减少外部钙或钠会刺激叶状石莼卵子中的钙内流。

Reduced external calcium or sodium stimulates calcium influx in Pelvetia eggs.

机构信息

Department of Biological Sciences, Purdue University, 47907, West Lafayette, IN, USA.

出版信息

Planta. 1977 Jan;136(2):153-8. doi: 10.1007/BF00396191.

PMID:24420320

Abstract

The effect of external calcium and sodium ion concentrations on the calcium fluxes on the Pelvetia fastigiata De Toni egg was measured. Decreasing external [Ca(2+)] greatly increased the permeability of the eggs to Ca(2+); at 1 mM external Ca(2+) this permeability was 60 times as great as it was at the normal [Ca(2+)] of 10 mM. Lowering the external [Na(+)] also increased Ca(2+) influx; at 2 mM Na(+), the Ca(2+) influx was 2-3 times as great as it was at the normal [Na(+)] if choline was used as a Na(+) substitute. Lithium was less effective as a Na(+) substitute in increasing Ca(2+) influx. The extra Ca(2+) influx in low [Na(+)] seemed to be dependent on internal [Na(+)]. The Ca(2+) efflux increased transiently and then declined in low Na(+) media.

摘要

测量了外部钙离子和钠离子浓度对 Pelvetia fastigiata De Toni 卵钙离子流的影响。降低外部 [Ca(2+)] 大大增加了卵对 Ca(2+)的通透性；在 1 mM 的外部 Ca(2+)下，这种通透性是正常 10 mM [Ca(2+)] 的 60 倍。降低外部 [Na(+)] 也会增加 Ca(2+)内流；在 2 mM 的 Na(+)下，如果用胆碱代替 Na(+)，Ca(2+)内流是正常 [Na(+)] 的 2-3 倍。锂作为 Na(+)替代物增加 Ca(2+)内流的效果较差。低 [Na(+)] 下的额外 Ca(2+)内流似乎依赖于内部 [Na(+)]。在低 Na(+)介质中，Ca(2+)外排会短暂增加，然后下降。