The Effects of Sialoadenectomy and Epidermal Growth Factor on Gingival Tissue in Rats: An Ultrastructural Study

Abstract

ABSTRACTSubmandibular salivary glands (SMGs) synthesize, accumulate and secrete a large amount of epidermal growth factor (EGF) in rats. EGF stimulates cell proliferation and differentiation by binding to its reseptors (EGFR).The aim of the present study was to mimic an endogenous epidermal growth factor deficiency through sialoadenectomy in paralel to exogenous EGF administration and to observe the ultrastructural changes in rat gingival tissue, employing electron microscopy.Thirty adult female Wistar albino rats were divided randomly into three groups: a control group (n:10), a sialoadenectomy group (n:10) and a sialoadenectomy group to which an EGF was administered (n:10).The experimental groups of rats were subjected to sialoadenectomy in order to create EGF deficiency. After 27 days both control and experimental rat groups were euthanized by pentobarbital and their gingival tissue was removed. Tissue samples from gingiva were processed for ultrastructural study.Electron microscopic evaluation indicated that while in the control group gingival tissues showed a normal appearance changes were observed in the experimental groups. We observed a partial degeneration of the epithelial cell junctions. Widespread crystolisis was also observed in a group of mitochondria.It is concluded that epidermal growth factor deficiency achieved by sialoadenectomy caused ultrastructural changes in gingival epithelium.