Ethics code: IR.PNU.REC.1398.059
Payame Noor University, Tehran, Iran , ali_barzegari@pnu.ac.ir
Abstract: (1862 Views)
Background and Aims: Trainings resulting from training include increased protein synthesis, mitochondrial biogenesis, neurogenesis, angiogenesis, and apoptosis. One of the most important factors affecting training with different intensities is insulin-like growth factor (IGF1-1). IGF1-1 is a 70 amino acid peptide hormone secreted by the liver. This hormone plays a major role in controlling cellular aging and longevity. There are six proteins capable of binding to IGF-1 (from IGFBP-1 to IGFBP-6) that vary in their binding to IGF-1. Studies on the effect of intermittent training on hormonal adjustment are limited. However, the study of changes in anabolic hormones, including IGFBP-1, is effective in monitoring the effect of such trainings on cellular signaling, including protein synthesis, neurogenesis, and angiogenesis. It also shows that the effect of these hormones has not been studied with the desired high-intensity training approach. Therefore, the question of the present study is whether there is a difference between the effect of three training methods with different intensities on the expression of IGFBP-1 gene in the liver tissue of male Wistar rats?
Methods: The present study was approved by the ethics committee of Payame Noor University with the code IR.PNU.REC.1398.059. In terms of purpose, it is fundamental-applied, which was implemented experimentally. In the present study, 32 8-week-old male Wistar rats with an average weight of 237 ±33 g were purchased from the Pasteur Institute. After being transferred to the animal laboratory environment, these animals are housed in transparent polycarbonate cages in an environment with a temperature of 22 ± 1.4 °C, the humidity of 45 to 55%, four heads in each cage with free access to water and closed. Foods were maintained according to a 12-hour sleep-wake cycle. Animals were randomly divided into 5 groups: control group (Co) (8 heads), moderate intensity training (MIT) (8 heads), high-intensity training (HIT) (8 heads), and high-intensity interval training (HIIT) (8 heads) were divided. The MIT protocol was performed in such a way that in the first week, 5 minutes of warm-up, 5 minutes of cooling, and 20 minutes of the main body of the exercise, including running at 65% VO2max at a speed of 20 m/min, was added to the training time every week. In the sixth week, the training time reached 37 minutes and remained constant until the end of the eighth. Also, the training speed was unchanged from the first week to the eighth week and was equal to 20 meters per minute.
The HIT protocol in the first week included: 5 minutes of warm-up, 5 minutes of cooling, and 20 minutes of running training with 65% VO2max at a speed of 20 m/min and an increasing slope of the treadmill. The training time was increased every week, so that in the sixth week the training time reached 30 minutes and remained constant until the end of the eighth. On the other hand, the slope of the strip was 2% in the first and second weeks and 2% was added to the slope every 2 weeks to reach 8% in the seventh and eighth weeks. Also, the training speed from the first week to the eighth week was 20 meters per minute and was kept constant.
The HIIT protocol also included 10 minutes of warm-up before the workout, in the first to fourth weeks including 3 intense intermittent runs with an intensity of 90 to 100% VO2max and a speed of 30 meters per minute in 4 minutes and 3 low-intensity intermittent runs. With 50 to 60% VO2max and at a speed of 20 meters per minute in 3 minutes. From the fifth to the eighth week, it also includes 4 intense intermittent runs with an intensity of 90 to 100% VO2max at a speed of 30 meters per minute in 4 minutes and 3 low-intensity intermittent runs with 50 to 60% VO2max at a speed of 20 meters per minute. It took 3 minutes. The main body time of the exercise was 28 minutes per repetition. Mice in the control group did not participate in any exercise program but were placed on a stationary treadmill for 10 to 15 minutes per session to adapt to the environment to create the same conditions.
After in vitro analysis of the samples, descriptive statistics including standard mean and standard deviation and inferential statistics were used to quantitatively describe the data. First, the Shapirovilk test was used to determine the normality of data distribution, and the Leven test was used to determine the homogeneity of variance. Due to the normal distribution of data, parametric tests including one-way analysis of variance and Tukey's post hoc test were used at a significance level of p≥0.05.
Results: The results of one-way analysis of variance showed that IGFBP1 gene expression in the liver tissue of rats in the study groups was statistically significant (P <0.001). Tukey post hoc test results also showed that there was a significant increase in IGFBP1 gene expression as a result of training compared to the control group (P = 0.001), as in the MIT and HIT groups compared to the HIIT group, There was a significant decrease in IGFBP1 expression (P = 0.001). However, the results showed that there was no significant difference between HIT and MIT groups (P = 0.412). Comparing the three training models, it was found that the expression of IGFBP1 in the HIIT group had a significant increase compared to other training groups (p = 0.001).
Conclusion: All three training methods were able to improve the expression of the studied genes and make favorable changes in reducing the consequences of liver tissue damage. However, it seems that HIIT trainings have had more favorable effects, although more research is needed in this area and the difference between the effect of current training protocols and the path of their possible signaling mechanisms is not clear and the need for research. There are more in this field. One of the limitations of the present study is the lack of control over calorie intake in rats and lack of control over physical activity outside the animal research program. However, the research background on the effect of the present study training protocols on IGFBP-1 in liver tissue is very limited and needs further investigation.
Type of Study:
Research |
Subject:
Exercise Physiology