【Abstract】 Objective To investigate the angiogenesis in hypertropic scar tissue of rabbit ears at different periods and to explore a new method to prevent hyperplastic scar. Methods Nineteen Japanese white rabbits(weigthing 2.0-2.5 kg) were made animal models of hypertropic scar of ear. At 10th, 30th, 60th and 90 days, after epithel ization, the microvessel and microcirculation in hyperplastic scar of 8 rabbits were studied by microcirculation microscope and laser Doppler flowmetry. The other 11 rabbits’ right or left ears were randomly chosen into experimental group and control group. At 10 days after epithel ization,40 μL of adenovirus extracellular protein with metalloprotease and thrombospondin 1 domains (Ad-METH1) was injected into tissue of scar along the perimeter of the scar in experimental group. The same volume of empty adenovirus was injected in control group. After 30 days of injection, the gross appearance of 10 rabbits’ ears scar was recorded, the number of microvessel in scar
was counted and HE stainning of scar tissue was performed in experimental and control groups. One additional rabbit was used to evaluate the mRNA and protein expression of METH1 by RT-PCR and Western blot after 3 days of injection. R e sults The average number of microvessel at 10, 30, 60 and 90 days after epithel ization was 42.37 ± 3.89, 49.46 ± 4.13, 33.12± 4.34 and 13.24 ±2.31, respectively; the average value of microcirculatory perfusion at 10, 30, 60 and 90 days after epithetl ization was (37.75 ±2.11), (59.87 ± 6.46), (44.53 ± 6.14) and (29.21 ± 1.84)PU; the density of microvessels and perfusion of microcirculation in scar tissues during prol iferative stage (from 10 to 60 days after epithel ization) were markedly higher than that during mature period (90 days after epithel ization, P lt; 0.05).At 10 to 30 days after epithel ization, the histol igical features of scar showed early stage of prol iferation and prol iferative stage appearance; at 60 days after epithel ization, it is still in prol iferative stage, while some of scars were in mature phase; at 90 days after epithel ization, the histol igical features of scar were mature period appearance. At 3 days after Ad-METH1 injection, METH1 gene was successfully expressed at both mRNA and protein levels in experimental group, but not in control group. At 30 days after injection, the gross appearance
observation showed that scars in experimental group were flat and soft with the color close to normal, but scars in
control group were obvious and hard. The number of microvessel of scar tissue was 12.38±2.56 in experimental group and 48.12±6.46 in control group, showing statistically significant difference between two groups(P lt; 0.01). In experimental group, HE staining shows that the density of microvessel and the number of fibroblasts were greatly decreased and collagen fibers arranged regularly. In control group, plenty of fibroblasts and abundant microvessels were observed. Thick and tight collagen fibers were seen in the outer layer of dermis with a irregular arrangement. Conclusion Theanti-angiogenesis by Ad-METH1 may have a promising appl ication in the prevention of human hyperthropic scar.
Citation： SONG Baoqiang,LU Kaihua,ZHANG Yang,GUO Shuzhong,HAN Yan,MA Fucheng,LI Huiyuan. ANGIOGENESIS IN HYPERTROPHIC SCAR OF RABBIT EARS AND EFFECT OF EXTRACELLULAR PROTEINWITH METALLOPROTEASE AND THROMBOSPONDIN 1 DOMAINS ON HYPERTROPHIC SCAR. Chinese Journal of Reparative and Reconstructive Surgery, 2008, 22(1): 70-74. doi: Copy