|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1995 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1994 : ¥1,600,000 (Direct Cost : ¥1,600,000)
In order to elucidate the cause of osteonecrosis of the femoral head in spontaneously hypertensive rats (SHRs), which resembles the osteonecrosis of Perthes'disease, we investigated the development of the blood vessels forming the epiphyseal nucleus of the rat femoral heads, and the abnormalities of the blood vessels feeding the femoral heads of SHRs. The vascular casts of the proximal femur were observed using both an optical and a scanning electron microscopy (SEM). In the growing rats at the age of 5 weeks, the lateral epiphyseal vessela (LEVs) budded out from the arch of the blood vessels on the femoral neck. During the period of 9-15 weeks after birth, when osteonecrosis of the femoral heads in SHRs occurred frequently, LEVs, which were the main feeding vessels, entered from the lateral of the femoral heads. Anastomosing branches of LEVs between the epiphysis and the femoral neck were scarce even in the femoral heads showing normal ossification. It seemed that the development of LEVs did not proceed normally in this period. Furthermore, remarkable segmental stenosis and the obstruction of LEVs were often recognized near the lateral of the femoral heads.
These results suggested that LEVs in growing SHRs have the vascular structure that could cause an interruption of the blood supply to the femoral heads.
平成7年度では,SHRの成長にともなう骨頭栄養血管の変化および大腿骨頭壊死発生時の栄養血管所見も観察した。その結果,(1)大腿骨頭壊死を起こしていないものでも,LEVsが骨頭内へ貫通する部位で限局性に狭窄していること,(2)新鮮な壊死骨頭におけるLEVsの閉塞部位は,骨頭軟骨貫通部であることが明らかになった。このことはCalcified Tissue InternationalにCharacteristics of Blood Vessels Feeding the Femoral Head Liable to Osteonecrosis In Spontaneously Hypertensive Ratsの題名で掲載予定である。また,これら血管異常は,骨頭軟骨の脆弱性にもとずくことを示す組織所見が得られ、Vascular Occlusion and Cartilage Disorders in Osteonecrosis of the Femoral Head in Ratsの題名でInternational Orthopaedicsに掲載予定となっている。