2005 Fiscal Year Final Research Report Summary
Remodeling of vein graft in noromocholesterolemic or hypercholesterolemic rabbits
| Project/Area Number |
16390391
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thoracic surgery
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
TANAKA Hiroyuki Tokyo Medical and Dental University, Graduate School, Thoracic Cardiovascular Surgery, Associate Professor, 大学院医歯学総合研究科, 助教授 (70197466)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Jun-ichi Tokyo Medical and Dental University, Hospital Faculty of Medicine, Assistant, 医学部附属病院, 助手 (90313858)
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| Project Period (FY) |
2004 – 2005
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| Keywords | vein graft / hypercholesterolemia / rabbit |
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| Research Abstract |
We studied the remodeling of vein graft implanted into the carotid artery in normo-or hypercholesterolemic rabbit. Vein grafts were harvested 8weeks after surgery and evaluated by pathological characteristics. Hypercholesterolemia (800mg/dl) significantly decrease the patency rate (35%) compared to that in normocholesterolemic (50mg/dl) rabbits (83%) at 8 weeks post surgery. In patent vein grafts of hypercholesterolemic rabbits, focal foamy cell rich lesions and luminal fibrin-like thrombus were observed along with fibroproliferative lesions. In vein grafts in normocholesterolemic rabbits, intimal thickening consited of only SMC proliferation and no macrophages, were observed and lumen was widely open, suggesting that SMC proliferation was adaptive response of vein graft implanted in high pressure circulation and not cause of graft occlusion. In some occluded vein grafts, luminal thrombus formation that seemed to be derived from foamy cell rich lesions, was observed. These pathological findings suggested that rupture of unstable plaque and subsequent thrombus formation play a crucial role in mechanism of vein graft occlusion. We also evaluated the effects of ACAT inhibition on vein graft remodeling. ACAT inhibition did not improve the patency rate of vein graft in hypercholesterolemic rabbits, It may tend to stabilize the lesion characteristics, but there was no significant difference in lesion size, area of foamy cell rich lesions between treated group and control group.
As clinical implications, aggressive cholesterol lowering therapy and anticoagulation therapy may be important in post operative medical therapy after bypass surgery and therapeutic target must be focused on the stabilization of the plaque on vein grafts.
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Research Products
(2 results)
