Exp Cell Res 1989 Aug 01;1832:343-52. doi: 10.1016/0014-4827(89)90395-9.

K+ activity and regulation of intracellular pH in the sea urchin egg during fertilization.

Abstract
Fertilization of the sea urchin egg is accompanied by changes in intracellular ion activities and transmembrane fluxes, which regulate the sequence of biochemical events of metabolic derepression. Changes in intracellular K+ activity during fertilization have been controversial and here we report our measurements using intracellular K+-sensitive microelectrodes. A small, but statistically significant, transient rise in internal K+ activity was detected during the first 10 min of fertilization. Since this change in K+ activity was ouabain sensitive, intracellular K+ activity in the fertilized egg appears to be regulated by the increased Na+, K+ ATPase activity, rather than the previously suggested K+ decompartmentalization. Increasing external K+ concentration was found to stimulate ouabain-sensitive alkalinization in the fertilized egg. The data are consistent with the possibility that Na+, K+ ATPase may regulate cytoplasmic pH by recycling Na+ that enters the cell through Na+-H+ antiport.

PubMed ID: 2548885
Article link: Exp Cell Res


Genes referenced: LOC100887844 LOC115919910 LOC581395