Ito N, Shinohara M, Azuma Y, Mori M
J Periodontol. 1977 Apr;48(4):201-8. doi: 10.1902/jop.1977.48.4.201.
New strains of ODU plaque-susceptible and resistant rats have been developed starting from litter mating at our laboratory, in 1972. Those strains were selected and mated for further generations. ODU plaque-susceptible and resistant rats are those that show the presence or absence of plaque formation in their gingiva of lower incisors after they are fed a commercially available powder diet. Experiments were started when rats weighing 75 to 85 gm were about 5 weeks old being fed with 20 gm of a powder diet a day. Almost every 4 days, plaque formation was observed in terms of 5 degrees from zero to 4 degrees and body weight. As a result, plaque formation in plaque-susceptible and resistant rats clearly showed their quality in their 3rd generation. Those qualities will be further emphasized as the generation advances. In the 3rd generation of plaque-susceptible rats, no difference was found in growth between those ingested with a powder diet and those with a solid diet of the same ingredients. But in the first 2 months, male plaque-resistant rats of the 3rd generation grew more quickly than susceptible rats.
1972年，我们实验室从同窝交配开始培育出了对ODU菌斑敏感和耐受的新型大鼠品系。对这些品系进行了选育并逐代交配。ODU菌斑敏感和耐受大鼠是指在喂食市售粉状饲料后，其下切牙牙龈中出现或未出现菌斑形成的大鼠。当体重75至85克、约5周龄的大鼠每天喂食20克粉状饲料时，实验开始。几乎每4天，从0度到4度以5个等级观察菌斑形成情况并记录体重。结果，菌斑敏感和耐受大鼠的菌斑形成情况在第3代时清楚地显示出了它们的特性。随着代数增加，这些特性会进一步凸显。在第3代菌斑敏感大鼠中，喂食粉状饲料的大鼠和喂食相同成分固体饲料的大鼠在生长方面没有差异。但在最初的2个月里，第3代雄性菌斑耐受大鼠比敏感大鼠生长得更快。
