title: Store-operated calcium channels in HL-60 cells effects of temperature, differentiation and loperamide.
abstract: The effect of temperature on calcium release and influx has been compared in differentiated and undifferentiated HL-60 cells. Receptor-mediated release of intracellular calcium by ATP was little affected by temperature in HL-60 cells. In differentiated HL-60 cells the store-operated calcium (SOC) channel-dependent sustained elevation of calcium levels after ATP was maximal at 25-29 degrees C; at higher temperatures calcium levels returned relatively rapidly towards basal levels. In undifferentiated cells, a SOC channel-dependent sustained elevation of calcium levels was not observed with levels returning to basal levels much more rapidly than in differentiated cells. The initial thapsigargin-initiated elevation of calcium did not become maximal until about 25 degrees C in both differentiated and undifferentiated HL-60 cells. In differentiated cells, the SOC channel-dependent sustained elevation of calcium after thapsigargin was maximal at 30-37 degrees C, while in undifferentiated cells, the sustained elevation was maximal at 25-30 degrees C. Loperamide, which augments the SOC channel-dependent sustained elevation of calcium, showed a temperature-dependent response that was maximal at about 22 degrees C after either ATP or thapsigargin and was minimal at 37 degrees C. In contrast, inhibition of SOC channel-dependent elevation of calcium by miconazole or trifluoperazine was not greatly affected by temperature.
authors.affiliation: Laboratory of Bioorganic Chemistry, Bldg. 8, Rm. 1A17, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Harper
authors.forename: J W
authors.initials: JW
authors.lastname: Daly
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D008139:Loperamide / Q000494:pharmacology*; D013696:Temperature; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D004533:Egtazic Acid; D019284:Thapsigargin; D008139:Loperamide; D000255:Adenosine Triphosphate; D002118:Calcium