Gender Specific Effects of Periapical Tooth Lesions on Adipose Tissues

Objectives: Our objective was to determine gender-specific responses to periapical tooth  lesions (PA) on the composition of omental adipose tissue in the rat.

Methods:

Female SD rats with (OVXF) and without (NF) ovariectomies and males with (CM) and without (NM) castration were studied (n=16 for each group).  In 1/2 of the animals, PA were created by opening the pulps of the maxillary molars to the oral cavity (Experimental group, E).  1/2 of the rats were sham-operated (C).  28 days later, the animals were weighed and serum and greater omentum were collected.  1/2 of each of the tissues were embedded in paraffin, and were serially sectioned and stained with H&E or with either anti-CRP or anti-TNF-α.  Using Sigma Scan Plus, the mean number of adipocytes, their cross-sectional area and volume fraction of lipid were assessed. ½ of the tissues were solubilized to assess leptin, IL-6, IL-1-β and TNF-α concentrations by ELISA. In addition, serum CRP, 17-β estradiol, and testosterone concentrations were determined by ELISA. Data were compared by factorial ANOVA and a post-hoc Tukey test. Differences were significant when p<0.05.  

Results: Body weight after 28 days was greater in OVXF-E than in all other female groups and lower in CM-E than in other male groups (p<0.05). Coincidently, adipose cellular cross-sectional area and volume fraction of lipid were both greater in OVXF-E than in the other groups (p<0.05).   Serum and omental leptin, IL-1-β, IL-6 and TNF-α concentrations were greater in OVXF-E than either NF-E or NF-C and all male groups (p<0.05).      

Conclusions: The data suggest that estrogen deficiency and presence of PA in females affect body weight by producing inflammation in adipose tissues and by increasing the size and lipid content of adipocytes, These effects were not evident in males. Thus, estrogen-deficient females may be at risk for systemic sequellae from PA.