

We investigated the protective effects of Enicostemma littorale Blume (EL) extract on hypertension and insulin resistance along with its associated cardiovascular complications in high fructose (HF) fed rats. For this, rats were divided among 4 groups: (i) control, fed laboratory chow; (ii) fed with a high level of fructose; (iii) fed with a high level of fructose plus E. littorale extract; and (iv) fed with a high level of fructose plus rosiglitazone (Rg). EL and Rg treatments were given simultaneously with HF diet. The results show that untreated HF-fed rats showed altered oral glucose tolerance, increased fasting insulin, and increased fasting glucose. These rats also exhibited hypertriglyceridemia, moderate hypertension, platelet hyperaggregability, decreased prothrombin time, activated partial thromboplastin time, altered vascular reactivity, and increased serum levels of enzymes (creatine kinase, type muscle–brain (CK-MB), aspartate aminotransferase (SGOT), lactate dehydrogenase (LDH), and alanine aminotransferase (SGPT). This is the first demonstration of platelet hyperaggregation and prothrombotic alteration in HF-fed rats. HF-fed rats treated with EL showed improved insulin resistance, along with reduced hypertriglyceridemia, hypertension, platelet aggregability, blood coagulation, serum enzymes (CK-MB, SGOT, LDH and SGPT), and vascular reactivity. These effects of EL in HF-induced hypertensive rats might be associated with the suppression of hyperinsulinemia and hypertriglyceridemia, along with its antiatherogenic and antithrombogenic potential. These data indicate that the aqueous extract of EL has great therapeutic potential for the prevention and (or) management of insulin resistance and the associated hypertension.

scholarly journals NORMAL VASCULAR REACTIVITY IS RESTORED BY APIGENIN IN DIABETIC RATS

2018 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Hany M. El-bassossy ◽  
Nora Desoky ◽  
Abdulrahman M Alahdal ◽  
Ahmed Fahmy
Keyword(s):  
Insulin Resistance ◽  
Potassium Chloride ◽  
Sodium Nitroprusside ◽  
Vascular Reactivity ◽  
Antioxidant Properties ◽  
Diabetic Rats ◽  
Insulin Deficiency ◽  
Insulin Resistant ◽  
The Impact

Objective: Diabetes is a disease whose complications have serious implications for the health of sufferers; one of the most serious such complications is the deterioration of vascular reactivity. Apigenin is a natural flavonoid with PKC inhibiting and antioxidant properties. In this study, the impact of apigenin on vascular reactivity deterioration was investigated.Methods: Insulin resistance (IR) and insulin deficiency (ID) were induced by fructose and streptozotocin respectively. The isolated aortae vasoconstriction response to phenylephrine (PE) and potassium chloride (KCl) in addition to the vasodilation response to acetylcholine (ACh) and sodium nitroprusside (SNP) were tested.Results: IR and ID were associated with significantly exaggerated vasoconstriction to KCl and PE while significantly impaired vasodilation to ACh. Response to SNP was not significantly affected by both IR and ID. In vitro incubation with apigenin (7 7µM) for 20 min restored normal responses to PE, KCl and ACh in aortae isolated from insulin-resistant or insulin-deficient rats. Incubation for one hour with the PKC stimulant, phorbol 12-myristate 13-acetate (PMA, 800 nM) resulted in aortic impairment similar to that seen in aortae isolated from IR and ID animals. Incubation with both apigenin prevented PMA-induced exaggerated vasoconstriction response to both PE and KCl.Conclusion: Apigenin alleviates vascular exaggerated vasoconstriction and impaired dilation associated with diabetes or PKC activated.

scholarly journals Associations Among Indices of Insulin Resistance and Vascular Reactivity in Older, Obese Adults

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 665-666
Author(s):  
Matthew D. Doyle ◽  
Vincent M. Simth ◽  
Gabrielle A. Volk ◽  
Kevin D. Ballard ◽  
Kyle L. Timmerman
Keyword(s):  
Insulin Resistance ◽  
Vascular Reactivity ◽  
Obese Adults

Relationship Between Fitness, Insulin Resistance, and Vascular Reactivity to Mental Challenge in Young Females

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S435
Author(s):  
Young J. Park ◽  
Justin R. Jones ◽  
Yati N. Boutcher ◽  
Gail E. Trapp ◽  
Stephen H. Boutcher
Keyword(s):  
Insulin Resistance ◽  
Vascular Reactivity ◽  
Young Females

scholarly journals Endothelial Estrogen Receptor-α Does Not Protect Against Vascular Stiffness Induced by Western Diet in Female Mice

Endocrinology ◽  
2016 ◽  
Vol 157 (4) ◽  
pp. 1590-1600 ◽  
Author(s):  
Camila Manrique ◽  
Guido Lastra ◽  
Francisco I. Ramirez-Perez ◽  
Dominic Haertling ◽  
Vincent G. DeMarco ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Estrogen Receptor ◽  
Vascular Reactivity ◽  
Control Diet ◽  
Western Diet ◽  
Vascular Stiffness ◽  
Whole Body ◽  
Chow Diet ◽  
Female Mice ◽  
Vascular Stiffening

Abstract Consumption of a diet high in fat and refined carbohydrates (Western diet [WD]) is associated with obesity and insulin resistance, both major risk factors for cardiovascular disease (CVD). In women, obesity and insulin resistance abrogate the protection against CVD likely afforded by estrogen signaling through estrogen receptor (ER)α. Indeed, WD in females results in increased vascular stiffness, which is independently associated with CVD. We tested the hypothesis that loss of ERα signaling in the endothelium exacerbates WD-induced vascular stiffening in female mice. We used a novel model of endothelial cell (EC)-specific ERα knockout (EC-ERαKO), obtained after sequential crossing of the ERα double floxed mice and VE-Cadherin Cre-recombinase mice. Ten-week-old females, EC-ERαKO and aged-matched genopairs were fed either a regular chow diet (control diet) or WD for 8 weeks. Vascular stiffness was measured in vivo by pulse wave velocity and ex vivo in aortic explants by atomic force microscopy. In addition, vascular reactivity was assessed in isolated aortic rings. Initial characterization of the model fed a control diet did not reveal changes in whole-body insulin sensitivity, aortic vasoreactivity, or vascular stiffness in the EC-ERαKO mice. Interestingly, ablation of ERα in ECs reduced WD-induced vascular stiffness and improved endothelial-dependent dilation. In the setting of a WD, endothelial ERα signaling contributes to vascular stiffening in females. The precise mechanisms underlying the detrimental effects of endothelial ERα in the setting of a WD remain to be elucidated.

Diet-induced endothelial dysfunction in the rat is independent of the degree of increase in total body weight

2001 ◽  
Vol 100 (6) ◽  
pp. 635-641 ◽  
Author(s):  
Ebrahim K. NADERALI ◽  
Lucy C. PICKAVANCE ◽  
John P. H. WILDING ◽  
Gareth WILLIAMS
Keyword(s):  
Insulin Resistance ◽  
Weight Gain ◽  
Wistar Rats ◽  
Vascular Reactivity ◽  
Total Body Weight ◽  
Mesenteric Arteries ◽  
Cafeteria Diet ◽  
Syndrome X ◽  
Fat Pad ◽  
High Weight Gain

A growing number of studies indicate an association between obesity, insulin resistance, dyslipidaemia and cardiovascular disorders, collectively known as Syndrome X. In this study we have aimed to produce a model of Syndrome X by voluntary feeding of Wistar rats with a highly palatable cafeteria diet, and examined its effects on metabolic changes and vascular reactivity of Wistar rats. At the end of the experiment, the cafeteria-diet fed group was divided into two groups of low weight gain (LWG) and high weight gain (HWG). Both LWG and HWG groups had significantly (P < 0.01) higher fat-pad mass than their chow-fed counterparts, while gastrocnemius muscle mass were comparable. All cafeteria-diet fed rats had significantly (P < 0.01) raised plasma triacylglycerol (TG) levels whereas plasma non-esterified fatty acids, glucose and insulin levels were similar between chow-fed and cafeteria-diet fed rats. Vasorelaxation responses to acteylcholine, insulin and sodium nitroprusside were significantly (P < 0.01) attenuated in cafeteria-diet fed animals; however, there were no differences in contractile responses of the mesenteric arteries to noradrenaline or KCl between the groups. Multiple regression analysis showed a significant (P < 0.05) negative association between plasma TG levels and reduction in acetylcholine-induced vasorelaxation. Acetylcholine-induced vasorelaxation was also significantly (P < 0.05) associated with the amount of fat-pad mass. These data suggest that diet-induced vascular dysfunction can occur in the absence of insulin resistance, and that plasma TGs may have a detrimental effect on vascular reactivity.

Vascular responses to α-adrenergic stimulation and depolarization are enhanced in insulin-resistant and diabetic Psammomys obesus

2003 ◽  
Vol 81 (7) ◽  
pp. 704-710 ◽  
Author(s):  
M Zoltowska ◽  
J St-Louis ◽  
E Ziv ◽  
B Sicotte ◽  
E E Delvin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vascular Reactivity ◽  
Vascular Complications ◽  
Psammomys Obesus ◽  
Adrenergic Stimulation ◽  
Endothelial Lining ◽  
Insulin Resistant ◽  
Group A ◽  
Group B ◽  
Endothelium Dependent Relaxation

Since vascular complications often accompany diabetes, we examined the influence of the endothelial lining on vascular reactivity in Psammomys obesus, a desert gerbil that acquires insulin resistance and diabetes when exposed to a laboratory diet. Vasoconstriction to phenylephrine and depolarizing KCl, as well as carbachol endothelium-dependent relaxation, were assessed in rings of thoracic aortae obtained from three groups: (i) group A, normoglycemic–normoinsulinemic; (ii) group B, normoglycemic–hyperinsulinemic, and (iii) group C, hyperglycemic–hyperinsulinemic animals. As expected, marked hypertriglyceridemia and hypercholesterolemia characterized groups B and C, which developed enhanced contractile responsiveness to phenylephrine and KCl compared with controls (group A). Furthermore, both experimental groups displayed a significant decrease in endothelium-dependent relaxation to carbachol. Altered lipid profiles are considered to play some role in the observed modification of aortic reactivity. Overall, our data indicate that vascular contractile responsiveness is enhanced early in the development of insulin resistance and diabetes in the female P. obesus.Key words: insulin resistance, diabetes, vascular reactivity, LDL-cholesterol, hypertriglyceridemia.

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