Effects of short-term vibration and hypoxia during high-intensity cycling exercise on circulating levels of angiogenic regulators in humans.
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.
Suhr
Frank
F
Institute of Training Science and Sport Informatics, German Sport Univ. Cologne, Köln, Germany. Suhr@dshs-koeln.de
Brixius
Klara
K
de Marées
Markus
M
Bölck
Birgit
B
Kleinöder
Heinz
H
Achtzehn
Silvia
S
Bloch
Wilhelm
W
Mester
Joachim
J
D000328:Adult; D000531:Altitude; D043924:Angiogenesis Modulating Agents / Q000097:blood*; D001642:Bicycling / Q000502:physiology*; D043169:Endostatins / Q000097:blood / Q000378:metabolism; D005080:Exercise Test; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000097:blood / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000097:blood / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D010100:Oxygen; D005082:Physical Exertion / Q000502:physiology*; D011897:Random Allocation; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000097:blood / Q000378:metabolism; D014732:Vibration
D043924:Angiogenesis Modulating Agents; D043169:Endostatins; D042461:Vascular Endothelial Growth Factor A; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D010100:Oxygen