Effects of short-term vibration and hypoxia during high-intensity cycling exercise on circulating levels of angiogenic regulators in humans

Abstract

This study aimed to investigate the biological response to hypoxia as a stimulus, as well as exercise- and vibration-induced shear stress, which is known to induce angiogenesis. Twelve male cyclists (27.8 +/- 5.4 yr) participated in this study. Each subject completed four cycle training sessions under normal conditions (NC) without vibration, NC with vibration, normobaric hypoxic conditions (HC) without vibration, and HC with vibration. Each session lasted 90 min, and sessions were held at weekly intervals in a randomized order. Five blood samples (pretraining and 0 h post-, 0.5 h post-, 1 h post-, and 4 h posttraining) were taken from each subject at each training session. Hypoxia was induced by a normobaric hypoxic chamber with an altitude of 2,500 m. The mechanical forces (cycling with or without vibration) were induced by a cycling ergometer. The parameters VEGF, endostatin, and matrix metalloproteinases (MMPs) were analyzed using the ELISA method. VEGF showed a significant increase immediately after the exercise only with exogenously induced vibrations, as calculated with separate ANOVA analysis. Endostatin increased after training under all conditions. Western blot analysis was performed for the determination of endostatin corresponding to the 22-kDa cleavage product of collagen XVIII. This demonstrated elevated protein content for endostatin at 0 h postexercise. MMP-2 increased in three of the four training conditions. The exception was NC with vibration. MMP-9 reached its maximum level at 4 h postexercise. In conclusion, the results support the contention that mechanical stimuli differentially influence factors involved in the induction of angiogenesis. These findings may contribute to a broader understanding of angiogenesis.

The Long-Term Effects of Colostrum Supplementation and Sprint-Endurance Training on Plasma VEGF Levels in Male Wistar Rats

“…Results of the present study revealed increased VEGF levels for sprint-endurance training groups without supplementation, which are consistent with the results of some studies 23,25,28 while different from the results of some other studies. 8,29 The specific training method applied in this study could account for such contradictory results. In addition to the aforesaid training method, different timings of the blood sample collection may also account for the contradictory results of the present study and the study conducted by Thorell et al 17 In fact, in the latter study blood sampling was performed 1 hour after exercise, whereas in the present study blood samples were collected 24 hours after the last training session and in the morning on an empty stomach.…”

“…25 As shown in some previous studies, serum VEGF values increased after exercise, 26,28 whereas other studies reported no changes in serum VEGF levels after acute exercise. 8,27 In addition, Gu et al reported reduced serum VEGF concentration after exercise. 29 Several studies have also contemplated the effect of free radicals on angiogenesis.…”

“…the involvement of various cells, signaling pathways, growth factors and receptors, 6 and eventually induces the growth of new blood vessels from pre-existing vessels via the 2 sprouting 7,8 and longitudinal splitting 1 modes. Vascular endothelial growth factor (VEGF) is the main mitogen involved in angiogenesis.…”

“…Vascular endothelial growth factor (VEGF) is the main mitogen involved in angiogenesis. VEGF is a 45 kDa glycoprotein mostly secreted from endothelial cells 8 and tumor cells. 3,9,10 It leads to the survival, proliferation, and migration of endothelial cells, and ultimately, formation of new blood vessels by binding to its receptor, which is, VEGF receptor-2 (VEGFR-2).…”

The Effect of 8 Weeks Aerobic Training on Angiogenesis (VEGF) and Angiostatic (ES) Factors In Sedentary Women

“…The extension of this network is done through arteriogenesis and angiogenesis processes on the The Effect of 8 Weeks Aerobic Training on Angiogenesis (VEGF) and Javad Tolouei Azar, et al 8 vascular bed of skeletal muscle which decrease or omit the stress caused by sport act in ties (5).…”