Razi Journal of Medical Sciences

fa مقایسه دو مدل تمرین تناوبی شدید بر مقادیر گلوکز و بیان ژن های Bax و Bcl-2 در کاردیومایوسیت رت های دیابتی Comparison of two types of high intensity interval training on glucose levels and genes expression of Bax and Bcl-2 in cardiomyocytes of diabetic rats فیزیولوژی ورزش Exercise Physiology پژوهشي Research زمینه و هدف: اختلالات قلبی حاصل از افزایش آﭘﻮﭘﺘﻮز یکی از مهم‌ترین عوارض ناشی از دیابت است که تحت تاثیر دزهای  مختلف تمرین تناوبی شدید قرار می‌گیرد. هدف از مطالعه حاضر مقایسه دو شیوه تمرین تناوبی شدید بر مقادیر گلوکز و بیان ژن‌های  Bax و Bcl-2 در کاردیومایوسیت رت‌های دیابتی بود. روش کار: در مطالعه تجربی حاضر، 24 سر رت نر نژاد ویستار هشت هفته‌ایی، با میانگین وزن 18±321 گرم پس از القاء دیابت بوسیله STZ به طور تصادفی به 4 گروه کنترل سالم (NC)، کنترل دیابتی (DC)، گروه تمرین تناوبی شدید نوع یک (HIIT1:1) و گروه تمرین تناوبی شدید نوع دو (HIIT2:1) تقسیم شدند. سپس گروه‌های تمرینی 5 روز در هفته به مدت 4 هفته با دزهای  متفاوت، اما مسافت یکسان تمرین کردند. تجزیه و تحلیل آماری داده ها توسط تحلیل واریانس یک‌سویه در سطح معناداری 05/0 انجام گرفت. یافته‌ها: مداخله HIIT2:1 باعث کاهش معنادار مقادیر گلوکز و بیان Bax (001/0p<) و افزایش معنادار Bcl-2 در کاردیومایوسیت‌ها نسبت به کنترل دیابتی شد  (01/0p<). HIIT1:1 تنها باعث کاهش معنادار مقادیر گلوکز نسبت به گروه DC شد (05/0p<). علاوه بر این، بیان ژن Bax کاردیومایوسیت‌ها در گروه HIIT2:1 به شکل معناداری کمتر از گروه HIIT1:1 بود (05/0p<). نتیجه‌گیری: تمرین HIIT2:1 عوارض مخرب قلبی ناشی از  دیابت را به حداقل می‌رساند. علاوه بر این، دز تجویزی تمرین HIIT در این تغییرات مکانیزمی مهم و تاثیرگذار است.   Background & Aims: Following to advent of obesity, Type-II diabetes has been converted into a pandemic disease during the recent decades and it has been introduced as one of the main reasons for mortality throughout the world more than ever. Hyperglycemia and rising glucose caused by diabetes is led to increase apoptosis in cardiomyocytes at left ventricle. Bax-gene is one of the key genes at this process in controlling start point of apoptotic process and Bc1-2 gene also inhibits apoptosis. Accordingly, researchers have always acknowledged that exercise training including HIIT may play protective role for heart against diabetic side-effects by reducing quantities of glucose and apoptosis in cardiac cells. Thus, the present study aimed to compare two HIIT methods concerning quantities of glucose and expression of apoptotic and anti-apoptotic Bax and Bcl-2 genes in cardiomyocytes of rats with type II diabetes. Methods: In the current experimental study, 24 rats of Vistar species (8 weeks) and average weight (321±18g) were divided randomly into four groups of Normal Control (NC), Diabetic Control (DC), High Intensity Interval Training Type I (HIIT1:1) and High Intensity Interval Training Type II (HIIT2:1) after adaption to the environment for one week and familiarity with treadmill. Diabetes was induced to all groups, except Normal Control (NC) group, using Streptozotocin (STZ) and Nicotine Amide. Then, the trained groups exercised with different doses, but in identical distance 5 days a week for 4 weeks. The speed of reaching to the maximum consumed oxygen dosage (vVO2max) was measured at the sixth day once in both weeks. HIIT1:1 Protocol: Warm up and cool down for three minutes by intensity of (vVO2max= 40%); high intensity (Frequency= 2min); first week: vVO2max= 80% (Four times); second week: vVO2max= 85% (Four times); third and fourth weeks: vVO2max= 90% (Five times); low intensity (2min); vVO2max= 40% (Four times at first and second weeks and five times at third and fourth weeks). HIIT2:1 Protocol: Warm up and cool down for three minutes by intensity of vVO2max= 30%; high intensity (Frequency= 2min); First week: vVO2max= 80% (Five times); second week: vVO2max= 85% (Five times); third and fourth weeks: vVO2max= 90% (Seven times), low intensity (1min); vVO2max= 30% (5 times at first and second weeks and seven times at third and fourth weeks). Rats were anesthetized by inter-peritoneal infusion of Ketamine (90mg/kg) and Xylazine (10mg/kg) 24h after the last training session. The blood sample was collected directly from hearts of rats and plasma isolation was done by centrifuging at 15°C at 3000RPM for 15min. afterward, left ventricle was extracted immediately and frozen in nitrogen (-20°C) and stored in freezer (-80°C) to measure gene expression. QRT-PCR technique was utilized to analyze variance of Bax- and Bcl-2 genes expression. To conduct statistical data analysis, normality of data was primarily examined using Shapiro-Wilcox test. Given insignificance of this test (p>0.05), One-Way ANOVA statistical test was employed for determining difference between studied groups. Then, Tukey ad hoc test was used (Sig = 0.05) in order to determine significance position. Microsoft Excel-2007 software was utilized for drawing diagrams. All statistical tests were conducted by means of SPSS statistical software (v.21). Results: Variance of weight quantities was not significant after 4 weeks, but variance of glucose showed significance increase in all three groups (DC, HIIT1:1 and HIIT2:1 groups) compared to Normal Control (NC) group (p<0.005). Similarly, glucose quantities were reduced significantly in both trained groups versus DC group after four weeks (p<0.001). The results of one-way ANOVA indicated significant difference in Bax-gene expression between studied groups (p<0.05). The results of intergroup analysis derived from Tukey’s test showed that significant increase was observed in Bax-gene expression at DC group compared to HIIT2:1 (p<0.001) and NC (p<0.001) groups. Likewise, significant difference was seen in terms of gene expression of this variable between two trained models (p=0.038) so that further reduction and significance was observed in HIIT2:1 group. Similarly, results of one-way ANOVA suggest existing significant difference in Bcl-2 gene expression between groups (p<0.001). The results of intergroup analysis derived from Tukey’s test indicated significant reduction in Bcl-2 gene expression at DC group versus HIIT2:1 (p=0.005) and Normal Control (p<0.001) groups. Similarly, no significant difference was seen between two trained model in terms of gene expression in his variable (p=0.079). Conclusion: The results of current study indicated that diabetic induction might increase glucose quantities, Bax-gene expression and reduce Bcl-2 gene expression in cardiomyocytes at all groups (HIIT1:1, HIIT2:1 and DC groups) versus Normal Control (NC) group. Likewise, both training interventions (HIIT1:1 and HIIT2:1) reduced significantly glucose quantities in cardiomyocytes compared to DC group. In addition, HIIT2:1 training intervention significantly inhibited apoptosis-inducing of Bax gene expression and induced significantly anti-apoptosis of Bcl-2 gene expression in cardiomyocytes of rats with diabetes compared to DC group while this variance was not significant in cardiomyocytes of HIIT1:1 group versus DC group. Similarly, we showed that Bax-gene expressions were significantly reduced in cardiomyocytes of HIIT2:1 group compared to HIIT1:1 group. The findings of current study may indicate importance of different effect of various frequencies of exercise on apoptotic mechanisms of cardiomyocytes at rats with type-II diabetes. These findings showed that various HIIT frequencies might be followed with different impacts and even noticeable differences in glucose absorption in cardiomyocytes at left ventricle and response of apoptotic variable in cardiac muscle so that more tangible and beneficial mechanism variance was observed in cardiac muscle at rats in HIIT2:1 group toward inhibition of cardiac disorders. In other words, we identified that further high intensity and shorter time frequency at lower intensity in HIIT2:1 versus HIIT1:1 group might doubly affect variance of glucose quantities absorbed by cardiac muscular cells and apoptosis mechanism in cardiomyocytes while both trained groups had passed through the same distance. The more efficiently increase in glucose quantities and subsequently more optimal reduction in apoptosis process by Bax/Bcl-2 axis signifies better and more beneficial effect in this training model. Therefore, these findings not only suggest further studies for analysis of most efficient and profitable HIIT model in patients with type-II diabetes, but also this exercise training model with shorter time and higher intensity than other models could be proposed as a potential therapeutic strategy in the clinical centers relating to type-II diabetes for cardiomyopathy prophylaxis and improvement caused by diabetes.   آپوپتوز, دیابت نوع2, تمرین تناوبی شدید,Bax,Bcl-2 Apoptosis, Type II Diabetes, High Intensity Interval Training (HIIT), Bax, Bcl-2 52 62 http://rjms.iums.ac.ir/browse.php?a_code=A-10-4986-1&slc_lang=fa&sid=1 Hamid Kia حمید کیا hamidkia12@gmail.com 3900319475328460056249 3900319475328460056249 No Islamic Azad University, Central Tehran Branch, Tehran, Iran دانشگاه آزاد اسلامی واحد تهران مرکزی، تهران، ایران Maghsoud Peeri مقصود پیری m.peeri@iauctb.ac.ir 3900319475328460056250 3900319475328460056250 Yes Islamic Azad University, Tehran, Iran دانشگاه آزاد اسلامی، تهران، ایران Maryam Delfan مریم دلفان marydelfan@gmail.com 3900319475328460056251 3900319475328460056251 No Department of Exercise Physiology, Faculty of Sport Sciences, Alzahra University,Tehran, Iran دانشکده تربیت بدنی و علوم ورزشی، دانشگاه الزهرا، تهران، ایران