Katz U, Zaccone G, Fasulo S, Mauceri A, Gabbay S
Department of Biology, Technion, Israel Institute of Technology, Haifa, Israel.
Biol Cell. 1997 May;89(2):141-52.
Seven lectins were employed to localize glycoconjugates in the skin of a toad (Bufo viridis). Each of the lectins exhibited a particular, specific and selective binding pattern. Peanut lectin (PNA) and WGA bound to mitochondria-rich (MR) cells, but WGA bound also abundantly, in the dermis. Band 3-like protein, as indicated by the reaction with polyclonal anti band 3 antibody, was localized exclusively in MR cells. Ionic acclimation (200 mmol/L NaCl, or 50 mmol/L KCl) affected profoundly the binding pattern of the lectins. High NaCl acclimation resulted also in diminishing anti band 3 antibody binding, whereas in skins of KCl-acclimated toads the staining remained similar to the control. The binding of WGA but not PNA, corresponded with the same cells that stained with anti band 3 antibody. PNA in concentration of > 10 micrograms/mL reduced reversibly, both the resting and activated Cl- conductance by 25-30%. Based on differential binding of band 3, WGA and PNA, these observations provide conclusive verification of the presence of at least two populations of MR cells in the toad skin epithelium. It is suggested that the PNA positive MR cells may correspond to a beta-type MR cell. The information can be used to study molecular mechanisms that are involved in ionic acclimation.
使用七种凝集素来定位蟾蜍（绿蟾蜍）皮肤中的糖缀合物。每种凝集素都表现出特定、特异且选择性的结合模式。花生凝集素（PNA）和小麦胚芽凝集素（WGA）与富含线粒体的（MR）细胞结合，但WGA在真皮中也有大量结合。与多克隆抗带3抗体反应所表明的带3样蛋白仅定位于MR细胞中。离子驯化（200 mmol/L NaCl或50 mmol/L KCl）深刻影响了凝集素的结合模式。高NaCl驯化也导致抗带3抗体结合减少，而在KCl驯化的蟾蜍皮肤中，染色与对照相似。WGA而非PNA的结合与用抗带3抗体染色的相同细胞相对应。浓度>10微克/毫升的PNA可逆地使静息和激活的Cl-电导降低25-30%。基于带3、WGA和PNA的差异结合，这些观察结果确凿地证实了蟾蜍皮肤上皮中至少存在两种类型的MR细胞。有人提出，PNA阳性的MR细胞可能对应于β型MR细胞。该信息可用于研究参与离子驯化的分子机制。
