Responses of periodontal nerve terminals to experimentally induced occlusal trauma in rat molars: an immunohistochemical study using PGP 9.5 antibody.
The response of periodontal nerves to experimentally induced occlusal trauma in rat molars was assessed by immunohistochemistry for protein gene product 9.5 (PGP 9.5) at light and electron microscopic levels, and by computerized image analysis. The occlusal surface on the left upper first molar of 8-wk-old male Wistar rats was raised approximately 1 mm under ether anaesthesia. The rats were perfusion-fixed on d 1, 2, 3, 4, and 7 after bite-raising and then decalcified for 2-3 wk. Frozen sagittal cryostat sections were stained by the avidin-biotin complex method. By the second day after bite-raising many Ruffini endings were swollen and their outline unclear at the light microscopic level. Transmission electron microscopy disclosed PGP 9.5 reaction products within Ruffini endings that had unusually long cytoplasmic projections extending through enlarged slits of the Schwann sheaths and also diffuse extracellular PGP 9.5-immunoreactivity near the Ruffini endings. From d 2 to 4, thin nerve fibres on the pressure side of the periodontal ligament were orientated irregularly and had a prominent beaded appearance. An increase in beaded nerve terminals occurred at d 2-4 post elevation, and decreased later. These results suggest that occlusal trauma indices specific changes in the distribution and shape of nerve terminals in the periodontal ligament.
Sodeyama
T
T
Department of Periodontology, Niigata University School of Dentistry, Japan.
Maeda
T
T
Takano
Y
Y
Hara
K
K
D000818:Animals; D000911:Antibodies, Monoclonal; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D003769:Dental Occlusion, Traumatic / Q000378:metabolism / Q000473:pathology*; D005109:Extracellular Matrix / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008465:Mechanoreceptors / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D008963:Molar; D009411:Nerve Endings / Q000378:metabolism / Q000648:ultrastructure*; D009412:Nerve Fibers / Q000378:metabolism / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000032:analysis*; D010513:Periodontal Ligament / Q000294:innervation*; D051381:Rats; D017208:Rats, Wistar; D012583:Schwann Cells / Q000378:metabolism / Q000473:pathology; D013869:Thiolester Hydrolases / Q000032:analysis*; D043222:Ubiquitin Thiolesterase
D000911:Antibodies, Monoclonal; D009419:Nerve Tissue Proteins; D013869:Thiolester Hydrolases; D043222:Ubiquitin Thiolesterase