Effects of Gender and Periapical Inflammation on the Rat Heart

Objective: The objective of this study was to compare the serum and cardiovascular tissue concentrations of tumor necrosis factor (TNF)-alpha between female and male rats with periapical tooth abscesses. Gender differences in the systemic response to these abscesses have not been reported, but have significant clinical significance.

Methods: 48 Sprague-Dawley rats were studied. They were divided into two groups: those with experimentally-induced periapical abscesses and sham-operated controls. To create the abscesses, the pulps of the first and second maxillary molar teeth were exposed using a ¼ round bur. Two weeks later, serum, the left half of the heart, and the great vessels were collected and immediately frozen. The tissue samples were ground in PBS containing a protease inhibitor (10 mg tissue/ml PBS/protease inhibitor). The total protein content of serum and tissue samples was determined using a bicinchoinic acid protein assay; the tissue and serum concentrations of TNF-alpha were determined by ELISA. Data was expressed as pg TNF-alpha/mg protein. The outcome variables were compared by factorial analysis of variance and a post-hoc Tukey test.

Results: Males with periapical abscesses had significantly greater TNF-alpha concentrations within the serum, heart and great vessels (p<0.05), as compared to females with periapical abscesses and sham-operated males. The females also had a treatment effect on the serum and tissue concentrations of TNF-alpha.

Conclusion: Male rats have a greater systemic response to periapical inflammation than females, suggesting that they might be at greater risk for systemic diseases featuring elevated concentrations of TNF-alpha (such as diabetes mellitus, type 2).

Acknowledgement: This study was supported by a University of Mississippi School of Dentistry Intramural Research Grant.