Synergistic effect of vascular endothelial growth factor and basic fibroblast growth factor on angiogenesis in vivo.
BACKGROUND
Recent studies have suggested that vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) may have synergistic effects on the induction of angiogenesis in vitro. Therefore, we investigated the hypothesis that the simultaneous administration of VEGF and bFGF, each having been previously shown to independently enhance collateral development in an animal model of hind limb ischemia, could have a synergistic effect in vivo.


RESULTS
Ten days after surgical induction of unilateral hind limb ischemia, New Zealand White rabbits were randomized to receive either VEGF 500 micrograms alone (n = 6), bFGF 10 micrograms alone (n = 7), VEGF 500 micrograms, immediately followed by 10 micrograms bFGF (n = 7), or vehicle only (control animals, n = 8) in each case administered intra-arterially via a catheter in the internal iliac artery of the ischemic limb. BP ratio (BPR, ischemic/healthy limb) at day 10 for the VEGF+bFGF group was 0.82 +/- 0.01, much superior (P < .0005) to that of either the VEGF group (0.52 +/- 0.02) or the bFGF group (0.57 +/- 0.02). This outcome persisted at day 30: BPR in the VEGF+bFGF group (0.91 +/- 0.02) exceeded that of the control group (0.49 +/- 0.05, P < .0001), the VEGF group (0.65 +/- 0.03, P < .0005), or the bFGF group (0.66 +/- 0.03, P < .0005). Serial angiography demonstrated a progressive increase in luminal diameter of the stem collateral artery and the number of opacified collaterals in the thigh of the ischemic limbs in all groups. Stem artery diameter with VEGF+bFGF (1.34 +/- 0.07 mm) on day 30 was significantly (P < .05) greater than with either VEGF (1.09 +/- 0.09) or bFGF (1.18 +/- 0.06) alone. Capillary density was significantly greater (P < .05) in VEGF+bFGF animals (275 +/- 20 mm2) compared with VEGF (201 +/- 8) or bFGF (209 +/- 15).


CONCLUSIONS
Combined administration of VEGF and bFGF stimulates significantly greater and more rapid augmentation of collateral circulation, resulting in superior hemodynamic improvement compared with either VEGF or bFGF alone. This synergism of two angiogenic mitogens with different target cell specificities may have important implications for the treatment of severe arterial insufficiency in patients whose disease is not amenable to direct revascularization.
Asahara
T
T
Department of Medicine (Cardiology), St Elizabeth's Medical Center, Tufts University School of Medicine, Boston, Mass 02135, USA.
Bauters
C
C
Zheng
L P
LP
Takeshita
S
S
Bunting
S
S
Ferrara
N
N
Symes
J F
JF
Isner
J M
JM
D000792:Angiography; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002196:Capillaries / Q000187:drug effects / Q000473:pathology; D004357:Drug Synergism; D016228:Endothelial Growth Factors / Q000494:pharmacology*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006614:Hindlimb / Q000098:blood supply*; D007511:Ischemia / Q000000981:diagnostic imaging / Q000188:drug therapy*; D008222:Lymphokines / Q000494:pharmacology*; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D011817:Rabbits; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2