The role of resistance and aerobic exercise training on insulin sensitivity measures in STZ-induced Type 1 diabetic rodents Katharine E. Hall a , Matthew W. McDonald b , Kenneth N. Grisé b , Oscar A. Campos b , Earl G. Noble b , C.W. James Melling a, b, ⁎ a Health and Rehabilitation Sciences, University of Western Ontario, London, Ontario, Canada b School of Kinesiology, University of Western Ontario, London, Ontario, Canada ARTICLE INFO ABSTRACT Article history: Received 29 January 2013 Accepted 20 May 2013 Individuals with Type 1 Diabetes Mellitus (T1DM) can develop insulin resistance. Regular exercise may improve insulin resistance partially through increased expression of skeletal muscle GLUT4 content. Objective. To examine if different exercise training modalities can alter glucose tolerance through changes in skeletal muscle GLUT4 content in T1DM rats. Methods. Fifty rats were divided into 5 groups; control, diabetic control, diabetic resistance exercised, and diabetic high and low intensity treadmill exercised. Diabetes was induced using multiple low dose Streptozotocin (20 mg/kg/day) injections and blood glucose concentrations were maintained moderately hyperglycemic through subcutaneous insulin pellets. Resistance trained rats climbed a ladder with incremental loads, while treadmill trained rats ran on a treadmill at 27 or 15 m/min, respectively, all for 6 weeks. Results. At weeks 3 and 6, area under the curve measurements following an intravenous glucose tolerance test (AUC-IVGTT) in all diabetic groups were higher than control rats (p < 0.05). At 6 weeks, all exercise groups had significantly lower AUC-IVGTT values than diabetic control animals (p < 0.05). Treadmill trained rats had the lowest insulin dose requirement of the T1DM rats and the greatest reduction in insulin dosage was evident in high intensity treadmill exercise. Concomitant with improvements in glucose handling improvements, tissue-specific elevations in GLUT4 content were demonstrated in both red and white portions of vastus lateralis and gastrocnemius muscles, suggesting that glucose handling capacity was altered in the skeletal muscle of exercised T1DM rats. Conclusions. These results suggest that, while all exercise modalities can improve glucose tolerance, each mode leads to differential improvements in insulin requirements and protein content alterations. © 2013 Elsevier Inc. All rights reserved. Keywords: Insulin resistance Insulin dose GLUT4 protein content Resistance training Aerobic training METABOLISM CLINICAL AND EXPERIMENTAL XX (2013) XXX – XXX Abbreviation: ANOVA, Analysis of variance; AUC, Area under the curve; C, Non-diabetic sedentary control; CD, Diabetic sedentary control; CHD, Coronary heart disease; DH, Diabetic high intensity aerobic exercise; DL, Diabetic low intensity aerobic exercise; DR, Diabetic resistance exercise; GLUT4, Plasma membrane glucose transporter 4; HbA1 c , Hemoglobin A1 C ; HOMA, Homeostatic model assessment; IVGTT, Intravenous glucose tolerance test; RG, Red gastrocnemius; RV, Red vastus lateralis; STZ, Streptozotocin; TBS, Tris buffered saline; T1DM, Type 1 diabetes mellitus; T2DM, Type 2 diabetes mellitus; WG, White gastrocnemius; WV, White vastus lateralis. ⁎ Corresponding author. Arthur and Sonia Labatt Health Sciences Building, Room 218, University of Western Ontario, London, Ontario, Canada N6A 5B9. Fax: +1 519 850 2432. E-mail address: jmelling@uwo.ca (C.W.J. Melling). 0026-0495/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.metabol.2013.05.012 Available online at www.sciencedirect.com Metabolism www.metabolismjournal.com Please cite this article as: Hall KE, et al, The role of resistance and aerobic exercise training on insulin sensitivity measures in STZ-induced Type 1 diabetic rodents, Metabolism (2013), http://dx.doi.org/10.1016/j.metabol.2013.05.012