LIPOPROTEIN (A) INDUCES ANGIOGENESIS ON THE CHICK-EMBRYO CHORIOALLANTOIC MEMBRANE

Background Both lipoprotein (a) [Lp(a)] and angiogenesis have been sho wn to be associated with initiation and progression of atherosclerotic plaque. Lp(a) and two neutralizing anti-lp(a) antibodies were investi gated for their capacity to affect the vasoproliferative processes of the chick embryo chorioallantoic membrane (CAM), a useful model for su ch an investigation. Methods Gelatin sponges loaded with Lp(a) alone o r together with anti-lp(a) antibodies, or with vehicle alone, phosphat e-buffered saline (PBS), were implanted in vma onto the CAM at incubat ion day 8. Four days later, sponges and the adjacent CAM tissues were assessed for the extent of angiogenesis in terms of microvessel counts . Results Lp(a)-loaded sponges gave significantly higher counts than t hose loaded with the Lp(a)-anti-Lp(a) antibodies complex, which overla pped those treated with PBS. The angiogenic response was similar to th at obtained with basic fibroblast growth factor, a well-known angiogen ic molecule. Conclusion These data suggest that Lp(a) is capable of in ducing angiogenesis in vivo, which might account for its ability to en hance and support atherosclerosis.