抄録
The distribution and abundance of the calcium binding protein, calbindin D-28k immunoreactivity in the taste buds of circumvallate papillae and larynx were compared between normoxic and chronically hypoxic rats (10% O2 for 2 months). In the normoxic control rats, calbindin D-28k immunoreactivity was observed in the cells and fibers of the intragemmal region of the taste buds in the circumvallate papillae. In contrast, in the subgemmal region of the laryngeal taste buds, fibers but not cells were immunoreactive for calbindin D-28k. In chronically hypoxic rats, calbindin D-28k immunoreactive cells and fibers in the taste buds were decreased in the circumvallate papillae. In the laryngeal taste buds, the density of the subgemmal calbindin D-28k immunoreactive fibers in the chronically hypoxic rats was greater than in normoxic rats. It is considered that function of the laryngeal taste buds is different from that of the lingual taste buds, so that laryngeal taste buds may be involved in chemosensation other than taste. The altered density of calbindin D-28k immunoreactive cells and fibers in the lingual and laryngeal taste buds is a predominant feature of hypoxic adaptation, and chronic hypoxic exposure might change the chemical sensitivity of the circumvallate papillae and larynx through the regulation of intracellular calcium ion. [J Physiol Sci. 2007;57 Suppl:S212]
