Fukuda S, Matsuoka O
Jikken Dobutsu. 1979 Jan;28(1):1-9. doi: 10.1538/expanim1978.28.1_1.
The maturation process from the appearance to the fusion of the secondary ossification centers of extremities was studied in Wistar rats aged 0 to 134 weeks. The examination of the secondary ossification centers made by radiography. The assessment of the stage of development was made in accordance with the criteria proposed by Ohwada and Sutow. The secondary ossification center was found to be take one of the following three types of maturation processes : (1) the acute ossification, (2) the delayed ossification, and (3) the incomplete ossification. No fusion was observed up to 134 weeks in certain epiphyses of the rat. This type of ossification designated as the incomplete ossification may be specific to the mouse and rat. The relative lengths of time required for appearance and fusion in the average prospective life were obtained for the rat. They were compared with those of the mouse and man. The relative length of time necessary for maturity of the secondary ossification centers was shown to be the shortest in the rat and the longest in man. The results suggested that the rat may reach maturity in the bone age at 17 to 21 weeks of age. The rat at this age may be regarded as being adult corresponding to age 17 weeks in mice and 18 to 24 years in man.
对0至134周龄的Wistar大鼠四肢次级骨化中心从出现到融合的成熟过程进行了研究。通过X线摄影检查次级骨化中心。根据Ohwada和Sutow提出的标准对发育阶段进行评估。发现次级骨化中心呈现以下三种成熟过程之一：（1）急性骨化，（2）延迟骨化，（3）不完全骨化。在大鼠的某些骨骺中，直至134周都未观察到融合。这种被称为不完全骨化的骨化类型可能是小鼠和大鼠特有的。得出了大鼠在平均预期寿命中出现和融合所需的相对时间长度。将它们与小鼠和人类的进行了比较。结果表明，次级骨化中心成熟所需的相对时间长度在大鼠中最短，在人类中最长。结果提示，大鼠可能在17至21周龄时达到骨龄成熟。这个年龄的大鼠可被视为相当于小鼠17周龄和人类18至24岁的成年个体。
