Alveolar bone loss in thymectomized golden hamsters.

Fifty-six neonatally thymectomized and 41 neonatally sham-operated female golden hamsters (Mesocricetus auratus) were divided into 2 groups, one inoculated with Actinomyces (N16) and the other not inoculated. All animals were raised and maintained on a high sucrose, soft diet (Diet 2000) and water, ad libitum. White blood cell counts, differentials and total lymphocyte counts were determined at 4 to 5 weeks of age. The rejection of albino hamster skin grafts and the hemagglutination response to sheep red blood cells (SRBC) were used to determine inhibition of T lymphocyte function. Evaluation of alveolar bone loss at the end of 160 days indicated that the thymectomized animals with a significant depression of the hemagglutination response to SRBC and a lack of skin graft rejections had a significantly higher bone loss than sham-operated animals. This suggests that the cellular immune response plays a role in the periodontal syndrome in hamsters. Further investigation is necessary to establish how significant this role is in relationship to the numerous other factors that are present. These data suggest that the role of the cellular immune response in the hamster periodontium may be protective rather than destructive. The role of Actinomyces (N16) in the development of bone loss was not significant.