FSH aggravates periodontitis-related bone loss in ovariectomized rats

Alveolar bone loss is one of the prominent pathologic and clinical features of periodontitis. Recently, the direct effect of follicle-stimulating hormone (FSH) on bone resorption has been demonstrated. However, the effect of FSH on alveolar bone loss remains unknown. This study tested the hypothesis that FSH would exacerbate periodontitis-related alveolar bone loss. Experimental periodontitis was induced in ovariectomized rats, and the rats were treated with extrinsic FSH or its inhibitor, leuprorelin. After mandibles were collected, we performed morphological examinations to evaluate bone loss, enzyme histochemical tests for osteoclasts, and immunohistochemical examinations for FSH receptor (FSHR). The results showed that FSH significantly increased alveolar bone resorption compared with non-FSH-treated ovariectomized rats (P < 0.05), and the number of FSHR-positive cells was positively correlated with alveolar bone loss area (r = 0.682, P < 0.01). Our results suggested that FSH can aggravate alveolar bone loss by FSHR, independent of estrogen.