| 1. |
|
|
| 2. |
- Gustafsson, T, et al.
(författare)
-
The influence of physical training on the angiopoietin and VEGF-A systems in human skeletal muscle
- 2007
-
Ingår i: Journal of applied physiology (Bethesda, Md. : 1985). - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 103:3, s. 1012-1020
-
Tidskriftsartikel (refereegranskat)abstract
- Eleven subjects performed one-legged exercise four times per week for 5 wk. The subjects exercised one leg for 45 min with restricted blood flow (R leg), followed by exercise with the other leg at the same absolute workload with unrestricted blood flow (UR leg). mRNA and protein expression were measured in biopsies from the vastus lateralis muscle obtained at rest before the training period, after 10 days, and after 5 wk of training, as well as 120 min after the first and last exercise bouts. Basal Ang-2 and Tie-1 mRNA levels increased in both legs with training. The Ang-2-to-Ang-1 ratio increased to a greater extent in the R leg. The changes in Ang-2 mRNA were followed by similar changes at the protein level. In the R leg, VEGF-A mRNA expression responded transiently after acute exercise both before and after the 5-wk training program. Over the course of the exercise program, there was a concurrent increase in basal VEGF-A protein and VEGFR-2 mRNA in the R leg. Ki-67 mRNA showed a greater increase in the R leg and the protein was localized to the endothelial cells. In summary, the increased translation of VEGF-A is suggested to be caused by the short mRNA burst induced by each exercise bout. The concurrent increase in the Ang-2-to-Ang-1 ratio and the VEGF-expression combined with the higher level of Ki-67 mRNA in the R leg indicate that changes in these systems are of importance also in nonpathological angiogenic condition such as voluntary exercise in humans. It further establish that hypoxia/ischemia-related metabolic perturbation is likely to be involved as stimuli in this process in human skeletal muscle.
|
|
| 3. |
|
|
| 4. |
- Rullman, E., et al.
(författare)
-
A single bout of exercise activates matrix metalloproteinase in human skeletal muscle
- 2007
-
Ingår i: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 102:6, s. 2346-2351
-
Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were 1) to characterize changes in matrix metalloproteinase (NIMP), endostatin, and vascular endothelial growth factor (VEGF)-A expression in skeletal muscle in response to a single bout of exercise in humans; and 2) to determine if any exchange of endostatin and VEGF-A between circulation and the exercising leg is associated with a change in the tissue expression or plasma concentration of these factors. Ten healthy males performed 65 min of cycle exercise, and muscle biopsies were obtained from the vastus lateralis muscle at rest and immediately and 120 min after exercise. In the muscle biopsies, measurements of mRNA expression levels of MMP-2, MMP-9, MMP-14, and tissue inhibitor of metalloproteinase; VEGF and endostatin protein levels; and NIMP activities were performed. Femoral arterial and venous concentrations of VEGF-A and endostatin were determined before, during, and 120 min after exercise. A single bout of exercise increased MMP-9 mRNA and activated MMP-9 protein in skeletal muscle. No measurable increase of endostatin was observed in the skeletal muscle or in plasma following exercise. A concurrent increase in skeletal muscle VEGF-A mRNA and protein levels was induced by exercise, with no signs of peripheral uptake from the circulation. However, a decrease in plasma VEGF-A concentration occurred following exercise. Thus 1) a single bout of exercise activated the MMP system without any resulting change in tissue endostatin protein levels, and 2) the increased VEGF-A protein levels are due to changes in the skeletal muscle tissue itself. Other mechanisms are responsible for the observed exercise-induced decrease in VEGF-A in plasma.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
