Evaluation of Angiogenic Inhibitors with an in vivo Quantitative Angiogenesis Method Using Agarose Microencapsulation and Mouse Hemoglobin Enzyme‐linked Immunosorbent Assay

In the present work, using a previously reported in vivo quantitative tumor‐angiogenesis model, we attempted to ascertain whether this animal model is suitable for practical use in monitoring inhibitors of tumor angiogenesis. Mouse sarcoma‐180 cells, human A431 cells or rat C6 cells microencapsulated in agarose beads were implanted s.c. into C57BL/6 mice. The level of blood vessel induction at the agarose pellet site was evaluated using mouse hemoglobin enzyme‐linked immunosorbent assay on day 10 after implantation. Hydrocortisone, tetrahydro‐S, medroxyprogesterone acetate, pentosan polysulfate and suramin inhibited blood vessel growth in our in vivo tumor‐angiogenesis assay system, and heparin enhanced the antiangiogenic effects of hydrocortisone and tetrahydro‐S. These results are almost entirely consistent with those observed in common assay systems, and suggest that this method may be useful for the identification and quantitative evaluation of inhibitors of tumor angiogenesis.