Mechanism of recovery in esophageal epithelia of rats with severe zinc deficiency.

ABSTRACT

Forty-six rats fed a Zn-deficient diet for 18 days, were divided into three groups and treated with Zn-deficient diet (GI), a normal (Zn-adequate) diet (GII) or a pharmacological Zn therapy diet (GIII) for 3 days. For light and electron microscopy, samples were taken at times 0, 8, 12, 24 and 72 h after treatment. In treatment GI, at all times, all rats had esophageal parakeratosis. With treatment GII, there was a variable progression toward normalization of the epithelium at 12 and 24 h. At 72 h there was almost complete recovery of normal epithelium. In treatment GIII at 8 h, large, light cells in the basal layer were shown to be present between dark cylindrical cells, a finding which was transitionary and disappeared at 12 h. Also, a thin keratinized layer was observed above the granular layer at 12 h. Recovery had progressed at 24 h and was complete after 72 h. The results are discussed in terms of a potential role of Zn in the sequence of cytochemical events in epithelial differentiation.