1991 Fiscal Year Final Research Report Summary

Effects of Periodontic Restration of Periodontitis caused by Lipopolysaccharide Bacteria

Research Project

Project/Area Number	02670863
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Conservative dentistry
Research Institution	Fukuoka Detal College
Principal Investigator	HARAGA Yoshiaki Fukuoka Dental College Endodontics and Periodontics Lecturer, 歯学部, 講師 (10105702)
Project Period (FY)	1990 – 1991
Keywords	Lipopolysaccharide / Gingival mitochondria / Respiratory control
Research Abstract	Lipopolysaccharide (LPS) was extracted from Bacteroides gingivalis (B. g), which is thought to be one of the bacteria that causes periodontitis, and treated with liver and heart mitochondria. The effects were examined according to the ability of the mitochondria to respire. E. coli LPS was used as the control subject. Gingiva was extracted from a dog and the gingival mitochondria preparation was tested in order to find the effects on gingiva. The results are as follows : 1. When the liver mitochondria was treated with E. coli LPS at the ratio of 3Omug/mg, the ADP/0 ratio was 32.5% and the respiratory control ratio (RCR) declined by 36.2%. When treated with 40mug/mg of LPS, the mitochondria was completely unable to respire. 2. When the liver mitochondria was treated with B. g LPS at the ratio of 150mug/mg, the ADP/0 ratio was 35.5% and the RCR declined by 39.4%. When treated with 200mug/mg of LPS, the mitochondria was completely unable to respire. 3. When the heart mitochondria was treated with E. coli LPS at the ratio of 25mu/mg, the ADP/0 ratio was 20.0% and the RCR decreased by 20.6%. When treated with 50mug/mg of LPS, respiration was undetectable. 4. When the liver mitochondria was treated with B. g LPS at the ratio of 1, 000mug/mg, the ADP/0 ratio was 30.5% and the RCR was reduced by 44.1%. And resoiration was undetectable when treated with 1.500mug/mg of LPS. 5. When measuring the amount of oxygen depletion in the mitochondria prepared from gingiva, respiratory stroma was observed and an increase in the amount of oxygen depletion was detected when ADP was added ; however, after the ADP was expended, respiratory control was found to be unstable. Presently, the type, temperature and density of oxygen are being considered in order to prepare gingival mitochondria with respiratory control.