The Role of Peroxisomes in Bone Formation

1. 5月龄胎牛关节软骨中过氧化物酶体的形态、分布及生物学功能。对胎牛软骨细胞匀浆进行蔗糖密度梯度离心。(1)胎牛软骨中含有正常大小的过氧化物酶体，密度约为1.25，但有报道称肝脏和肾脏外组织中含有低密度的微过氧化物酶体。(2)丙氨酸：glyoxylate aminotransferase(AGT)，是动物过氧化物酶体中唯一的转氨酶，广泛分布于哺乳动物肝脏。胎牛软骨过氧化物酶体未检测到AGT活性，提示胎牛软骨过氧化物酶体的功能与肝脏不同。(3) d -天冬氨酸氧化酶（D-Asp O）定位于胎牛软骨的过氧化物酶体中，提示该组织中存在d -天冬氨酸氧化酶，D-Asp O与发育过程有关。MC3T3-E1细胞（来源于小鼠的成骨样细胞）中过氧化物酶体的形态、分布及生物学功能。MC3T3-E1细胞匀浆检测过氧化氢酶活性，表明MC3T3-E1细胞中存在过氧化物酶体。匀浆中未检测到其他过氧化物酶体标记酶的活性。因此，必须进一步研究氯贝特（过氧化物酶体增殖剂）处理过氧化物酶体的增殖和一些过氧化物酶体的活性。

1. The morphology, distribution and biological function of peroxisomes in the fetal bovine articular cartilage of 5-month-old.Sucrose density gradient centrifugation of the homogenate from chondrocytes of the fetal bovine cartilage was performed.(1) The fetal bovine cartilage contained normal size peroxizomes with density of about 1.25, although it had been reported that the tissues out of liver and kidney contained microperoxisomes with low density.(2) Alanine : glyoxylate aminotransferase(AGT) which is only animotransferase in animal peroxisomes and is wide distributed in mammalian liver. AGT activity was not detected in peroxisomes of the fetal bovine cartilage, suggested that the function of peroxisomes in cartilage was different from liver.(3) D-aspartate oxidase(D-Asp O) was localized in peroxisomes in the fetal bovine cartilage, suggested that D-saparate was present in this tissue and D-Asp O was related to the developmental processes.2. The morphology, distribution and biological function of peroxisomes in MC3T3-E1 cell (osteoblast- like cell derived from mouse).Catalase activity was detected in the homogenate of MC3T3-E1 cells, suggested that peroxisomes were present in MC3T3-E1 cell. Other peroxisomal marker enzyme activities were not detected in the homogenate. Therefore, the proliferation of peroxisomes by clofibrate (peroxisomal proliferator) treatment and some peroxisomal enzyme activities must be investigated further.