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Effect of pentachlorophenol on calcium accumulation in barnacle muscle cells.
Author(s) -
Nwoga J C,
Sniffen J C,
Peña-Rasgado C,
Kimler V A,
Rasgado-Flores H
Publication year - 1996
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.1996.sp021192
Subject(s) - depolarization , tris , pentachlorophenol , chemistry , extracellular , biophysics , verapamil , membrane potential , calcium , biochemistry , biology , organic chemistry , environmental chemistry
1. The effect of extracellularly applied pentachlorophenol (PCP) was studied on the membrane potential (Vm) and Ca2+ uptake in isolated single skeletal muscle cells of Balanus nubilus. 2. When compared with the controls, 0.1 mM PCP induced a significant (P < 0.05) increase in Ca2+ uptake accompanied by membrane depolarization (9 mV at 45 min incubation). This depolarization was reduced by 11% of extracellular Ca2+ (Cao2+) was replaced by Tris+ and by 50% if extracellular Na+ was also replaced by Tris+. 3. The Ca2+ channel blocker, verapamil (0.1 mM), completely inhibited the PCP‐induced Ca2+ uptake as well as the membrane depolarization either in the absence or presence of Cao2+. Experiments on voltage‐clamped cells show that the PCP‐induced Ca2+ uptake was independent of the PCP‐induced depolarization. 4. The results indicate that PCP induces activation of a verapamil‐sensitive Ca2+ influx pathway (presumably L‐type Ca2+ channels) independent of Vm. The permeation of Ca2+, Na+ and Tris+ through this pathway produces membrane depolarization in the following order of effectiveness: Ca2+ > Na+ > Tris+.