Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand,
J Comp Physiol B. 2014 May;184(4):415-23. doi: 10.1007/s00360-014-0818-z. Epub 2014 Mar 7.
The element composition of the pseudocoelomic fluid of the Antarctic nematode Panagrolaimus davidi was analysed by electron probe X-ray microanalysis after absorbing the fluid into Sephadex G-25 beads, and after producing calibration curves by analysing various concentrations of elements of interest absorbed into beads. The nematodes maintain higher concentrations of sodium and potassium in their pseudocoelomic fluid than in the external medium but lower concentrations of magnesium and calcium. When external concentrations of specific ions were elevated there was evidence for the regulation of internal concentrations of sodium, potassium, magnesium and chlorine. The time course of changes in response to exposure to elevated levels of KCl shows an increase in internal concentrations of potassium and chlorine up to 2 h after exposure, followed by a decline. This is consistent with a model of ionic regulation proposed for Caenorhabditis elegans which suggests that high concentrations of ionic osmolytes are replaced by compatible organic osmolytes.
采用电子探针 X 射线微量分析方法，用葡聚糖凝胶 G-25 珠吸收潘氏线虫（Panagrolaimus davidi）的假体腔液，再用标准曲线法分析各种浓度的感兴趣元素被珠吸收后的情况，对潘氏线虫假体腔液的元素组成进行了分析。与外界介质相比，潘氏线虫的假体腔液中保持着更高浓度的钠和钾，但镁和钙的浓度则较低。当特定离子的外部浓度升高时，就有证据表明会对内部的钠、钾、镁和氯浓度进行调节。暴露于高浓度 KCl 后，钾和氯内部浓度的时间变化过程表明，暴露后 2 小时内，钾和氯的内部浓度增加，随后下降。这与为秀丽隐杆线虫（Caenorhabditis elegans）提出的离子调节模型一致，该模型表明，高浓度的离子渗透物被兼容的有机渗透物所取代。
