[Osteonecrosis of the femoral head in spontaneously hypertensive rats--electron microscopic study of the growth plate in the femoral head].
The growth plate of the femoral heads in growing spontaneously hypertensive rats (SHRs) was investigated histologically and ultrastructurally, to clarify the causes of femoral head lesions: osteonecrosis and/or ossification disturbance of the epiphysis. As compared with the normal femoral heads, histological abnormalities of the growth plate in the weight-bearing area of the femoral heads, such as decreased thickness and nodular formation etc., frequently accompanied femoral head lesions. Ultrastructural observation disclosed that the most of chondrocytes in the growth plate with decreased thickness were in the degenerative condition. Chondrocytes in nodular formation showed the fine structure reflecting the accelerated cell metabolism or mild degeneration indicating the regenerative process. It suggested that the disorder of chondrocytes would weaken the architecture of the cartilaginous canal where the blood vessels pass to the proximal femoral epiphysis, and that the obstruction of the cartilaginous canal would cause the femoral head lesions in SHRs.
Kumashiro
T
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Department of Orthopaedic Surgery, Nagasaki University School of Medicine, Japan.
D000818:Animals; D005271:Femur Head Necrosis / Q000473:pathology*; D006132:Growth Plate / Q000502:physiology / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D010012:Osteogenesis / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains