Reduction of type II taste cells correlates with taste dysfunction after X-ray irradiation in mice.
BACKGROUND
Taste dysfunction that develops after radiotherapy for head and neck cancer impairs patients' quality of life. Although taste cells have been shown to degenerate after exposure to X-ray irradiation, the alteration in taste cell population is unclear. This study investigated the histopathological change of taste bud structure and the taste cell population in X-ray irradiated mice.


METHODS
The head and neck region of C57BL/6J male mice was exposed to a single 15 Gy dose of X-ray irradiation and a chronological histopathological analysis of the circumvallate papilla was performed. Preference for sweet taste was measured using the two-bottle preference method.


RESULTS
The histological analysis of the circumvallate papilla revealed that the basal cells had almost disappeared, but that there was not clear change in the spindle-shaped taste cells on day 4 after irradiation. The number of taste cells had decreased on day 8, and then remained unchanged until day 20, after which they increased and recovered to their original number by day 24. There was a more marked decrease in the number of alpha-gustducin-positive type II taste cells than in the number of serotonin-positive type III taste cells. Preference for sweet taste measured by the two-bottle preference method was decreased in parallel with taste cell number.


CONCLUSIONS
These findings suggest that X-ray irradiation disrupts the basal cells, resulting in a decrease of the number of taste cells, particularly type II taste cells, which may be the cause of radiotherapy-induced taste dysfunction.
Yamazaki
M
M
Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Fujii
S
S
Ochiai
A
A
D000818:Animals; D002452:Cell Count; D004847:Epithelial Cells / Q000473:pathology / Q000528:radiation effects; D020962:Heterotrimeric GTP-Binding Proteins / Q000032:analysis / Q000528:radiation effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D009412:Nerve Fibers / Q000528:radiation effects / Q000648:ultrastructure; D021122:Protein Subunits / Q000032:analysis / Q000528:radiation effects; D011829:Radiation Dosage; D012684:Sensory Thresholds / Q000528:radiation effects; D012701:Serotonin / Q000032:analysis / Q000528:radiation effects; D013649:Taste / Q000528:radiation effects; D013650:Taste Buds / Q000473:pathology / Q000528:radiation effects*; D013651:Taste Disorders / Q000209:etiology*; D013997:Time Factors; D043222:Ubiquitin Thiolesterase / Q000032:analysis; D014965:X-Rays
D021122:Protein Subunits; D012701:Serotonin; D043222:Ubiquitin Thiolesterase; C496976:Uchl1 protein, mouse; C524407:GNAT3 protein, mouse; D020962:Heterotrimeric GTP-Binding Proteins