(Hypertension. 2001;38:884.)
© 2001 American Heart Association, Inc.
Scientific Contributions |
From the Muscle Metabolism Laboratory, Department of Physiology, University of Arizona College of Medicine (E.J.H., T.R.K., M.K.T.), Tucson; Department of Endocrinology, Eberhard-Karls University (S.J.), Tübingen, Germany; and Bristol-Myers Squibb (M.K.), Munich, Germany.
Correspondence to Erik J. Henriksen, PhD, Department of Physiology, Ina E. Gittings Bldg 93, University of Arizona, Tucson, AZ 85721-0093. E-mail ejhenrik{at}u.arizona.edu
| Abstract |
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Key Words: irbesartan glucose muscle, skeletal transport, glucose rats, Zucker receptors, angiotensin
| Introduction |
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We have recently shown that acute oral administration of an Ang II (AT1-subtype) receptor antagonist (eprosartan) has no significant effect on in vitro insulin-stimulated glucose transport activity in type IIb muscle (epitrochlearis) of the insulin-resistant obese Zucker rat.19 In contrast, chronic administration of Ang II receptor antagonists to insulin-resistant fructose-fed12 or spontaneously hypertensive20 rats or to human subjects with essential hypertension21 leads to significant improvements in whole-body insulin sensitivity. Moreover, Rao22 and Richey et al23 have reported that acute infusion of Ang II leads to substantial reduction in glucose disposal in normal skeletal muscle, which could not be attributed to hemodynamic alterations.23 To our knowledge, neither the acute effects of specific Ang II receptor antagonism on insulin-stimulated glucose transport in insulin-resistant type I skeletal muscle (eg, soleus) nor the chronic effects of Ang II receptor antagonism on the skeletal-muscle glucose transport system in conditions of insulin resistance have been investigated.
In this context, the purpose of the present study was to assess in an animal model of skeletal-muscle insulin resistance, hyperinsulinemia, glucose intolerance, and dyslipidemia (obese Zucker fa/fa rat) the effects of acute or chronic treatment with a specific Ang II receptor (AT1-subtype) antagonist, irbesartan, on whole-body glucose disposal and on in vitro insulin-stimulated skeletal-muscle glucose transport activity. This latter approach has the advantage of allowing for assessment of adaptive responses in the skeletal-muscle glucose transport system independent of any potential hemodynamic influences. In addition, the potential role of alterations in expression of skeletal-muscle glucose transporter-4 (GLUT-4) protein in the regulation of insulin-stimulated glucose transport activity after chronic antagonism of Ang II receptors was investigated.
| Methods |
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Oral Glucose Tolerance Tests
Animals were food restricted (4 g of chow given at 5:00 PM) the evening before the experiment. Between 8:00 and 10:00 AM, 1 hour (acute study) or
12 hours (chronic study) after the most recent treatment, animals underwent an oral glucose tolerance test (OGTT) with a 1-g/kg body wt glucose feeding by gavage. Blood was drawn from a cut at the tip of the tail at 0, 30, 60, 90, and 120 minutes after the glucose feeding. Whole blood was mixed thoroughly with EDTA (18 mmol/L final concentration) and centrifuged at 13 000g to separate the plasma. Plasma samples were analyzed for glucose (Sigma Chemical Co), insulin (Linco Research Inc), and free fatty acids (Wako Chemicals USA Inc). Immediately after completion of the OGTT, all animals received 2.5 mL SC of sterile 0.9% saline to compensate for plasma loss. In the acute study, animals remained untreated for 3 days after OGTT and then received a second acute administration of the same dosage level of irbesartan. In the chronic study, treatments resumed for 3 days.
Glucose Transport Activity
In the acute study, animals were again food restricted as described above before receiving a second acute dose of irbesartan. In the chronic study, animals were likewise food restricted. Between 8:00 and 10:00 AM, 1 hour after the second acute dose or
12 hours after final chronic treatment with irbesartan, animals were deeply anesthetized with pentobarbital sodium (50 mg/kg IP). Both epitrochlearis muscles and 1 soleus muscle were surgically removed and prepared for in vitro incubation. Epitrochlearis muscles were incubated intact, whereas soleus muscles were prepared in strips (weight,
25 mg).24 Glucose transport activity, assessed as 2-deoxyglucose (2-DG) uptake, was determined in the absence of presence of insulin (13.3 nmol/L) exactly as described previously.710,19
Muscle GLUT-4 Protein
In the chronic study, the contralateral soleus and plantaris and the heart were removed, quickly frozen in liquid N2, weighed, and stored at -80°C until processed. Muscles and left ventricle of the heart were homogenized in 20 vol of ice-cold buffer containing 20 mmol/L HEPES, 1 mmol/L EDTA, and 250 mmol/L sucrose, pH 7.4. Total protein concentration was determined by use of the bicinchoninic acid method (Sigma). GLUT-4 protein was assayed as described previously.10
Statistical Analysis
All data are presented as mean±SE. Significance of differences between multiple groups was assessed by ANOVA with a post hoc Fisher Protected Least Significant Difference Test. Differences between groups were determined by an unpaired Student t test. Statistical significance was set at the 0.05 probability level.
An expanded Methods section can be found in an online data supplement available at http://www.hypertensionaha.org.
| Results |
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Total areas under the curve (AUC) for these glucose and insulin responses and the glucose-insulin index (the product of glucose AUC and insulin AUC; a reduction in this value reflects an increase in whole-body insulin sensitivity25), are presented in Figure 1, bottom. Whereas the reductions in the obese group treated with 25 mg/kg irbesartan did not reach statistical significance, animals treated with 50 mg/kg irbesartan displayed significant reductions in glucose (13%; P<0.05) and insulin (15%; P<0.05) AUC. The glucose-insulin index was significantly reduced (17%; P<0.05) in the 25 mg/kg irbesartan-treated group, with the greatest diminution (26%; P<0.05) in this variable observed in the 50 mg/kg irbesartan-treated group.
To identify the potential cellular locus for the improvements in whole-body insulin sensitivity brought about by acute irbesartan treatment, insulin action on isolated skeletal muscle from the obese animals was assessed (Figure 2). In the epitrochlearis, which consists primarily of less-insulin-sensitive type IIb fibers,24,26 no increases were seen either in the rate of insulin-stimulated 2-DG uptake (Figure 2, top left) or in the insulin-mediated increase (increase over basal) in 2-DG uptake (Figure 2, top right) after acute irbesartan treatment. In contrast, acute treatment of the obese animals with irbesartan was associated with enhanced insulin action in the soleus, which consists mainly of more-insulin-responsive type I fibers.24,27 After animals were treated with either 25 or 50 mg/kg of irbesartan, both the rates of insulin-stimulated 2-DG uptake (18% for both dosages; P<0.05) and insulin-mediated 2-DG uptake (41% and 50%, respectively; both P<0.05) were increased in the soleus. Enhancement of insulin-mediated 2-DG uptake in soleus but not epitrochlearis after acute treatment with irbesartan was correlated significantly (r=-0.732; P<0.05) with improvement in whole-body insulin sensitivity (reduction in glucose-insulin index; Figure 3).
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Chronic Administration of Irbesartan
The highest effective acute dose, 50 mg/kg, was chosen to assess the effect of chronic irbesartan treatment on insulin action in the obese Zucker rat. Final body weights did not differ between groups (Table). The positive systemic influence of chronic irbesartan treatment was demonstrated by a 18%-lower heart weight in the irbesartan-treated versus the vehicle-treated group. Whereas chronic irbesartan treatment elicited a significant lowering (14%; P<0.05) of plasma glucose in food-restricted obese animals, this treatment regimen did not significantly alter plasma insulin or free fatty acid levels (Table).
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Chronic irbesartan treatment lowered significantly both glucose (17% to 21%; P<0.05) and insulin (25% at 90 minutes and 29% at 120 minutes, P<0.05) responses during OGTT (Figure 4, top). Likewise, the glucose (19%; P<0.05) and insulin (21%; P<0.05) AUC and the glucose-insulin index (34%; P<0.05) were all significantly less in the chronic irbesartan-treated versus the vehicle-treated obese groups (Figure 4, bottom).
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Insulin-stimulated rate of 2-DG uptake and insulin-mediated increase in 2-DG uptake in both epitrochlearis (21% and 32%, respectively; P<0.05) and soleus (40% and 73%, respectively; P<0.05) muscles were significantly enhanced after chronic irbesartan treatment (Figure 5). These improvements in insulin-mediated 2-DG uptake in skeletal muscle after chronic irbesartan treatment were significantly correlated with enhancement of whole-body insulin sensitivity, as assessed by reduction in the glucose-insulin index (epitrochlearis, r=-0.677; soleus, r=-0.892; both P<0.05; Figure 6). Importantly, chronic treatment with irbesartan elicited a significant enhancement (22%; P<0.05) in GLUT-4 protein level in the soleus muscle (Figure 7). Similarly small but significant increases in GLUT-4 protein expression after chronic Ang II receptor antagonism were observed in the mixed-type IIa/IIb plantaris muscle (20%; P<0.05) and in myocardium (15%; P<0.05).
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| Discussion |
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Whole-body insulin sensitivity, as reflected in the reduced glucose-insulin index by use of glucose and insulin responses during OGTT, was significantly enhanced in obese Zucker rats by acute administration of irbesartan (Figure 1) and, to an even greater extent, after chronic treatment with this Ang II receptor antagonist (Figure 4). At least part of these increases in whole-body glucose disposal was the result of an enhanced capacity for insulin-mediated glucose transport in skeletal muscle, given that significant correlations between the glucose-insulin index and the insulin-mediated increase in 2-DG uptake were found for the soleus after acute irbesartan treatment (Figure 3) and for both the epitrochlearis and soleus after chronic Ang II receptor antagonism (Figure 6). Whereas a portion of these improvements in whole-body insulin action can be attributed to the well-documented hemodynamic modifications elicited by Ang II receptor antagonists,35 both the acute and chronic treatments with irbesartan resulted in upregulation of the skeletal-muscle glucose transport system: increases observed in insulin-stimulated 2-DG uptake in the epitrochlearis (chronic treatment only) and soleus (acute and chronic treatments) were assessed in vitro and therefore were independent of hemodynamic influences. In addition, in light of the small but significant effects of chronic irbesartan treatment for reduction of fasting plasma glucose (Table), the possibility exists that Ang II receptor antagonism may enhance hepatic insulin sensitivity and diminish hepatic glucose production in the fasting state.
Present findings support and extend previous investigations that demonstrate that inhibition of Ang II formation, either through administration of ACE inhibitors6,810,1318 or through specific inhibition of Ang II action at AT1 receptors,11,12,20 frequently is associated with enhancement of whole-body insulin sensitivity in a variety of insulin-resistant animal models or in insulin-resistant humans with essential hypertension. Whereas the vasodilatory effects of these interventions account for some of the whole-body metabolic improvements,3,4 the present results point toward an additional important contribution of the insulin-dependent glucose transport system in skeletal muscle to the beneficial metabolic effects of these compounds. Reports of the metabolic neutrality of Ang II receptor antagonists in conditions of hypertension11,18,2830 may be related to the apparent dosage-dependency of the effects of these compounds on insulin action (see Figures 1 through 3); dosages that elicit lowering of blood pressure were ineffective for bringing about increased insulin sensitivity. Future investigations should be designed to address this possibility specifically.
The role of the whole-muscle expression of GLUT-4 protein in the capacity of that muscle for insulin-mediated glucose transport activity has long been recognized.24,31 In the present investigation, we found that chronic antagonism of Ang II receptors caused small (15% to 22%) but significant increases in GLUT-4 protein expression in both oxidative (soleus) and substantially glycolytic (plantaris) skeletal muscle and in the highly oxidative myocardium (Figure 7). At least in the soleus muscle, this increase in GLUT-4 protein could have contributed to enhancement of insulin action on glucose transport after chronic irbesartan treatment. This increase in muscle GLUT-4 protein after chronic Ang II receptor antagonism is consistent with the concept that Ang II may function as a negative modulator of GLUT-4 gene expression in these tissues, in parallel with its known effects on gene expression and cellular phenotypic alterations in the vascular endothelium, smooth muscle cells, and cardiac myocytes.32
We have observed that chronic administration of the ACE inhibitor trandolapril can induce small (25% to 30%) increases in GLUT-4 protein expression in skeletal muscle of the obese Zucker rat.8,10 This induction of GLUT-4 protein in insulin-resistant rat skeletal muscle could not be reproduced with chronic administration of bradykinin,33 the level of which is increased by ACE inhibitors.6 However, the present findings support the hypothesis that the ability of the ACE inhibitor trandolapril to enhance GLUT-4 protein expression in muscle of the obese Zucker rat may be reliant on the ability of this compound to effectively diminish formation and action of Ang II.
Chronic administration of ACE inhibitors to obese Zucker rats results in a significant diminution of the elevated level of fasting plasma free fatty acids,810 and this decrease in free fatty acids may be mechanistically linked to the improvement in insulin action on skeletal-muscle glucose transport.34 Interestingly, a lowering of plasma free fatty acids can be achieved with chronic administration of bradykinin33 but not with chronic administration of an Ang II receptor antagonist (Table). These findings are consistent with the interpretation that the lipid-lowering effects of ACE inhibitors are mediated by an enhancement of bradykinin action and not by a reduction in Ang II action. Furthermore, it is clear that the enhancement of insulin action brought about by chronic Ang II antagonism is not mediated by a reduction in the inhibitory effects of circulating free fatty acids.
Results of the present investigation are consistent with and complement the findings of Richey et al.23 These investigators demonstrated that acute infusion of Ang II into normal dogs during euglycemic, hyperinsulinemic clamp led to a significant decrease in insulin sensitivity and that this Ang II-induced insulin resistance probably developed because of direct inhibition of glucose transport by the myocyte. Our findings that the acute administration of irbesartan, which would prevent any negative action of Ang II on cellular glucose transport, led to an enhancement of insulin-stimulated skeletal-muscle glucose transport (at least in type I muscle), is entirely consistent with this hypothesis. What remains to be determined is the exact cellular mechanism for this deleterious effect of Ang II on insulin action. Acute administration of Ang II is known to cause inhibition of insulin-stimulated phosphatidylinositol-3-kinase activity in rat heart.35 However, whether this mechanism for Ang II-induced impairment of insulin signaling is functional in skeletal muscle and whether the antagonism of Ang II receptors removes this inhibitory effect of Ang II in insulin-resistant skeletal muscle of the obese Zucker rat are presently unknown.
In summary, the present investigation has demonstrated that acute administration of irbesartan, a specific Ang II (AT1-subtype) receptor antagonist, to the insulin-resistant obese Zucker rat induces dose-dependent improvement of whole-body insulin sensitivity, at least in part because of an enhancement of glucose transport in type I skeletal muscle. Moreover, chronic administration of irbesartan elicited an even greater improvement in whole-body insulin sensitivity, which was associated with increased glucose transport in both type I and type IIb skeletal muscles. This chronic Ang II receptor antagonism also elicited significant increases in GLUT-4 protein expression in skeletal muscle and myocardium. The results support the use of Ang II receptor antagonists to treat the hypertension and insulin resistance of skeletal-muscle glucose metabolism associated with insulin-resistance syndrome.
| Acknowledgments |
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Received February 2, 2000; first decision March 7, 2001; accepted April 12, 2001.
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D. S. Edgerton, K. M. Stettler, D. W. Neal, M. Scott, L. Bowen, W. Wilson, C. H. Hobbs, C. Leach, T. R. Strack, and A. D. Cherrington Inhalation of Human Insulin Is Associated with Improved Insulin Action Compared with Subcutaneous Injection and Endogenous Secretion in Dogs J. Pharmacol. Exp. Ther., December 1, 2006; 319(3): 1258 - 1264. [Abstract] [Full Text] [PDF] |
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M. Iwai, H.-S. Li, R. Chen, T. Shiuchi, L. Wu, L.-J. Min, J.-M. Li, M. Tsuda, J. Suzuki, Y. Tomono, et al. Calcium Channel Blocker Azelnidipine Reduces Glucose Intolerance in Diabetic Mice via Different Mechanism Than Angiotensin Receptor Blocker Olmesartan J. Pharmacol. Exp. Ther., December 1, 2006; 319(3): 1081 - 1087. [Abstract] [Full Text] [PDF] |
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D. S. Edgerton, A. D. Cherrington, P. Williams, D. W. Neal, M. Scott, L. Bowen, W. Wilson, C. H. Hobbs, C. Leach, M.-c. Kuo, et al. Inhalation of Human Insulin (Exubera) Augments the Efficiency of Muscle Glucose Uptake In Vivo Diabetes, December 1, 2006; 55(12): 3604 - 3610. [Abstract] [Full Text] [PDF] |
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Y. Wei, J. R. Sowers, R. Nistala, H. Gong, G. M.-E. Uptergrove, S. E. Clark, E. M. Morris, N. Szary, C. Manrique, and C. S. Stump Angiotensin II-induced NADPH Oxidase Activation Impairs Insulin Signaling in Skeletal Muscle Cells J. Biol. Chem., November 17, 2006; 281(46): 35137 - 35146. [Abstract] [Full Text] [PDF] |
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T. Kobayashi, Y. Hayashi, K. Taguchi, T. Matsumoto, and K. Kamata ANG II enhances contractile responses via PI3-kinase p110{delta} pathway in aortas from diabetic rats with systemic hyperinsulinemia Am J Physiol Heart Circ Physiol, August 1, 2006; 291(2): H846 - H853. [Abstract] [Full Text] [PDF] |
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C. S. Stump, M. T. Hamilton, and J. R. Sowers Effect of Antihypertensive Agents on the Development of Type 2 Diabetes Mellitus Mayo Clin. Proc., June 1, 2006; 81(6): 796 - 806. [Abstract] [Full Text] [PDF] |
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T. S. Hermann, W. Li, H. Dominguez, N. Ihlemann, C. Rask-Madsen, A. Major-Pedersen, D. B. Nielsen, K. W. Hansen, M. Hawkins, L. Kober, et al. Quinapril Treatment Increases Insulin-Stimulated Endothelial Function and Adiponectin Gene Expression in Patients with Type 2 Diabetes J. Clin. Endocrinol. Metab., March 1, 2006; 91(3): 1001 - 1008. [Abstract] [Full Text] [PDF] |
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S. O. Kasper, C. S. Carter, C. M. Ferrario, D. Ganten, L. F. Ferder, W. E. Sonntag, P. E. Gallagher, and D. I. Diz Growth, metabolism, and blood pressure disturbances during aging in transgenic rats with altered brain renin-angiotensin systems Physiol Genomics, November 17, 2005; 23(3): 311 - 317. [Abstract] [Full Text] [PDF] |
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C. S. Carter, G. Onder, S. B. Kritchevsky, and M. Pahor Angiotensin-Converting Enzyme Inhibition Intervention in Elderly Persons: Effects on Body Composition and Physical Performance J. Gerontol. A Biol. Sci. Med. Sci., November 1, 2005; 60(11): 1437 - 1446. [Abstract] [Full Text] [PDF] |
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R. Kouyama, T. Suganami, J. Nishida, M. Tanaka, T. Toyoda, M. Kiso, T. Chiwata, Y. Miyamoto, Y. Yoshimasa, A. Fukamizu, et al. Attenuation of Diet-Induced Weight Gain and Adiposity through Increased Energy Expenditure in Mice Lacking Angiotensin II Type 1a Receptor Endocrinology, August 1, 2005; 146(8): 3481 - 3489. [Abstract] [Full Text] [PDF] |
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A. M. Lemieux, C. J. Diehl, J. A. Sloniger, and E. J. Henriksen Voluntary exercise training enhances glucose transport but not insulin signaling capacity in muscle of hypertensive TG(mREN2)27 rats J Appl Physiol, July 1, 2005; 99(1): 357 - 362. [Abstract] [Full Text] [PDF] |
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R. Clasen, M. Schupp, A. Foryst-Ludwig, C. Sprang, M. Clemenz, M. Krikov, C. Thone-Reineke, T. Unger, and U. Kintscher PPAR{gamma}-Activating Angiotensin Type-1 Receptor Blockers Induce Adiponectin Hypertension, July 1, 2005; 46(1): 137 - 143. [Abstract] [Full Text] [PDF] |
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Y. Taniyama, H. Hitomi, A. Shah, R. W. Alexander, and K. K. Griendling Mechanisms of Reactive Oxygen Species-Dependent Downregulation of Insulin Receptor Substrate-1 by Angiotensin II Arterioscler Thromb Vasc Biol, June 1, 2005; 25(6): 1142 - 1147. [Abstract] [Full Text] [PDF] |
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Y. Miura, N. Yamamoto, S. Tsunekawa, S. Taguchi, Y. Eguchi, N. Ozaki, and Y. Oiso Replacement of Valsartan and Candesartan by Telmisartan in Hypertensive Patients With Type 2 Diabetes: Metabolic and antiatherogenic consequences Diabetes Care, March 1, 2005; 28(3): 757 - 758. [Full Text] [PDF] |
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M. C. Blendea, D. Jacobs, C. S. Stump, S. I. McFarlane, C. Ogrin, G. Bahtyiar, S. Stas, P. Kumar, Q. Sha, C. M. Ferrario, et al. Abrogation of oxidative stress improves insulin sensitivity in the Ren-2 rat model of tissue angiotensin II overexpression Am J Physiol Endocrinol Metab, February 1, 2005; 288(2): E353 - E359. [Abstract] [Full Text] [PDF] |
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F. A. El-Atat, S. N. Stas, S. I. McFarlane, and J. R. Sowers The Relationship between Hyperinsulinemia, Hypertension and Progressive Renal Disease J. Am. Soc. Nephrol., November 1, 2004; 15(11): 2816 - 2827. [Abstract] [Full Text] [PDF] |
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M. B. Marrero, D. Fulton, D. Stepp, and D. M. Stern Angiotensin II-Induced Insulin Resistance and Protein Tyrosine Phosphatases Arterioscler Thromb Vasc Biol, November 1, 2004; 24(11): 2009 - 2013. [Abstract] [Full Text] [PDF] |
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J. Ran, T. Hirano, and M. Adachi Chronic ANG II infusion increases plasma triglyceride level by stimulating hepatic triglyceride production in rats Am J Physiol Endocrinol Metab, November 1, 2004; 287(5): E955 - E961. [Abstract] [Full Text] [PDF] |
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J. Ran, T. Hirano, and M. Adachi Angiotensin II type 1 receptor blocker ameliorates overproduction and accumulation of triglyceride in the liver of Zucker fatty rats Am J Physiol Endocrinol Metab, August 1, 2004; 287(2): E227 - E232. [Abstract] [Full Text] [PDF] |
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F. Andreozzi, E. Laratta, A. Sciacqua, F. Perticone, and G. Sesti Angiotensin II Impairs the Insulin Signaling Pathway Promoting Production of Nitric Oxide by Inducing Phosphorylation of Insulin Receptor Substrate-1 on Ser312 and Ser616 in Human Umbilical Vein Endothelial Cells Circ. Res., May 14, 2004; 94(9): 1211 - 1218. [Abstract] [Full Text] [PDF] |
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M. Schupp, J. Janke, R. Clasen, T. Unger, and U. Kintscher Angiotensin Type 1 Receptor Blockers Induce Peroxisome Proliferator-Activated Receptor-{gamma} Activity Circulation, May 4, 2004; 109(17): 2054 - 2057. [Abstract] [Full Text] [PDF] |
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C. S. Carter, M. Cesari, W. T. Ambrosius, N. Hu, D. Diz, S. Oden, W. E. Sonntag, and M. Pahor Angiotensin-Converting Enzyme Inhibition, Body Composition, and Physical Performance in Aged Rats J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2004; 59(5): B416 - B423. [Abstract] [Full Text] [PDF] |
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J. R. Sowers Insulin resistance and hypertension Am J Physiol Heart Circ Physiol, May 1, 2004; 286(5): H1597 - H1602. [Abstract] [Full Text] [PDF] |
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S. C. Benson, H. A. Pershadsingh, C. I. Ho, A. Chittiboyina, P. Desai, M. Pravenec, N. Qi, J. Wang, M. A. Avery, and T. W. Kurtz Identification of Telmisartan as a Unique Angiotensin II Receptor Antagonist With Selective PPAR{gamma}-Modulating Activity Hypertension, May 1, 2004; 43(5): 993 - 1002. [Abstract] [Full Text] [PDF] |
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T. Shiuchi, M. Iwai, H.-S. Li, L. Wu, L.-J. Min, J.-M. Li, M. Okumura, T.-X. Cui, and M. Horiuchi Angiotensin II Type-1 Receptor Blocker Valsartan Enhances Insulin Sensitivity in Skeletal Muscles of Diabetic Mice Hypertension, May 1, 2004; 43(5): 1003 - 1010. [Abstract] [Full Text] [PDF] |
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C. Tikellis, P. J. Wookey, R. Candido, S. Andrikopoulos, M. C. Thomas, and M. E. Cooper Improved Islet Morphology after Blockade of the Renin- Angiotensin System in the ZDF Rat Diabetes, April 1, 2004; 53(4): 989 - 997. [Abstract] [Full Text] [PDF] |
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K. Shinozaki, K. Ayajiki, Y. Nishio, T. Sugaya, A. Kashiwagi, and T. Okamura Evidence for a Causal Role of the Renin-Angiotensin System in Vascular Dysfunction Associated With Insulin Resistance Hypertension, February 1, 2004; 43(2): 255 - 262. [Abstract] [Full Text] [PDF] |
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C.-H. Wang, N. Leung, N. Lapointe, L. Szeto, K. D. Uffelman, A. Giacca, J. L. Rouleau, and G. F. Lewis Vasopeptidase Inhibitor Omapatrilat Induces Profound Insulin Sensitization and Increases Myocardial Glucose Uptake in Zucker Fatty Rats: Studies Comparing a Vasopeptidase Inhibitor, Angiotensin-Converting Enzyme Inhibitor, and Angiotensin II Type I Receptor Blocker Circulation, April 15, 2003; 107(14): 1923 - 1929. [Abstract] [Full Text] [PDF] |
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E. D. Motley, K. Eguchi, C. Gardner, A. L. Hicks, C. M. Reynolds, G. D. Frank, M. Mifune, M. Ohba, and S. Eguchi Insulin-Induced Akt Activation Is Inhibited by Angiotensin II in the Vasculature Through Protein Kinase C-{alpha} Hypertension, March 1, 2003; 41(3): 775 - 780. [Abstract] [Full Text] [PDF] |
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T. Ogihara, T. Asano, K. Ando, Y. Chiba, H. Sakoda, M. Anai, N. Shojima, H. Ono, Y. Onishi, M. Fujishiro, et al. Angiotensin II-Induced Insulin Resistance Is Associated With Enhanced Insulin Signaling Hypertension, December 1, 2002; 40(6): 872 - 879. [Abstract] [Full Text] [PDF] |
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S. Jesmin, Y. Hattori, I. Sakuma, C. N. Mowa, and A. Kitabatake Role of ANG II in coronary capillary angiogenesis at the insulin-resistant stage of a NIDDM rat model Am J Physiol Heart Circ Physiol, October 1, 2002; 283 (4): H1387 - H1397. [Abstract] [Full Text] [PDF] |
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T. R. Kinnick, E. B. Youngblood, M. P. O'Keefe, V. Saengsirisuwan, M. K. Teachey, and E. J. Henriksen Exercise Effects on Muscle Insulin Signaling and Action: Selected Contribution: Modulation of insulin resistance and hypertension by voluntary exercise training in the TG(mREN2)27 rat J Appl Physiol, August 1, 2002; 93(2): 805 - 812. [Abstract] [Full Text] [PDF] |
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