Ionic selectivity of chloride ion symport in mechanisms controlling resting potential and osmotic homeostasis in earthworm somatic muscle cells.
Replacement of Cl(-) for Br(-) in bathing solution did not reduce resting potential and had no effect on modulation of transmembrane potential in hyper- and hypoosmotic solutions. Under these conditions, baclofen, an agonist of GABAergic B-type receptors, failed to activate Na(+)/K(+)-pump in earthworm somatic muscle cells. It was hypothesized that the contribution of Cl(-) symport to osmotic homeostasis is not highly selective in respect to replacement of Cl(-) to Br(-) ions, whereas in case of activation of electrogenic ion pumps, this replacement is equivalent to removal of Cl(-) ions from the bathing solution.
Volkov
E M
EM
Kazan State Medical University, Federal Agency for Health Care and Social Development, Russia. emvolkov@kzn.ru
Volkov
M E
ME
Zefirov
A L
AL
D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D001965:Bromides / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D018755:GABA Agonists / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects; D017136:Ion Transport / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D032342:Muscle Cells / Q000187:drug effects / Q000378:metabolism*; D009835:Oligochaeta / Q000166:cytology / Q000378:metabolism*; D009995:Osmosis / Q000187:drug effects; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000494:pharmacology
D001965:Bromides; D002712:Chlorides; D018755:GABA Agonists; D049994:Sodium Potassium Chloride Symporter Inhibitors; D005665:Furosemide; D001418:Baclofen