Fertilization of the sea urchin egg triggers a sequence of events that are necessary for metabolic derepression and stimulation of proliferation. Changes in intracellular Ca2+ and H+ activities regulate the sequence of events. Intracellular sodium activity is important in the regulation of the intracellular activities of these ions and may directly regulate metabolic events. Using Na+-sensitive microelectrodes we continuously measured the intracellular Na+ activity during fertilization. The results show an increase in intracellular sodium activity medicated by two pathways of Na+ entry: Na+ permeability increase during the fertilization potential and initiation of Na+-H+ exchange activity. Intracellular Na+ activity returned to unfertilized levels by 20 min after fertilization. This decrease was inhibited by ouabain, which suggests the activation of Na+, K+ ATPase during fertilization.
Article| August 01 1985
Intracellular sodium activity in the sea urchin egg during fertilization.
S S Shen
L J Burgart
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1985) 101 (2): 420–426.
S S Shen, L J Burgart; Intracellular sodium activity in the sea urchin egg during fertilization.. J Cell Biol 1 August 1985; 101 (2): 420–426. doi: https://doi.org/10.1083/jcb.101.2.420
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