Investigation of c-fos and preprodynorphin induced by noxicious stimulation on tooth

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671922
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: TOHOKU UNIVERSITY
• Principal Investigator: IGARI Toshirou Tohoku University, School of Dentistry Dental Hospital, Associate Professor, 歯学部附属病院, 助教授 (10142994)
• Co-Investigator(Kenkyū-buntansha): IWATSUKI Naofumi Tohoku University, Graduate School of Dentistry, Professor, 大学院歯学研究科, 教授 (50004908) ; MORI Shirou Tohoku University, School of Dentistry Dental Hospital, Lecturer, 歯学部附属病院, 講師 (80230069)
• Project Period (FY): 2000 – 2001
• Keywords: c-fos / noxiciou stimulant / tooth pain

Research Abstract

Most uncuarable pain in oral lesion occurred after chronic pulpitis or periodopntitis which present the symptom like the deafferention pain. So we start the research for c-fos, one of the cancer related gene, is known to present in the dorsal horn of the spinal cord and the special area of brain, as a new marker of those oral pain. Under light halothane anesthesia reveal a rat's upper jaw nerve (1)cut the upper jaw nerve (Model I), (2)Chronic constriction injury (CCI) model (Model II) (3)sealed with paraformaldehyde in rat's cisal tooth pulp, chronic pulpal tooth model (Model III)
Samples were taken each 30minite to 3hours, and each one week to 3 months.
After noxious stimulation, the numbers of the c-fos positive cell on the dorsal horn of C1 and C2 cervical cord, and trigeminal nucleus caudalis (TNC) were presented in the stimulated group. But it also revealed in the sham group. (p<0.001 ; between the all group at the same area).
These results don't indicate that the noxious stimulus induces the gene expression of c-fos on the dorsal horn and TNC.
The c-fos, therefore, is not useful biochemical index for the evaluation of pain expression on nerve level in our research.