Eosinophils during developing periodontal disease of rats

Experimentally provoked gingival inflammation in rats presented eosinophils in the cellular infiltrate. Eosinophil numbers increased progressively to a peak at 30 days, and subsequently there was no quantitative alteration. Initially eosinophils were found in inflammed areas underneath the gingival epithelium and in later periods were more numerous in the deep corium among the collagen fibers. The extracytoplasmic granules were among the collagen fibrils and close to fibroblasts which phagocytosed collagen. It is suggested that eosinophils participate in the experimentally induced periodontitis in rats, and that they can act on the metabolism of rat gingival collagen.