Cell death of taste buds in the circumvallate papillae after section of the glossopharyngeal nerves.

用DNA缺口末端标记法（TUNEL）结合标准电镜观察了切断双侧舌咽神经和秋水仙碱（微管去聚合诱导剂）处理后小鼠轮廓乳头味蕾中凋亡细胞的变化。去神经后3-11天，味蕾数量和大小减少，11天后消失。TUNEL法显示正常小鼠味蕾中仅有少数阳性染色核，但去神经后1-5天，阳性核数增加到正常小鼠味蕾的3-5倍。电子显微镜观察表明，味蕾细胞在细胞质中含有密度增加的编码和碎片的核。秋水仙素处理15 h和1 d后，味蕾细胞中出现大量TUNEL阳性细胞核，细胞核浓缩、破碎，表明正常条件下的味蕾细胞在其寿命末期以凋亡方式死亡，而切断味觉神经和秋水仙素处理可引起味蕾细胞凋亡。

Apoptotic cells in the taste buds of mouse circumvallate papillae after the sectioning of bilateral glossopharyngeal nerves and the treatment with colchicine (inducer of microtubules depolimerization) were examined by the method of DNA nick-end labeling (TUNEL), together with standard electron microscopy. The taste buds decreased in number and size 3-11 days after denervation and disappeared at 11 days. The TUNEL method revealed only a few positively stained nucliei in normal taste buds but, in those of mice 1-5 days after denervation, the number of positive nuclei had increased to 3-5 times that of taste buds from normal mice. Electron-microscopic obsevation after denervation demonstrated taste bud cells containing codensed and fragmentary nuclei in a cytoplasm with increased density. The colchicine treatment after 15 hours and 1 day showed many TUNEL-positive nuclei and the condensed and fragmentary nuclei in the taste bud cells.The results show that taste bud cells under normal conditions die by apoptosis at the end of their life span, and that gustatory nerve sectioning and colchicine treatment cause apoptosis of taste bud cells.