|
|
||||||||
1 Department of Physiology and Pharmacology, Loma Linda University, Loma Linda 92350; and 2 Division of Physiology, Department of Medicine, University of California, San Diego, La Jolla, California 92093-0623
Vascular endothelial
growth factor (VEGF) is a hypoxia-inducible angiogenic mitogen.
However, chronic hypoxia is generally not found to increase mammalian
skeletal muscle capillarity. We sought to determine the effect of
chronic hypoxia (8 wk, inspired O2 fraction = 0.12) on
skeletal muscle gene expression of VEGF, its receptors (flt-1 and
flk-1), basic fibroblast growth factor, and transforming growth
factor-
1. Wistar rats were exposed to chronic hypoxia
(n = 12) or room air (n = 12). After
the exposure period, six animals from each group were subjected to a
single 1-h treadmill exercise bout (18 m/min on a 10° incline) in
room air while the remaining six animals served as rest controls.
Morphological analysis revealed that chronic hypoxia did not increase
skeletal muscle capillarity. Northern blot analyses showed that chronic hypoxia decreased resting VEGF, flt-1, and flk-1 mRNA by 23, 68, and
42%, respectively (P < 0.05). The VEGF mRNA response
to exercise was also decreased (4.1- and 2.7-fold increase in room air
and chronic hypoxia, respectively, P < 0.05). In
contrast, neither transforming growth factor-
1 nor basic
fibroblast growth factor mRNA was significantly altered by chronic
hypoxia. In conclusion, prolonged exposure to hypoxia attenuated gene
expression of VEGF and its receptors flt-1 and flk-1 in rat
gastrocnemius muscle. These findings may provide an explanation for the
lack of mammalian skeletal muscle angiogenesis that is observed after
chronic hypoxia.
Northern blot analysis; angiogenesis; transforming growth
factor-
1; basic fibroblast growth factor
This article has been cited by other articles:
![]() |
N. A. Ryan, K. A. Zwetsloot, L. M. Westerkamp, R. C. Hickner, W. E. Pofahl, and T. P. Gavin Lower skeletal muscle capillarization and VEGF expression in aged vs. young men J Appl Physiol, January 1, 2006; 100(1): 178 - 185. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. M. Yau, G. Li, Y. Zhang, R. D. Weisel, D. A.G. Mickle, and R.-K. Li Vascular Endothelial Growth Factor Receptor Upregulation in Response to Cell-Based Angiogenic Gene Therapy Ann. Thorac. Surg., June 1, 2005; 79(6): 2056 - 2063. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. E. Waters, S. Rotevatn, P. Li, B. H. Annex, and Z. Yan Voluntary running induces fiber type-specific angiogenesis in mouse skeletal muscle Am J Physiol Cell Physiol, November 1, 2004; 287(5): C1342 - C1348. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Lundby, H. Pilegaard, J. L. Andersen, G. van Hall, M. Sander, and J. A. L. Calbet Acclimatization to 4100 m does not change capillary density or mRNA expression of potential angiogenesis regulatory factors in human skeletal muscle J. Exp. Biol., October 15, 2004; 207(22): 3865 - 3871. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. M. Prior, H. T. Yang, and R. L. Terjung What makes vessels grow with exercise training? J Appl Physiol, September 1, 2004; 97(3): 1119 - 1128. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. P. Gavin and P. D. Wagner Acute ethanol increases angiogenic growth factor gene expression in rat skeletal muscle J Appl Physiol, March 1, 2002; 92(3): 1176 - 1182. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. M. Olfert, E. C. Breen, O. Mathieu-Costello, and P. D. Wagner Skeletal muscle capillarity and angiogenic mRNA levels after exercise training in normoxia and chronic hypoxia J Appl Physiol, September 1, 2001; 91(3): 1176 - 1184. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. B. McClelland and G. A. Brooks Changes in MCT 1, MCT 4, and LDH expression are tissue specific in rats after long-term hypobaric hypoxia J Appl Physiol, April 1, 2002; 92(4): 1573 - 1584. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |