Effects of hyperthermia on intracellular chloride.
Hyperthermia induces transient changes in [Na+]i and [K+]i in mammalian cells. Since Cl- flux is coupled with Na+ and K+ in several processes, including cell volume control, we have measured the effects of heat on [Cl-]i using the chloride indicator, MQAE, with flow cytometry. The mean basal level of [Cl-]i in Chinese hamster ovary cells was 12 mM. Cells heated at 42.0 degrees or 45.0 degrees C for 30 min had about a 2.5-fold increase in [Cl-]i above unheated control values when measured immediately after heating. There was about a 3-fold decrease in [Na+]i under the same conditions, as measured by Sodium Green. The magnitude of the increase in [Cl-]i depended upon time and temperature. The [Cl-]i recovered in a time-dependent fashion to control values by 30 min after heating. When cells were heated at 45.0 degrees C for 30 min in the presence of 1.5 mM furosemide, the heat-induced [Cl-]i increase was completely blocked. Since furosemide inhibits the Na+/K+/2Cl- cotransporter, Cl- channels, and even Cl-HCO3 exchange, these ion transporters may be involved in the heat-induced increase in [Cl-]i.
Amorino
G P
GP
Department of Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Fox
M H
MH
D000818:Animals; D016466:CHO Cells; D002712:Chlorides / Q000378:metabolism*; D006224:Cricetinae; D005334:Fever; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D005665:Furosemide / Q000494:pharmacology; D006358:Hot Temperature; D007424:Intracellular Fluid; D007700:Kinetics; D009550:Nigericin / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D013997:Time Factors; D014220:Trialkyltin Compounds / Q000494:pharmacology
D002712:Chlorides; D005456:Fluorescent Dyes; D014220:Trialkyltin Compounds; C011559:tributyltin; D005665:Furosemide; D012964:Sodium; D009550:Nigericin; D011188:Potassium