Premium
Measurement of potassium and chloride ion concentrations in the cupulae of the lateral lines of Xenopus laevis.
Author(s) -
Russell I J,
Sellick P M
Publication year - 1976
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1976.sp011366
Subject(s) - xenopus , toad , ouabain , biophysics , potassium , chemistry , anatomy , electrophysiology , chloride , sodium , biology , biochemistry , endocrinology , organic chemistry , neuroscience , gene
1. Potential measurements were made with double barrel ion selective electrodes from the cupulae of lateral line organs in the aquatic toad Xenopus laevis. 2. A positive endocupular potential (ECP) of 15‐50 mV was recorded within the cupula, immediately above the hair cells. 3. Increases in the Cl‐ and K+ potentials were recorded when the ion selective electrodes touched the cupula. Cupular Cl‐ and K+ varied between 35 and 70 mM and 24 and 100 mM respectively. This variation existed between, rather than within, different animals. 4. Subcutaneous injections of 0‐4 ml. 2 mM ouabain greatly reduced the ECP and cupular K+, whereas 0‐4 ml. of Xenopus Ringer had no effect. 5. Changing the bath Cl‐ a hundredfold had no effect on the ECP. It was concluded that the ECP was produced by an electrogenic K+ pump which maintained high K+ levels within the cupula.