Differences in myocardial and peripheral VEGF and KDR levels after acute ischemia

Recent clinical use of vascular endothelial growth factor (VEGF) in the treatment of both myocardial and peripheral ischemia has suggested the possibility of tissue specific coregulation of VEGF and its receptors (eg, kinase domain region [KDR]). The present study was performed to detect the relationship between VEGF and KDR protein levels after acute myocardial and peripheral ischemia.

Eleven dogs were divided into two groups: peripheral ischemia (n = 6, ligation of major limb arteries) and myocardial ischemia (n = 5, circumflex artery ligation). Muscle biopsy specimens were taken from the perfusion territories of the occluded circumflex artery and limb arteries 3 hours and 6 hours after ligation. Protein levels were determined using Western blot analysis.

In myocardium, VEGF levels increased on average eightfold from baseline (p < 0.05) both 3 hours and 6 hours after occlusion, whereas myocardial KDR levels dropped by about 60% at 3 hours and 80% at 6 hours (p < 0.05). With limb ischemia, both VEGF and KDR levels were significantly elevated at 3 hours.

In acute ischemia, regulation of VEGF and KDR may be controlled differently in cardiac and skeletal muscle. Myocardial KDR levels showed a significant decrease from baseline compared with a significant rise with peripheral ischemia.