1993 Fiscal Year Final Research Report Summary
STUDIES ON THE MECHANISM OF ENDOTOXIN-INDUCED MICROIRCULATORY DISTURBANCE IN DENTAL PULP TUSSUE
| Project/Area Number |
04671121
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Functional basic dentistry
|
|---|
| Research Institution | Health Sciences University of Hokkaido (1993)
Tohoku University (1992) |
|---|
Principal Investigator |
HIRAFUJI Masahiko Health Sciences University of Hokkaido, FACULTY OF PHARMACEUTICAL SCIENCES, 薬学部, 助教授 (20142987)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SHINODA Hisashi ASSOCIATE PROFESSOR TOHOKU UNIVERSITY, SCHOOL OF DENTISTY, PROFESSOR, 歯学部, 教授 (80014025)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Keywords | Endotoxin / Dental pulp / Microcirculatory disturbance / Ischemia / Lipid peroxides / Adenine mucleotides |
|---|
| Research Abstract |
The aim of the present research project was to investigate the effect of systemic administration of endotoxin on the tissue injury of rat dental pulp, and to clarify its mechanism by pharmaclogical and histological studies. The intravenous advinistration of ecdotoxin (lipopolysaccharide of E.coli 0111 : B4) to the rat caused an increase in the cantent of lipid peroxides in the dental pilp, suggesting that endotoxin induced the microcirculatory disturbance. Since endotosin had no effect in the lung and intestinal tissues, dental pulp was more susceptible to endotoxic shock tan tese tissues. The increase of lipid peroxides in the pulp tissue was attributable to ischemic injury or leulocyte infiltration in the pulp tissue. When adenine nucleotides in the pulp tissue of the rat treated with endotoxin was analyzed by HPLC, AMP increased and ATP decreased aignificantly. Histological study revealed that endotoxin caused deformation of nuclei of pulp cells. However, inflammatory responses such as leukocyte infiltration or vasodilatation waer not observed. These results suggest that systemic administration of endotoxin to the rat induces ischemic tissue injury int he dental pulp. In the present study the mechanism of leukocyte-induced platelet adhesion to endothelial cells in vitro was also investigated. It was shown that the platelet adhesion was accompanied by a decrease in platelet cGMP platelet cGMP but not cAMP production is partially involved in the mechanism of leulocyte-induced platelet adhesion.
|
Research Products
(10 results)
