Effect of short-term exercise training on angiogenic growth factor gene responses in rats.
We investigated whether 1) 5 days of exercise training would reduce the acute exercise-induced increase in skeletal muscle growth factor gene expression; and 2) reductions in the increase in growth factor gene expression in response to short-term exercise training would be coincident with increases in skeletal muscle oxidative potential. Female Wistar rats were used. Six groups (rest; exercise for 1-5 consecutive days) were used to measure the growth factor response through the early phases of an exercise training program. Vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1), and basic fibroblast growth factor (bFGF) mRNA were analyzed from the left gastrocnemius by quantitative Northern blot. Citrate synthase activity was analyzed from the right gastrocnemius. VEGF and TGF-beta1 mRNA increased after each of 5 days of exercise training, whereas exercise on any day did not increase bFGF mRNA. On day 1, the VEGF mRNA response was significantly greater than on days 2-5. However, the reduced increase in VEGF mRNA observed on days 2-5 was not coincident with increases in citrate synthase activity. These findings suggest that, in skeletal muscle, 1) VEGF and TGF-beta1 mRNA are increased through 5 days of exercise training and 2) the reduced exercise-induced increase in VEGF mRNA responses on days 2-5 does not result from increases in oxidative potential.
Gavin
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TP
Department of Medicine, University of California San Diego, La Jolla, California 92093-0623, USA. gavint@mail.ecu.edu
Wagner
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PD
D000818:Animals; D002950:Citrate (si)-Synthase / Q000096:biosynthesis; D016228:Endothelial Growth Factors / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000235:genetics*; D005786:Gene Expression Regulation; D008222:Lymphokines / Q000096:biosynthesis / Q000235:genetics*; D010084:Oxidation-Reduction; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D005346:Fibroblast Growth Factors; D002950:Citrate (si)-Synthase