Postnatal glutamate‐induced central nervous system lesions alter periodontal disease susceptibility in adult Wistar rats

BACKGROUND: Inability to mount a suitable brain-neuroendocrine response to bacterial or other antigenic challenges has been found to play an important rôle in infectious and inflammatory disease susceptibility and progression, including periodontal disease. OBJECTIVE: The present study was designed to determine the effects of glutamate administration to new-born Wistar rats on the development and progression of naturally occurring and ligature-induced periodontal disease in the rats as adults. Postnatal glutamate administration is known to permanently damage neurones in the hypothalamic arcuate nucleus. METHOD: New-born rats were treated 1x daily subcutaneously with 2 mg/g of monosodium-L-glutamate (MSG) for 5 days from day 3 to 6. Control animals were injected with similar amounts of saline. Experimental ligature-induced periodontal disease was induced in the rats at the age of 12 weeks at maxillary right 2nd molar teeth. The contralateral maxillary left 2nd molars served as control teeth, and for assessment of naturally occurring periodontal disease. Disease progression was evaluated histometrically. RESULTS: The results revealed that the glutamate-lesioned rats developed significantly more periodontal tissue destruction compared to sham-lesioned control rats in both the ligated and non-ligated teeth. CONCLUSIONS: This study supports our recent findings indicating that inappropriate brain-neuroendocrine-immune regulation may play a rôle in periodontal disease susceptibility and progression.