Histological Changes in Oral Mucosa in Zinc-Deficient Rats : Focusing on Periodontal Tissue

Abstract

It is well known that the inadequate intake of the essential trace element zinc (Zn) leads to a number of clinical symptoms, including growth retardation, decreased immunity, and gustatory abnormalities. However, many aspects of the expression mechanisms and Zn metabolism during Zn deficiency are still unknown. Therefore, the aim of this study was to investigate the effects of Zn deficiency on oral mucosa tissue, in particular periodontal tissue, by dividing twelve 4 week old male Wistar rats into 2 groups, a control group and a Zn deficient group, and rearing them for 3 weeks on special powder feed. The results showed that the increase in body weight in the Zn deficient group was more gradual than that in the control group; depilation in the abdominal and neck regions beginning about 2 weeks after starting the experiment, together with low serum Zn and serum ALP activity levels. Scanning electron microscopy revealed the accumulation of foreign bodies in the Zn deficient group and irregular morphology. Although light microscopy did not reveal any changes in periodontal tissues in the Zn deficient group in the present study, keratinization of the mucosal cortex in the palatal region and complex keratinization extending from the gingivobuccal fold region to the buccal mucosa were observed.