title: Measuring Ca2+ influxes of TRPC1-dependent Ca2+ channels in HL-7702 cells with non-invasive micro-test technique.
abstract: OBJECTIVE
  To explore the possibility of using the Non-invasive Micro-test Technique (NMT) to investigate the role of Transient Receptor Potential Canonical 1 (TRPC1) in regulating Ca(2+) influxes in HL-7702 cells, a normal human liver cell line.
  
  
  METHODS
  Net Ca(2+) fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPC1 were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  Ca(2+) influxes could be elicited by adding 1 mmol/L CaCl(2) to the test solution of HL-7702 cells. They were enhanced by addition of 20 micromol/L noradrenaline and inhibited by 100 micromol/L LaCl(3) (a non-selective Ca(2+) channel blocker); 5 micromol/L nifedipine did not induce any change. Overexpression of TRPC1 caused increased Ca(2+) influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 micromol/L LaCl(3) did.
  
  
  CONCLUSIONS
  In HL-7702 cells, there is a type of TRPC1-dependent Ca(2+) channel, which could be detected via NMT and inhibited by La(3+).
authors.affiliation: Department of General Surgery, Digestive Medical Center, the First Affiliated Hospital, Medical School, Tsinghua University, Beijing 100016, China.
authors.forename: Zhen-Ya
authors.initials: ZY
authors.lastname: Zhang
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Wang
authors.forename: Li-Jie
authors.initials: LJ
authors.lastname: Pan
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
authors.forename: Zong-Ming
authors.initials: ZM
authors.lastname: Zhang
mesh_terms: D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology*; D002460:Cell Line; D006801:Humans; D007811:Lanthanum / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D050052:TRPC Cation Channels / Q000502:physiology*
chemical_list: D015220:Calcium Channels; D050052:TRPC Cation Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; D007811:Lanthanum; D009543:Nifedipine; D002118:Calcium; D009638:Norepinephrine