Author(s): TANG, C.Y., LAI, C., FU, S., TSAO, P., TSENG, K., Institution: UNIVERSITY OF TAIPEI, Country: TAIWAN, Abstract-ID: 1602

INTRODUCTION:
In recent years, High-Intensity Interval Training (HIIT) has gained popularity among athletes due to its ability to save exercise time, promote more efficient fat loss, and assist in improving disease prognosis. The results of this study will clarify whether HIIT can reduce myocardial damage caused by renal ischemia-reperfusion, with the aim of serving as a reference for exercise prescriptions in health promotion in the future.
METHODS:
30 male Sprague Dawley rats were divided into three groups: Sham (SHAM), Non-High-Intensity Interval Training (Non-HIIT), and High-Intensity Interval Training (HIIT). The SHAM group had no further intervention after abdominal opening, while the other two underwent 60 minutes of renal artery occlusion and 24 hours of reperfusion before being sacrificed. Blood samples were taken to assess Troponin-I and CPK levels, and ELISA measured serum TNF-α for apoptosis and inflammation. Heart tissues were also collected for HE and TUNEL staining to evaluate cardiac damage and myocardial apoptosis.
RESULTS:
Blood test results revealed significant differences among the groups. Troponin I levels were markedly different between SHAM, CAO, and HIIT groups: 0.68 ± 0.47 vs. 298.08 ± 173.09 vs. 41.56 ± 10.44 (p < 0.01). Similarly, CPK levels showed substantial variations: 577.50 ± 19.40 vs. 8531.33 ± 591.00 vs. 3918.17 ± 1761.22 (p < 0.001). In the Elisa assay, TNF-α concentrations differed significantly among the groups: SHAM vs. CAO vs. HIIT: 39.12 ± 5.59 vs. 104.408 ± 6.62 vs. 62.31 ± 6.57 (p < 0.001). Additionally, HE staining indicated notable differences in myocardial damage quantification: SHAM vs. CAO vs. HIIT: 0.20 ± 0.08 vs. 3.65 ± 0.44 vs. 1.28 ± 0.32 (p < 0.001). Finally, TUNEL analysis showed significant variations in myocardial cell apoptosis rates: SHAM vs. CAO vs. HIIT: 2.3 ± 0.7 vs. 34.3 ± 5.5 vs. 19.7 ± 1.2 (p < 0.01).
CONCLUSION:
Studies have shown that HIIT can significantly reduce plasma mRNA expression related to inflammation. It also helps lower Agt mRNA expression associated with the Renin-Angiotensin-Aldosterone System (RAAS), thus aiding in blood pressure reduction, and decreases Fan1 mRNA expression related to apoptosis, thereby preventing cell damage (1,2). Additionally, HIIT intervention has been found to reduce kidney weight and the ratio of kidney weight to body weight, indicating that this exercise modality can improve renal interstitial fibrosis, reduce kidney damage, and consequently mitigate myocardial damage (3). Our results demonstrate that four weeks of consecutive HIIT intervention before renal artery occlusion significantly reduces cardiac damage. From the perspective of primary and secondary disease prevention and treatment strategies, improving physical function through exercise represents one of the simplest and most cost-effective ways to enhance human health.
Reference:
1. Tucker, et al., Free Radic Biol Med., 2015
2. Tucker, et al., Sports Med Open., 2016
3. Keller, et.al., New England Journal of Medicine, 2003