The Preventive Effects of 8 Weeks of Resistance Training on Glucose Tolerance and Muscle Fiber Type Composition in Zucker Rats.
10.4093/dmj.2015.39.5.424
- Author:
Ji Yeon KIM
1
;
Mi Jung CHOI
;
Byunghun SO
;
Hee Jae KIM
;
Je Kyung SEONG
;
Wook SONG
Author Information
1. Health and Exercise Science Laboratory, Institute of Sports Science, Seoul National University College of Education, Seoul, Korea. songw3@snu.ac.kr
- Publication Type:Original Article
- Keywords:
Diabetes mellitus, type 2;
Glucose tolerance;
Muscle fiber type;
Rats, Zucker;
Resistance training
- MeSH:
Animals;
Blotting, Western;
Diabetes Mellitus, Type 2;
Fasting;
Fluorescent Antibody Technique;
Glucose Tolerance Test;
Glucose Transport Proteins, Facilitative;
Glucose*;
Hand Strength;
Humans;
Immunohistochemistry;
Male;
Myosin Heavy Chains;
Rats;
Rats, Zucker*;
Resistance Training*
- From:Diabetes & Metabolism Journal
2015;39(5):424-433
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: We investigated the therapeutic effects of resistance training on Zucker rats before and after the onset of diabetes to understand the importance of the timing of exercise intervention. We assessed whether 8 weeks of resistance training ameliorated impaired glucose tolerance and altered muscle fiber type composition in Zucker rats. METHODS: Five-week-old male Zucker rats were divided into Zucker lean control (ZLC-Con), non-exercised Zucker diabetic fatty (ZDF-Con), and exercised Zucker diabetic fatty (ZDF-Ex) groups. The ZDF-Ex rats climbed a ladder three times a week for 8 weeks. Intraperitoneal glucose tolerance tests (IPGTT) were performed on the 1st and 8th weeks of training, and grip strength was measured during the last week. We also measured glucose transporter 4 (GLUT4) expression by Western blot and immunofluorescence. Moreover, immunohistochemistry was performed to assess muscle fiber type composition. RESULTS: Fasting glucose levels and area under the curve responses to IPGTTs gradually increased as diabetes progressed in the ZDF-Con rats but decreased in the ZDF-Ex rats. Grip strength decreased in the ZDF-Con rats. However, resistance training did not improve grip strength in the ZDF-Ex rats. GLUT4 expression in the ZLC-Con and the ZDF-Con rats did not differ, but it increased in the ZDF-Ex rats. The proportions of myosin heavy chain I and II were lower and higher, respectively, in the ZDF-Con rats compared to the ZLC-Con rats. Muscle fiber type composition did not change in the ZDF-Ex rats. CONCLUSION: Our results suggest that regular resistance training initiated at the onset of diabetes can improve glucose tolerance and GLUT4 expression without changing muscle morphology in Zucker rats.
