AQUAT TOXICOL:约克大学丨盐污染淡水对昆虫渗透调节和气管鳃功能的影响(Na+流,附NMT实验体系)
- 期刊:Aquatic toxicology
- 主题:盐污染淡水对昆虫渗透调节和气管鳃功能的影响(Na+流)
- 标题:Impact of salt-contaminated freshwater on osmoregulation and tracheal gill function in nymphs of the mayfly Hexagenia rigida
- 影响因子:3.884
- 检测指标: Na+流速
- 检测部位:气管鳃丝中心轴
- Na+流实验处理方法: 长约20mm的蜉蝣在FW(Freshwater)对照条件或SCW(Salt-contaminated water)处理7天
- Na+流实验测试液成份: 0.5mM NaCl,206.5mM N-甲基-D-葡糖胺(NMDG)
- 通讯作者:约克大学Andrew Donini、Fargol Nowghani
英文摘要
The impact of freshwater (FW) salinization on osmoregulation as well as tracheal gill morphology and function was examined in nymphs of the mayfly Hexagenia rigida following exposure to salt contaminated water (SCW, 7.25 g/l NaCl) for a 7-day period.
Ionoregulatory homeostasis was perturbed in SCW exposed H. rigida nymphs as indicated by increased hemolymph Na+, K+ and Cl− levels as well as hemolymph pH and water content. Despite this, SCW did not alter gill Na+-K+-ATPase (NKA) or V-type H+-ATPase (VA) activity. In addition, NKA and VA immunolocalization in gill ionocytes did not show alterations in enzyme location or changes in ionocyte abundance.
The latter observation was confirmed using scanning electron microscopy (SEM) to examine exposed tracheal gill ionocyte numbers. Ionocyte surface morphometrics also revealed that SCW did not change individual ionocyte surface area or ionocyte fractional surface area. Nevertheless, analysis of Na+ movement across the tracheal gill of mayfly nymphs using scanning ion-selective electrode technique indicated that FW nymphs acquired Na+ from surrounding water, while tracheal gills of SCW nymphs had the capacity to secrete Na+.
Because Na+ secretion across the gill of SCW-exposed animals occurred in the absence of any change in (1) NKA and VA activity or (2) ionocyte numbers/surface exposure, it was reasoned that Na+ movement across the gill of SCW animals may be occurring, at least in part, through the paracellular pathway. The ultrastructure of tracheal gill septate junctions (SJs) supported this idea as they exhibited morphological alterations indicative of a leakier pathway. Data provide a first look at alterations in osmoregulatory mechanisms that allow H. rigida nymphs to tolerate sub-lethal salinization of their surroundings.
中文摘要(谷歌机翻)
在暴露于盐污染的水(SCW,7.25g / l NaCl)7天后,在may fly(Hexflynia rigida)的若虫中检查淡水(FW)盐化对渗透调节以及气管鳃形态和功能的影响。
在SCW暴露的H. rigida若虫中扰乱了离子调节的体内平衡,如血淋巴Na+,K+和Cl-水平增加以及血淋巴pH和水含量所示。尽管如此,SCW没有改变鳃Na+ -K+ -ATP酶(NKA)或V型H+ -ATP酶(VA)活性。此外,鳃离子细胞中的NKA和VA免疫定位没有显示酶位置的改变或离子细胞丰度的变化。
使用扫描电子显微镜(SEM)确认后一观察结果以检查暴露的气管鳃离子细胞数。离子细胞表面形态测量也表明,SCW没有改变个体离子细胞表面积或离子细胞分数表面积。然而,使用扫描离子选择性电极技术分析穿过may may若虫的气管鳃的Na+运动表明FW若虫从周围水中获得Na+,而SCW若虫的气管鳃具有分泌Na+的能力。
因为在SCW暴露的动物的鳃上Na+分泌发生在(1)NKA和VA活性或(2)离子细胞数量/表面暴露没有任何变化的情况下,因此推测在SCW动物的鳃上Na+运动可能是至少部分地通过细胞旁路径发生。气管鳃隔膜交界处(SJs)的超微结构支持这一观点,因为它们表现出指示渗漏途径的形态学改变。数据首次提供了渗透调节机制的改变,这些改变使得H. rigida若虫能够耐受其周围环境的亚致死盐化。
结果表明,在RI至RVI六个不同区域,沿着蜉蝣的鳃在空间上检查Na+转运(图A)。在所测量的所有6个区域中,蜉蝣的鳃从周围的水中吸收Na+。在前4个鳃区域(RI-RIV)Na+吸收速率大于RV、RVI。相反,发现SCW蜉蝣的鳃在所检查的所有6个区域中分泌Na+,并且分泌速率的空间差异是显着的(图C),来自近端的前两个区域RI和RII比后4个区域的分泌速率要大很多。(图C)。
文章链接:https://www.sciencedirect.com/science/article/pii/S0166445X18310634?via%3Dihub