تأثير شدت‌ تمرين ورزشي بر ظرفيت نوزايي قلبي در رت‌هاي مبتلا به آنفاركتوس ميوكارد

The Effect of Exercise Training Intensity on Cardiac Regeneration Capacity in Rats with Myocardial Infarction

ﻫﺪف از ﭘﮋوﻫﺶ ﺣﺎﺿﺮ، ﺑﺮرﺳﯽ ﺗﺄﺛﯿﺮ ﺷﺪت ﺗﻤﺮﯾﻦ ورزﺷﯽ ﺑﺮ ﻇﺮﻓﯿﺖ ﻧﻮزاﯾﯽ ﻗﻠﺒﯽ در رتﻫﺎي ﻣﺒﺘﻼ ﺑﻪ آﻧﻔﺎرﮐﺘﻮس ﻣﯿﻮﮐﺎرد )MI( ﺑﻮد. ﺑﻪ اﯾﻦ ﻣﻨﻈﻮر، اﺑﺘﺪا رتﻫﺎي ﻧﺮ ﻧﮋاد وﯾﺴﺘﺎر ﺗﺤﺖ ﻋﻤﻞ ﺟﺮاﺣﯽ ﺑﺴﺘﻦ ﺷﺮﯾﺎن ﮐﺮوﻧﺮي LAD ﻗﺮار ﮔﺮﻓﺘﻨﺪ و ﺳﭙﺲ از ﻃﺮﯾﻖ اﮐﻮﮐﺎردﯾﻮﮔﺮاﻓﯽ اﯾﺠﺎد MI ﺗﺄﯾﯿﺪ ﺷﺪ. ﭼﻬﺎر ﻫﻔﺘﻪ ﭘﺲ از ﺟﺮاﺣﯽ، رتﻫﺎي ﻣﺒﺘﻼ ﺑﻪ MI ﺑﻪﺻﻮرت ﺗﺼﺎدﻓﯽ در ﮔﺮوهﻫﺎي ﺗﻤﺮﯾﻦ ورزﺷﯽ ﺑﺎ ﺷﺪتﻫﺎي ﮐﻢ )LIT(، ﻣﺘﻮﺳﻂ )MIT(، ﺑﺎﻻ )HIT( و ﺷﻢ )Sham( ﺑﻪ اﺿﺎﻓﮥ ﮔﺮوه ﮐﻨﺘﺮل ﺳﺎﻟﻢ )Con( ﻗﺮار ﮔﺮﻓﺘﻨﺪ و ﭘﺮوﺗﮑﻞﻫﺎي ﺗﻤﺮﯾﻦ ورزﺷﯽ را ﺑﻪ ﻣﺪت 6 ﻫﻔﺘﻪ و 5 ﺟﻠﺴﻪ در ﻫﻔﺘﻪ اﺟﺮا ﮐﺮدﻧﺪ. ﭘﺲ از اﺗﻤﺎم ﻣﺪاﺧﻠﮥ ﺗﻤﺮﯾﻦ ورزﺷﯽ رتﻫﺎ ﺗﺸﺮﯾﺢ ﺷﺪه و دادهﻫﺎي ﺣﺎﺻﻞ از ﻃﺮﯾﻖ آزﻣﻮن ANOVA ﯾﮑﻄﺮﻓﻪ و آزﻣﻮن LSD ﺗﺠﺰﯾﻪوﺗﺤﻠﯿﻞ ﺷﺪﻧﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﯿﻦ ﮔﺮوهﻫﺎ در ﻣﻘﺎدﯾﺮ ﮐﺴﺮ ﺗﺰرﯾﻘﯽ، ﮐﺴﺮ ﮐﻮﺗﺎهﺷﺪﮔﯽ، mRNA Gata4 و mRNA Tbx5 ﺗﻔﺎوت ﻣﻌﻨﺎداري وﺟﻮد دارد )0/001=P(. ﻧﺘﺎﯾﺞ آزﻣﻮن ﺗﻌﻘﯿﺒﯽ ﻧﺸﺎن داد در ﻫﺮ ﺳﻪ ﮔﺮوه ﺗﻤﺮﯾﻦ ورزﺷﯽ ﻣﻘﺎدﯾﺮ ﮐﺴﺮ ﺗﺰرﯾﻘﯽ و ﮐﺴﺮ ﮐﻮﺗﺎهﺷﺪﮔﯽ ﻧﺴﺒﺖ ﺑﻪ ﮔﺮوه Sham اﻓﺰاﯾﺶ ﻣﻌﻨﺎداري داﺷﺘﻪاﻧﺪ، اﻣﺎ ﺑﺎ وﺟﻮد اﯾﻦ اﻓﺰاﯾﺶ، ﻣﻘﺎدﯾﺮ آﻧﻬﺎ در ﮔﺮوه Con ﺑﻪ ﺷﮑﻞ ﻣﻌﻨﺎداري ﺑﯿﺸﺘﺮ از ﮔﺮوهﻫﺎي ﻣﺒﺘﻼ ﺑﻪ MI ﺑﻮد. ﻫﻤﭽﻨﯿﻦ در ﻣﻘﺎدﯾﺮ mRNA Gata4 ﮔﺮوه LIT ﻧﺴﺒﺖ ﺑﻪ ﮔﺮوهﻫﺎي Sham ،HIT ،MIT و Con اﻓﺰاﯾﺶ ﻣﻌﻨﺎداري ﻣﺸﺎﻫﺪه ﺷﺪ. ﺑﺎ وﺟﻮد اﯾﻦ، در ﻣﻘﺎدﯾﺮ mRNA Tbx5 ﺑﯿﻦ ﮔﺮوهﻫﺎي ﻣﺒﺘﻼ ﺑﻪ MI ﺗﻐﯿﯿﺮات ﻣﻌﻨﺎداري ﻣﺸﺎﻫﺪه ﻧﺸﺪ و ﺗﻨﻬﺎ ﻣﻘﺎدﯾﺮ mRNA Tbx5 در ﮔﺮوه Con ﻧﺴﺒﺖ ﺑﻪ ﮔﺮوهﻫﺎي ﻣﺒﺘﻼ ﺑﻪ MI ﺑﻪﺻﻮرت ﻣﻌﻨﺎداري ﺑﯿﺸﺘﺮ اﺳﺖ. در ﻧﺘﯿﺠﻪ، ﺗﻤﺮﯾﻦ ورزﺷﯽ ﺻﺮفﻧﻈﺮ از ﺷﺪت، ﻋﻤﻠﮑﺮد ﻗﻠﺒﯽ رتﻫﺎي ﻣﺒﺘﻼ ﺑﻪ MI را اﻓﺰاﯾﺶ ﻣﯽدﻫﺪ، اﻣﺎ ﺑﻪﻧﻈﺮ ﻣﯽرﺳﺪ ﺗﻤﺮﯾﻦ ورزﺷﯽ ﺑﺎ ﺷﺪت ﮐﻢ، ﻋﺎﻣﻞ ﻣﺆﺛﺮﺗﺮي در اﻓﺰاﯾﺶ ﻇﺮﻓﯿﺖ ﻧﻮزاﯾﯽ ﻗﻠﺒﯽ رتﻫﺎي ﻣﺒﺘﻼ ﺑﻪ MI ﺑﺎﺷﺪ.

The aim of this study was to investigate the effect of exercise training intensity on cardiac regeneration capacity in rats with myocardial infarction (MI). Male wistar rats were exposed to LAD coronary artery ligation surgery and then the creation of MI was confirmed by echocardiography. Four weeks after surgery, the rats with MI were randomly assigned to these groups: low intensity training (LIT), moderate intensity training (MIT), high intensity training (HIT), and Sham, plus a healthy control group (Con). Training groups performed the exercise training protocols for 6 weeks, 5 sessions per week. The rats were sacrificed after the exercise training intervention, and the obtained data were analyzed by one-way ANOVA and LSD test. The results showed a significant difference in the values of ejection fraction, fractional shortening, mRNA Gata4, and mRNA Tbx5 among all groups (P=0.001). LSD test results demonstrated that ejection fraction and fractional shortening values increased significantly in all three exercise training groups compared with the sham group. However, contrary to this increase, their values in the Con group was significantly higher than the groups with MI. Results also showed that mRNA Gata4 value significantly increased in the LIT group compared with the MIT, HIT, Sham, and Con groups. However, mRNA Tbx5 values showed no significant changes among the groups with MI. Only mRNA Tbx5 values in Con group were significantly higher compared with the groups with MI. In conclusion, regardless the intensity, exercise training increases cardiovascular function in rats with MI. However, it seems that low intensity exercise is a more effective agent in increasing cardiac regeneration capacity in rats with MI.