Effects of zinc deficiency and supplementation on gene expression of bitter taste receptors (TAS2Rs) on the tongue in rats

Laryngoscope. 2012 Nov;122(11):2411-7. doi: 10.1002/lary.23378. Epub 2012 Oct 15.


Objectives/hypothesis: We examined the effect of zinc deficiency and supplementation on the expression of bitter taste receptor (TAS2R) and epithelial sodium ion channel (ENaC) genes on the tongue in rats.

Study design: Prospective animal study.

Methods: A total of 36 male Sprague-Dawley rats (3 weeks old) were used. Twelve rats were fed a normal diet for 28 (n = 6) or 56 (n = 6) days, another 12 were fed a zinc-deficient diet for the same periods, and still another 12 were fed a zinc-deficient diet for 28 days and then administered zinc for a further 28 days. The epithelium of the circumvallate papillae was collected, and expression of the TAS2R40, TAS2R105, TAS2R107, TAS2R118, TAS2R121, TAS2R136, TAS2R140, and ENaC genes was examined by reverse transcriptase-polymerase chain reaction.

Results: Gene expression frequency of TAS2R40 and TAS2R107 significantly decreased in rats fed a zinc-deficient diet, and frequency of TAS2R107 significantly increased following zinc administration. No changes were noted in expression of TAS2R105, TAS2R118, TAS2R121, or ENaC in zinc-deficient rats.

Conclusions: Our findings suggest that zinc may affect gene expression for some TAS2Rs on the tongue in rats.

MeSH terms

  • Animals
  • Epithelial Sodium Channels / genetics
  • Gene Expression*
  • Male
  • Prospective Studies
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, G-Protein-Coupled / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Taste / genetics*
  • Tongue
  • Zinc / administration & dosage
  • Zinc / deficiency*


  • Epithelial Sodium Channels
  • Receptors, G-Protein-Coupled
  • taste receptors, type 2
  • Zinc