AN EXPERIMENTAL STUDY ON THE EFFECT OF THE DEMETHYLCHLORTETRACYCLINE ON MANDIBULAR SYMPHYSIS IN RATS

Demethylchlortetracycline이 백서 하악골결합부의 발육에 미치는 영향에 관한 실험적 연구

This study was undertaken to assess the effects of demethylchlortetracycline on bone growth of mandibular symphyseal region in rats. Demethylchlortetracycline at 30mg/kg body weight, respectively, were daily administered by mouth to the sewen female rats from 10th day of pregnancy to 13th day. Thirty six new-born rats from these experimental animals were used for histological examination at 1, 5, 10, 15, 20, 25 and 30 days. All these new-born rats were killed by an overdose of ether. Mandibular bodies were removed and fixed in $10\%$ neutral formalin,. Carney and aceton. Specimens were embedded, sectioned and stained with H-E, Van Gieson, PAS and prepared for alkaline phosphatase. The results were as follows; 1. Until erupting of incisors, hyaline cartilage was located in relatively large symphyseal space, but bone trabeculae of ossifying area at incisal side were arranged irregularly in experimental group. 2. During this period, PAS reaction was moderately positive, but alkaline phosphatase reaction was slightly positive. 3. By erupting or incisors, symphyseal space appeared narrower like control group, but alkaline phosphatase reaction tended to slow down. 4. By erupting of molars, symphyseal space appeared muck narrower, and cartilane plate was reduced and aealed off like control group. Alkaline phosphatase reaction tended to slow down severely.