Foster J D, Getchell M L, Getchell T V
Department of Physiology and Biophysics, University of Kentucky, College of Medicine, Lexington 40536-0084.
Cell Tissue Res. 1992 Jan;267(1):113-24. doi: 10.1007/BF00318697.
An indirect gold-labeling method utilizing the lectin from Limax flavus was employed to characterize the subcellular distribution of sialic acid in glycoconjugates of the salamander olfactory mucosa. The highest density of lectin binding sites was in secretory vesicles of sustentacular cells. Significantly lower densities of lectin binding sites were found in secretory granules of acinar cells of both Bowman's and respiratory glands. Lectin binding in acinar cells of Bowman's glands was confined primarily to electron-lucent regions and membranes of secretory granules. In the olfactory mucus, the density of lectin binding sites was greater in the region of mucus closest to the nasal cavity than in that closest to the epithelial surface. At the epithelial surface, the density of lectin binding sites associated with olfactory cilia was 2.4-fold greater than that associated with microvilli of sustentacular cells or non-ciliary plasma membranes of olfactory receptor neurons, and 7.9-fold greater than non-microvillar sustentacular cell plasma membranes. Lectin binding sites were primarily associated with the glycocalyx of olfactory receptor cilia. The cilia on cells in the respiratory epithelium contained few lectin binding sites. Thus, sialylated glycoconjugates secreted by sustentacular cells are preferentially localized in the glycocalyx of the cilia of olfactory receptor neurons.
采用一种利用黄蛞蝓凝集素的间接金标记方法，来表征蝾螈嗅觉粘膜糖缀合物中唾液酸的亚细胞分布。凝集素结合位点的最高密度出现在支持细胞的分泌小泡中。在鲍曼腺和呼吸腺的腺泡细胞分泌颗粒中，发现凝集素结合位点的密度显著较低。鲍曼腺腺泡细胞中的凝集素结合主要局限于分泌颗粒的电子透明区域和膜。在嗅觉黏液中，最靠近鼻腔的黏液区域中凝集素结合位点的密度，高于最靠近上皮表面的区域。在上皮表面，与嗅纤毛相关的凝集素结合位点密度，比与支持细胞微绒毛或嗅觉受体神经元非纤毛质膜相关的密度高2.4倍，比非微绒毛支持细胞质膜高7.9倍。凝集素结合位点主要与嗅觉受体纤毛的糖萼相关。呼吸上皮细胞上的纤毛含有很少的凝集素结合位点。因此，支持细胞分泌的唾液酸化糖缀合物优先定位于嗅觉受体神经元纤毛的糖萼中。
