Electron microscopic studies on the cytoskeleton of taste buds.

在dd-MICE的环状乳突中，观察了由微管、5 nm细丝和10 nm细丝组成的味蕾细胞骨架。用秋水仙碱诱导微管去极化后，I型细胞的分泌颗粒被阻断，不能运输到根尖表面。单胺前体(5-HTP)和秋水仙碱处理均可延缓III型细胞的消失，并阻断III型细胞核心小泡向突触区域的运输。2.肌动蛋白免疫染色阳性反应定位于味蕾顶端。电子显微镜观察发现，在顶端突起和每个细胞的微绒毛中都有一束5 nm的细丝。在与重汞(HMM)孵育后，观察到这些细丝上有典型的箭头结构。结果表明，5 nm长丝由F-肌动蛋白组成。与周围的上皮细胞相比，味蕾细胞具有较少的密集聚集的10 nm细丝束。然而，III型细胞比I型或II型细胞含有更密集的聚集束。角蛋白的抗体形成皮肤，染色的所有类型的味蕾细胞以及周围的上皮细胞。结果表明，所有组成味蕾的细胞类型都起源于味蕾周围的上皮细胞。一种抗45kD角蛋白的单抗(PKK3)，通常位于单纯上皮细胞中，染色的是味蕾细胞，而不是周围的上皮细胞。

The cytoskeleton of taste buds composed of microtubules ,5-nm filaments, and 10-nm filaments was studied in the circumvallate papillae of dd-mice.1. After administration of colchicine which induces depolimerization of microtubules, the secretory granules of type-I cells were interrupted those transport to the apical surface. The treatment with both the monoamine precursor (5-HTP) and colchicine caused the delay of the disappearance of fluorescent type-III cells, and interrupted the transport of cored vesicles of type-III cells to synaptic areas.2.A positive reaction to immunostaining for actin were localized in the apical portion of the taste buds. Electron microscopic observations revealed a bundle of 5-nm filaments in the apical processes and microvilli in each cell. After incubation with heavy meromyoshin(HMM), characteristic arrowhead structures were observed along those filaments. It is concluded that 5-nm filaments are composed of F-action.3. Taste bud cells possessed less densely aggregated bundles of 10-nm filaments than the surrounding epithelial cells. Type-III cells, however, contained more densely aggregated bundles than type-I or -II cells. The antibodies to keratins form the skin stained all types of the taste bud cells as well as the surrounding epithelial cells. The result shows that all cell types comprising the taste buds originate from the epithelial cells surrounding the taste buds. A monoclonal antibody (PKK3) to a 45-kD keratin, which generally located in simple epithelia, stained taste bud cells, but not surrounding epithelial cells.