21. MYOCARDIAL AND PERIPHERAL VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) AND RECEPTOR (KDR) LEVELS IN RELATION TO TIME AND LOCATION AFTER ACUTE ISCHEMIA
Reza Miraliakbari, Nicola A. Francalancia, Robert M. Lust, Dirk J. Vice, Peter C. Ng, Mel S. Swanson, You S. Sun, W. Randolph Chitwood, Jr.*
East Carolina University School of Medicine, Department of Surgery
Greenville, North Carolina, USA
BACKGROUND
Recent clinical use of VEGF in treatment of myocardial ischemia has suggested the possibility of co-regulation of VEGF and its receptors. The present study was performed to detect any relationship between myocardial and peripheral VEGF and KDR protein levels in acute ischemia.
MATERIAL AND METHODS
Eleven dogs were divided into two groups: (1) peripheral (n=6, ligation of major limb artery) and (2) myocardial (n=5, circumflex artery (CxA) ligation). Muscle biopsies were taken at several locations from occlusion in CxA and limb artery territories; 3 hr and 6 hr after ligation. Protein levels were determined using Western Blot analysis.
RESULTS
In myocardium, VEGF levels increased an average of eight-fold (P<0.05) at both 3 hr and 6 hr after occlusion; however, myocardial KDR levels dropped by 60% at 3 hr and by 80% at 6 hr (P<0.05). In limb ischemia, VEGF and KDR levels were both elevated. Results are expressed in the Table as % change from baseline protein levels.
|
|
3 hr-At Ligation |
3 hr- Midvessel |
3 hr-Distal |
6hr-At Ligation |
6 hr- Midvessel |
6 hr-Distal |
|
CxA-KDR |
-59.75 |
-63.28 |
-54.69 |
-79.89 |
-80.01 |
-72.93 |
|
Limb-KDR |
173.32 |
144.81 |
858.83 |
110.67 |
274.56 |
32.36 |
|
CxA-VEGF |
879.28 |
763.35 |
1137.08 |
1095.78 |
577.35 |
837.94 |
|
Limb-VEGF |
39.56 |
111.66 |
326.94 |
128.19 |
473.12 |
147.70 |
CONCLUSION
In acute ischemia, regulation of VEGF and KDR may be controlled differently in myocardium and extremities. Further research is needed to delineate this difference since it will have bearing on proper administration of exogenous VEGF.
