| Project/Area Number |
12671389
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Orthopaedic surgery
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TOHYAMA Harukazu Hokkaido Univ., Grad. School of Medicine, Prof., 大学院・医学研究科, 助教授 (60301884)
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| Co-Investigator(Kenkyū-buntansha) |
ITHO Hiroshi Hokkaido Univ., Grad. School of Medicine, Inst., 大学院・医学研究科, 助手 (80261296)
AOKI Yoshimitu Hokkaido Univ., Medical Hospital, Lect., 医学部・附属病院, 講師 (10192858)
YASUDA Kazunori Hokkaido Univ., Grad. School of Medicine, Prof., 大学院・医学研究科, 教授 (20166507)
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| Project Period (FY) |
2000 – 2001
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| Keywords | Tendon / Ligament / Tendon graft / Ligament reconstruction / Collagen / Remodeling / Fibroblasts / Extracellular matrix |
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| Research Abstract |
1. Methods:
(1) For 55 Wistar rats (14-week-old), the right patellar tendon underwent the in situ freeze-thaw treatment to necrotize intrisic fibrblasts of the tendon and the left knees underwent the sham-operation in order to test the hypothesis that extrinsic cells which infiltrate in the necrotized patellar tendon synthesize type-III.
(2) We examined the in situ frozen-thawed patellar tendon at 2 to 12 weeks after the treatment with immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) and mechanical evaluations. We also evaluated the effect of the in situ freeze-thaw treatment on viability of instrinsic fibroblasts using a tissue-culture technique.
2. Results:
(1) Tissue culture showed that no cell outgrowth was observed from all explants of the tendons after the freeze-thaw treatment, while fibroblast outgrowth was observed from 83.0 % of the explants in the non-treated tendon.
(2) Immunohistochemical findings showed that positive type-III collagen staining was observed around the extrinsic cells which infiltrate in the necrotized tendon at 3,6, and 12 weeks.
(3) In addition, RT-PCR analysis showed that the expression level of type-III procollagen mRNA in the frozen-thawed tendon was significantly higher than that in the sham-operated tendon at 6 and 12 weeks.
(4) Mechanical evaluations confirmed that the cross-sectional area of the in situ frozen-ghawed tendon at 6 weeks was significantly greater than that of the sham-operated tendon, while its elastic modulus was significantly lower that that of the sham-operated tendon.
3. Conclusion: This study suggested that extrinsic cells which infiltrated in the necrotized patellar tendon synthesize type-III collagen in the physiological mechanical environment. The present study indicated that the increase of type-III collagen in the tendon graft is unavoidable, even if we can avoid depriving the graft of stress.
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