title: [Store-operated Ca2+ channels in rat colonic smooth muscle cells].
abstract: OBJECTIVE
  To study whether store-operated Ca2+ channel (SOC) is present in rat colonic smooth muscle cells.
  
  
  METHODS
  Intracellular Ca2+ ([Ca2+]i) changes induced by thapsigargin- or caffeine-activated SOC channel were measured in enzymatically dissociated rat colonic smooth muscle cells with the fluorescent indicator Fura-2/AM.
  
  
  RESULTS
  In the absence of external Ca2+ , the sarco-endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (1 micromol/L) and ryanodine receptor (RyR) activator caffeine both transiently elevated [Ca2+]i from (68.32 +/- 3.43) nmol/L to (240.85 +/- 12.65 ) nmol/L, (481.25 +/- 34.77) nmol/L. A subsequent reintroduction of Ca2+ into the extracellular solution resulted in [Ca2+]i further elevated to (457.55 +/- 19.80) nmol/L, (1005.93 +/- 54.62) nmol/L; (643.88 +/- 34.65) nmol/L, (920.16 +/- 43.25) nmol/L, respectively. And the elevated response was blocked by lanthanum (1 mmol/L), but was insensitive to L-type voltage calcium channels blocker verapamil and membrane depolarization.
  
  
  CONCLUSIONS
  SOC activated by store depletion are present in rat colonic smooth muscle cells. And we further prove the existence of such Ca2+ channels in excitable cells.
authors.affiliation: Laboratory of Neurophysiology, Department of Physiology, Anhui Medical University, Hefei 230032, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.forename: De-Hu
authors.initials: DH
authors.lastname: Kong
authors.forename: Rong
authors.initials: R
authors.lastname: Ma
authors.forename: Dao-Ping
authors.initials: DP
authors.lastname: Ke
authors.forename: Jin-Lan
authors.initials: JL
authors.lastname: Hu
authors.forename: Jie
authors.initials: J
authors.lastname: Song
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology*; D003106:Colon / Q000166:cytology; D016257:Fura-2 / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D015220:Calcium Channels; D002110:Caffeine; D019284:Thapsigargin; D002118:Calcium; D016257:Fura-2