Phagocytosis of new cementum‐like islets formed inside the gingival connective tissue in cyclosporin‐A treated rats

Abstract

Three control and 3 experimental rats were administered vehicle or cyclosporin-A solutions. Animals were anaesthetized, tissues fixed and jaws processed for Epon inclusion. Histological examination of serially cut areas revealed the presence inside the gingival connective tissue of new cementum-like islets (NCLIs) associated to or engulfed by voluminous multinucleated cells (MCs). These complexes were located adjacent to blood vessels, at 250-350 microns from the root surface. Histomorphometric study indicated that the volume of the NCLIs varied from 3900 to 72,900 microns 3 and that of the MCs from 822 to 56,190 microns 3. The latter bore up to 14 nuclear profiles. Comparative evaluation of the NCLI-MC associations to other complexes "multinucleated cell(s)-resorbed material" seems to indicate that the phagocytosis of the NCLIs is dictated by their ectopic location, rather than their nature (new cementum-like structures). Therefore the MCs should be considered as foreign body giant multinucleated cells rather than cementoclasts.

Cyclosporin a-induced new cementum formation: a morphometric evaluation in the periapical region of rats

“…Various side effects associated with CsA treatment have been described, including nephropathy, hypertension, hepatotoxicity, neurotoxicity, hypertricosis and thromboembolic complications. It is well established that CsA causes gingival overgrowth, bone loss and induces cementum deposition (7)(8)(9)(10)(11)(12)(13)(14). It has been shown that CsA administrated orally to rats induces abundant new cementum formation with functionally inserting collagen fibers (12,13).…”