Razi Journal of Medical Sciences

fa اثر تمرینات هوازی بر بیان ناقل 4 گلوکز (GLUT4) در عضله دوقلو و گلوکز خون در رت های دیابتی (نوع 2) شده با نیکوتین آمید و STZ The effect of aerobic training on Glucose transporter type 4 expression in Gastrocnemius muscle and blood glucose of type 2 diabetes rats induced by Nicotinamide and STZ فیزیولوژی ورزش Exercise Physiology پژوهشي Research زمینه و هدف: انتقال غشایی گلوکز از مهمترین تعیین کننده‌های هایپرگلیسیمی در دیابتی های نوع 2 است. مطالعه حاضر با هدف تعیین اثر تمرینات هوازی بر بیان ناقل 4 گلوکز (GLUT4) در عضله دوقلوی رت های دیابتی نوع 2 است. روش کار: 16 سر رت نر ویستار 10 هفته ای (20 ± 220 گرم) از طریق تزریق درون صفاقی نیکوتین آمید و استرپتوزوتوسین (STZ) دیابتی نوع 2 شدند و به شیوه تصادفی به گروه های ورزش هوازی (8 = n) و کنترل (8 = n) تقسیم شدند. گروه ورزش در یک دوره تمرینات هوازی 12 هفته ای به تعداد 5 جلسه در هفته در قالب دویدن روی تریدمیل شرکت نمودند. 48 ساعت پس از آخرین جلسه تمرینی، سطوح ناشتایی گلوکز و بیان GLUT4 در عضله دوقلو در دو گروه اندازه گیری شد. از آزمون آماری تی مستقل در سطح معنی داری کمتر از 5 درصد جهت مقایسه متغیرها بین گروه‌ها استفاده شد. یافته‌ها: در مقایسه با رت های گروه کنترل، سطوح گلوکز ناشتا در پاسخ به تمرینات هوازی به میزان معنی کاهش یافت    (001/0 = p). تمرینات هوازی همچنین به افزایش معنی دار بیان GLUT4 در عضله دوقلو نسبت به گروه کنترل منجر شد(029/0 = p). نتیجه‌گیری: بر پایه شواهد موجود، کاهش سطوح گلوکز در پاسخ به تمرینات هوازی در رت‌های دیابتی نوع 2 را می‌توان به افزایش بیان GLUT4 در عضله دوقلو نسبت داد. با این وجود، اجرای مطالعات بیشتر با هدف شناخت دیگر مکانیسم‌های موثر بر سطوح گلوکز در پاسخ به تمرینات ورزشی در رت‌های دیابتی مورد نیاز است. Background: In recent decades, the role of genetic factors in both secretion of insulin from the pancreas and insulin resistance in target tissues has got particular importance. Some genetic factors such as TCF7L2 and its polymorphisms or GLP-1 severely affect the synthesis and secretion of insulin from beta cells (2, 3). On the other hand, some other genetic components, such as FOXO1, PPARy, and FTO, also affect the energy homeostasis and metabolism of glucose and fat in target tissues such as skeletal muscles and fatty tissue. Membrane glucose transport is one of the most important determinants of hyperglycemia in type 2 diabetics. The purpose of this study was to determine the effect of aerobic training on the expression of 4-glucose transporter (GLUT4) in expression in gastrocnemius muscle in type 2 diabetic rats (T2D). Methods: In this experimental-applied study, eighteen 10-weeks-old male Wistar rats (220 ± 20 g), procured from the institutional animal house facility were used for all the experiments and after induction of T2D were randomly divided into exercise (aerobic training / 12 weeks, n = 8) and control (no training, n = 8) groups aimed to determine the effect of aerobic training on GLUT4 expression in gastrocnemius muscle. Sample size and the number of rats in each groups designed according to the same previous studies that assessed gene expression in diabetes rats in response to exercise training. Animals were maintained under standardized conditions (12-h light/dark cycle, 25 ± 2 °C & humidity 45-55 %). The rats were left for 1 week for acclimatization prior to the commencement of the experiment. The study was approved by department of Exercise physiology of Amirkabir University of Technology, Iran  and  carried  out  in  accordance  with  CPCSEA (Committee  for  the  Purpose  of  Control  and  Supervision  of Experiment on Animal) guidelines. T2D induced by STZ and Nicotinamide injection (dissolved in citrate buffer, pH 4.5). Hyperglycemia was confirmed by elevated blood glucose levels on day 7 after diabetes induction and only animals with fasting blood glucose level between 150-400 mg/dl were selected for were served as T2D rats and used in the study. The exercise group participated in a 12-week aerobic exercise (5 days/weekly) in the form of running on the treadmill. Finally, 48 hours after the lasted exercise session, the fasting rats in both groups (with 10-12 hours overnight fast) were anesthetized through intraperitoneal injection of 10% ketamine at a dose of 50 mg/kg along with 2% xylosine at a dose of 10 mg/kg, after which they were underwent dissection. After the rats were anesthetized, blood samples were collected through cardiac puncture. Then, subcutaneous fatty tissue was removed and immersed in RNA later until biochemical analysis was performed for determine GLUT4 expression. The blood samples were used to analyze the blood glucose and serum insulin. The serum was separated by centrifugation (5 min, 3,000 rpm) and was analyzed for glucose by glucose using a Cobas 6000 Analyzer (Roche, Germany). Glucose was determined by the oxidase method (Pars Azmoon kit, Tehran). The remaining serum samples were then stored at −20 ◦C until the insulin determination was made by ELISA method (Demeditec, Germany) and the intra- assay and inter-assay coefficient of variation of the method were 2.6% and 2.88 respectively. The RNA was extracted by Rneasy protect mini kit (QIAGEN) from subcutaneous fatty tissue according to manufactures instructions (19).  RT-Real time PCR quantification of FTO mRNA was performed with Rotor gene 6000 system using One Step SYBR PrimeScript RT PCR kit (Takara co.) according to manufactures instructions. Melting curve analysis was performed at the end of PCR cycles in order to validate the specificity of the expected PCR product. We used RNA Polymrasell as a normalizer. Data were analyzed by computer using the Statistical Package for Social Sciences (SPSS) for Windows, version 16.0. Normal distribution of data was analyzed by the Kolmogorov-Smirnov normality test. Independent student t test was used for comparison of variables between two groups. A p-value of less than 0.05 was considered to be statistically significant Results: Compare to control rats, Fasting glucose level decreased significant in response to aerobic training (p = 0.001). Aerobic training also resulted in significant increase in GLUT4 expression in Gastrocnemius muscle (p = 0.029). Conclusion: Based on the available evidence, a decrease in glucose levels in response to aerobic training in T2D rats can be attributed to an increase in GLUT4 expression in twin muscle. However, further studies are needed to identify other effective mechanisms on glucose levels in response to exercise training in diabetes rats.   بیان ژن, دیابت نوع 2, تمرین هوازی, هموستاز گلوکز Aerobic training, Glucose homeostasis, Gene expression, Type 2 diabetes 76 85 http://rjms.iums.ac.ir/browse.php?a_code=A-10-4727-1&slc_lang=fa&sid=1 Ashraf Amini اشرف امینی aminia2018@yahoo.com 3900319475328460052821 3900319475328460052821 Yes department of Physical Education and Sport Sciences, Amirkabir University of Technology, Tehran, Iran. دانشگاه صنعتی امیرکبیر، تهران، ایران zahra Mirakhori زهرا میراخوری zmirakhori@gmail.com 3900319475328460052822 3900319475328460052822 No department of Physical Education and Sport Sciences, Amirkabir University of Technology, Tehran, Iran. گروه تربیت بدنی و علوم ورزشی، دانشگاه صنعتی امیرکبیر، تهران، ایران Mojtaba Eizadi مجتبی ایزدی izadimojtaba2006@yahoo.com 3900319475328460052823 3900319475328460052823 No department of Exercise Physiology, Islamic Azad University, Saveh Branch, Saveh, Iran گروه فیزیولوژی ورزش، دانشگاه آزاد اسلامی واحد ساوه، ساوه، ایران