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Conductance rise induced by the calcium ionophore A23187 in unfertilized eggs of tilapia
Author(s) -
House CR
Publication year - 1991
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.1991.sp003531
Subject(s) - ionophore , conductance , depolarization , membrane potential , tilapia , calcium , biophysics , voltage clamp , reversal potential , chemistry , membrane , patch clamp , electrophysiology , biology , fish <actinopterygii> , biochemistry , fishery , neuroscience , mathematics , organic chemistry , combinatorics
Current‐clamp measurements on unfertilized tilapia eggs gave linear current‐voltage relations in the range 0 to ‐120 mV. Eggs had low resting potentials (‐22 mV) and high specific membrane resistances (500 k omega cm2) and specific membrane capacitances (0.9 microF cm‐2) indicating no marked folding of their plasma membrane. Application of A23187 induced a small depolarization and a conductance rise, the response having a reversal potential of about ‐16 mV. The results suggest that tilapia eggs have a calcium‐gated conductance probably activated at fertilization.