جستجوی مقالات مرتبط با کلیدواژه "thrombospondin-1" در نشریات گروه "تربیت بدنی"

The development of new blood vessels involves the stimulation of growth, migration, and stabilization, which is influenced by various stimulating and inhibiting factors such as Thrombospondin-2 (TSP-2) and transforming growth factor-beta (TGF-β). This study aimed to compare the effect of eight weeks of different aerobic training methods on the expression of TSP-2 and TGF-β genes in subcutaneous adipose tissue of rats.

The study conducted an experimental research on 32 male Wistar rats to investigate the effects of different training protocols on gene expression. The rats were divided into four groups (n=8): scheme, high-intensity training (HIT), moderate-intensity training (MIT), and high-intensity interval training (HIIT). The training protocols involved treadmill running for eight weeks, with varying intensities and durations for each group. Gene expression was measured by RT-PCR method. The data were analyzed with one-way ANOVA and Tukey’s tests at a significance level of p≤0.05.

The results of the study show that all three training methods led to a significant reduction in TGF-β expression compared to the scheme group. However, no significant difference was observed between training methods. It was also found that only the HIT and MIT methods caused a significant decrease in TSP-2 expression compared to the scheme group, and that HIT could significantly reduce the expression of TSP-2 compared to the HIIT protocol.

 In conclusion, it is suggested that aerobic exercises, particularly HIT with specific intensity and duration, may be effective in improving blood supply to fat tissue and subsequently reducing fat mass through their impact on the expression of angiostatic genes.

Physiological angiogenesis and homeostasis of blood vessels is a complex process that is regulated at a high level by the balance between positive proteins such as follistatin-like factor-1 (FSTL-1) and negative proteins such as thrombospondin-1 (TSP-1). While there is considerable evidence about the role of positive factors in angiogenesis, however, the role of negative factors is not well defined. In physiological conditions, such as resistance training as one of the effective training methods to improve cardiovascular function, the role of these factors is not properly known. The aim of this study was to investigate the response of thrombospondin-1 and follistatin-like factor-1 of heart tissue to six weeks of resistance training in obese male rats.

In an experimental study, 20 Wistar male rats were divided into two equal groups of control and experimental based on weight homogenization. The experimental group participated in a six-week training protocol with a frequency of three training sessions per week, and each session included 10 repetitions with a 90-second rest interval, climbing a resistance training ladder at a height of one meter and an 85-degree incline with a weight attached to the base of the tail (according to the maximum weight carrying capacity of each rat). 48 hours after the last training session, TSP-1 and FSTL-1 values in heart tissue were evaluated using ELISA method. In order to examine the changes between groups, independent t-test were used at a significance level of p<0.05.

The findings showed that performing six weeks of resistance training protocol in the experimental group compared to the control group caused a significant increase in FSTL-1 values (p=0.0001) and a non-significant decrease in TSP-1 values (p=0.09).

It was determined based on the results of this study that intervention of exercise for six weeks of resistance exercises can have positive effects on the development of angiogenesis process in heart tissue. Based on the findings of this study, it seems that six weeks of resistance training, despite the significant decrease in TSP-1 as an inhibitory factor in the angiogenesis process and an increase in FSTL-1 values as an angiogenesis stimulating factor, may have positive effect on improving blood supply to the heart muscle in obese subjects. The data of the present study refer to the role of resistance training in facilitating intracellular signaling pathways that modulate some inhibitory factors and stimulatory factors in heart tissue angiogenesis in obese rats.

The expansion of fat tissue depends on its angiogenesis rate, and exercise activities affect various angiogenic factors in this tissue. With the expansion of fat tissue and adipogenesis, a dense and closed capillary network is formed in this tissue, which can suppress angiogenic factors. If there is a wide capillary network and angiogenic factors such as VEGF-A in this tissue, the expansion of fat tissue can be prevented. The aim of this study was to investigate and compare the effect of a variety of endurance exercises on the expression of angiogenic genes vascular endothelial growth factor (VEGF-A) and thrombospondin-1 (TSP-1) in the subcutaneous fat tissue of rats.

In this experimental study, 32 male Wistar rats aged eight weeks and weighing 237 ± 33 grams were randomly divided into four equal groups of control, high-intensity progressive continuous aerobic training (HIT), moderate-intensity continuous aerobic training (MIT) and, high-intensity interval aerobic training (HIIT). The treadmill training protocols consisted of eight weeks, so that the HIT training consisted of running at a speed of 20 m/min or at an intensity of 65% of the maximum oxygen consumption (VO2max), with a gradually increasing slope for 30 minutes. MIT training consisted of running with an intensity of 65% VO2max for 37 minutes, and HIIT training consisted of four high-intensity intervals with four minutes of running with an intensity of 90-100% VO2max and four low-intensity intervals with a duration of three minutes with 50-60% VO2max (28 minutes in total). Finally, 48 hours after the last training session, the subcutaneous fat tissue was isolated and the expression of VEGF-A and TSP-1 genes in the subcutaneous fat tissue was measured by RT-qPCR method. The resulting data were analyzed using a one-way analysis of variance and Tukey's post hoc test, and the significance level was considered P ≤ 0.05.

The findings of the present study showed that all three exercise interventions significantly increased the expression of the VEGF-A gene in subcutaneous fat tissue; But only HIT training could significantly reduce the expression of TSP-1 in this tissue (P ˂ 0.05). Also, the increase in VEGF-A expression was significantly higher after HIT training compared to HIIT (P ˂ 0.05).

According to the findings of this study, high-intensity and progressive continuous aerobic training is probably the most desirable training method to increase angiogenesis in subcutaneous fat tissue. These types of exercises can be effective in reducing fat mass by improving blood supply to fat tissue.