Dietary zinc deficiency decreases glutathione S-transferase expression in the rat olfactory epithelium.
Zinc deficiency leads to olfactory and gustatory dysfunction, but little is known about the underlying molecular mechanism of this phenomenon. We examined the effect of dietary zinc deficiency on the rat olfactory epithelium. Immunoreactivities of glutathione S-transferase (GST) mu, neuron-specific enolase (NSE) and proliferating cell nuclear antigen (PCNA), and in situ hybridization of GST mu mRNA in the olfactory epithelia were examined under different dietary zinc intake conditions. Adult male rats were fed a zinc-deficient (ZD) diet (0.5 mg zinc/kg diet), whereas control rats, including pair-fed (PF) and zinc-adequate (ad libitum consumption, AL) groups, were fed a zinc-adequate diet (58 mg zinc/kg diet) for 7 wk. We also examined the effect of zinc replacement (ZR) by subsequently feeding half of the ZD group a zinc-adequate diet for 5 wk after the initial 7-wk deprivation. No significant differences in immunoreactivity for NSE in olfactory epithelial receptor cells or for PCNA in basal cells were noted among groups. Intense GST mu immunoreactivity and hybridization signals were observed in olfactory supporting cells of AL, PF and ZR groups, but very minimal or no such signal was noted in ZD rats. Our findings indicated that zinc deficiency reduces GST mu expression in the supporting cells of rat olfactory epithelia but does not affect receptor cell proliferation or maintenance.
Kudo
H
H
Department of Anatomy, University of Occupational and Environmental Health, School of Medicine, Kitakyushu 807-8555, Japan.
Doi
Y
Y
Nishino
T
T
Nara
S
S
Hamasaki
K
K
Fujimoto
S
S
D000199:Actins / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D004435:Eating; D005982:Glutathione Transferase / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D009831:Olfactory Mucosa / Q000201:enzymology* / Q000473:pathology; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000008:administration & dosage / Q000097:blood / Q000172:deficiency*
D000199:Actins; D018809:Proliferating Cell Nuclear Antigen; D005982:Glutathione Transferase; D010751:Phosphopyruvate Hydratase; D015032:Zinc