Bregante Monica, Carpaneto Armando, Piazza Veronica, Sbrana Francesca, Vassalli Massimo, Faimali Marco, Gambale Franco
Institute of Biophysics, National Research Council of Italy (IBF), Genova, Italy.
Institute of Marine Sciences, National Research Council of Italy (ISMAR), Genova, Italy.
PLoS One. 2016 Dec 9;11(12):e0167972. doi: 10.1371/journal.pone.0167972. eCollection 2016.
We investigated the biophysical properties of the transport mediated by ion channels in hemocytes from the hemolymph of the bivalve Mytilus galloprovincialis. Besides other transporters, mytilus hemocytes possess a specialized channel sensitive to the osmotic pressure with functional properties similar to those of other transport proteins present in vertebrates. As chloride fluxes may play an important role in the regulation of cell volume in case of modifications of the ionic composition of the external medium, we focused our attention on an inwardly-rectifying voltage-dependent, chloride-selective channel activated by negative membrane potentials and potentiated by the low osmolality of the external solution. The chloride channel was slightly inhibited by micromolar concentrations of zinc chloride in the bath solution, while the antifouling agent zinc pyrithione did not affect the channel conductance at all. This is the first direct electrophysiological characterization of a functional ion channel in ancestral immunocytes of mytilus, which may bring a contribution to the understanding of the response of bivalves to salt and contaminant stresses.
我们研究了双壳贝类贻贝血淋巴中血细胞离子通道介导的转运的生物物理特性。除了其他转运蛋白外，贻贝血细胞还拥有一种对渗透压敏感的特殊通道，其功能特性与脊椎动物中存在的其他转运蛋白相似。由于在外部介质离子组成发生变化时，氯离子通量可能在细胞体积调节中起重要作用，我们将注意力集中在一种内向整流电压依赖性、氯离子选择性通道上，该通道由负膜电位激活，并因外部溶液的低渗透压而增强。浴液中微摩尔浓度的氯化锌对氯离子通道有轻微抑制作用，而防污剂吡啶硫酮锌对通道电导完全没有影响。这是对贻贝原始免疫细胞中功能性离子通道的首次直接电生理表征，这可能有助于理解双壳贝类对盐和污染物胁迫的反应。
