Angiogenic effect of intercellular adhesion molecule-1.

UNLABELLED: In order to investigate the angiogenic effect of intercellular adhesion molecule-1 (ICAM-1), two parts of experiment were performed. Chick embryo chorioallantoic membrane (CAM) assay was used for in vivo angiogenic research. The chick embryos were divided into 4 groups: ICAM-1 group (divided into 3 subgroups, I, II and III) for screening the angiogenic effect of ICAM-1 by adding different concentrations of ICAM-1 (0.1, 0.2 and 0.3 microg/microL) 5 microL into the chick embryo CAMs on the day 10 after incubation for every subgroup; Anti-ICAM-1 group A (divided into 2 subgroups, I and II) by adding different concentrations of Anti-ICAM-1 (1:100, 1:50) 5 microL into the chick embryo CAMs on the day 10 after incubation for every subgroup to evaluate the effect of ICAM-1 on the survival of microvessels through observing whether Anti-ICAM-1 could induce involution of the microvessels on CAMs; Anti-ICAM-1 group B (divided into 2 subgroups, I and II) by adding different concentrations of Anti-ICAM-1 (1:100, 1:50) 5 microL into the chick embryo CAMs on the day 6 after incubation for every subgroup to evaluate whether ICAM-1 involved in embryonic angiogenesis through observing the growth of microvessels on CAMs; CONTROL GROUP: ICAM-1 or Anti-ICAM-1 was substituted by PBS 5 muL on the day 10 or day 6 after incubation. Three days later, the CAMs were photographed in vivo, excised, sectioned and the number of microvessels was counted. In ICAM-1 group, there was increased number of microvessels arranged radially with "spoked-wheel" pattern around the gelatin sponges. The new microvessels growing perpendicularly to gelatin sponges were observed. The number of the microvessels growing in the CAM mesenchymes around the sponges in 3 subgroups was higher than that in control group (P<0.01), however, there was no significant difference among the 3 subgroups (P>0.05). In anti-ICAM-1 group A, the radially arranged microvessels were very unclear around the sponges contrast to that of ICAM-1 group. Few new microvessels were detected in the center of the sponges. The number of the microvessels growing in the CAM mesenchymes around the sponges in subgroup II was lower than that in control group (P<0.01). There was no significant difference in the number of the microvessels around the sponges between subgroup I and control group (P>0.05). In anti-ICAM-1 group B, the radially arranged microvessels were very unclear around the sponges contrast to that of control group. New microvessels were very scarce in the center of the sponges. The number of the microvessels growing in the CAM mesenchymes around the sponges in the 2 subgroups were less than that in control group (P<0.01), and there was significant difference between the 2 subgroups (P<0.05). It was suggested that ICAM-1 could induce angiogenesis and support the survival of microvessels, and ICAM-1 was involved in embryonic angiogenesis.