An impurity in phenol red opens an ion channel in cultured human cells.
Human fibroblast, bladder carcinoma, and breast carcinoma cells in commercial serum-free media or balanced salt solutions rapidly lose K+ and gain Na+. This rapid K+ loss is caused by one or more impurities in phenol red. Adding serum or albumin to media or to balanced salts prevents K+ loss. Quinine also prevents part of this loss in fibroblasts and breast carcinoma cells, suggesting that the impurity acts on an ion channel.
Lubin
M
M
Department of Microbiology, Dartmouth Medical School, Hanover, New Hampshire 03755.
D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000648:ultrastructure; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D010637:Phenolsulfonphthalein / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D011471:Prostatic Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000648:ultrastructure; D011803:Quinine / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000473:pathology* / Q000503:physiopathology / Q000648:ultrastructure
D017077:Culture Media, Conditioned; D016895:Culture Media, Serum-Free; D007473:Ion Channels; D015221:Potassium Channels; D015222:Sodium Channels; D011803:Quinine; D010637:Phenolsulfonphthalein