[A study on erythrocyte-membrane osmotic resistance and periodontal changes in rats treated with carbon tetrachloride].

The objective of this study is to find correlation between erythrocyte-membrane osmotic resistance and periodontal changes. The hepatic function, chemical blood findings, and gingival changes including color, flow of gingival fluid, and local histological changes were studied in rats that had been treated with carbon tetrachloride. Results 1. Rats treated with carbon tetrachloride showed such changes in internal conditions as the following: mild inflammatory alterations, tendency to anemia, severe liver-cell injury, and liver dysfunction. 2. These changes affected the findings of erythrocyte-membrane osmotic resistance and the CPC hemolysis curve pattern. Both the hemolysis maximum point and the hemolysis end point were in the hypotonic side in the group treated with carbon tetrachloride. The maximum point of the CPC hemolysis curve pattern was also in the hypotonic side and not in the middle. 3. In male rats treated with carbon tetrachloride, while erythrocyte-membrane osmotic resistance was changing, round cells infiltrated into the tunica propria next to the epithelium in interdental papillae. Proliferation of the junctional epithelium in the direction of the root apex and hypertrophy in the lateral direction were also observed. These findings indicate mild inflammatory changes in the gingival tissues of the group that had been treated with carbon tetrachloride. Changes in internal conditions of rats treated with carbon tetrachloride affected alterations of erythrocyte-membrane osmotic resistance. Concurrent with these changes, slight inflammatory alterations occurred in the periodontal tissue.