title: [Nicotine regulates large conductance ca2+ activated K+ channels in rat coronary arterial smooth muscle cells].
abstract: OBJECTIVE
  The present study was to explore signaling mechanisms underlying nicotine-induced inhibition of large-conductance calcium-activated potassium channels (BK(Ca)).
  
  
  METHODS
  8 week male Wistar rats were divided randomly into saline group and nicotine group and received respectively injection with saline or nicotine (Sigma, Shanghai, China) at 2 mg/(kg x d) for 21 days. Coronary vascular smooth muscle cells were dissociated enzymatically. Dissociated smooth muscle cells were interfered with CPT-cAMP (100 micromol/L) or forskolin (10 micromol/L). The signal channel open dwell-time (To), close dwell-time (Tc) and open probability (Po) were recorded.
  
  
  RESULTS
  CPT-cAMP or forskolin significantly prolonged To, shorten Tc and increased Po in saline group (P < 0.01). But in nicotine group To, Tc and Po did not been changed.
  
  
  CONCLUSIONS
  This phenomenon may serve as a physiological mechanism that nicotine inhibits BK(Ca) channel activity to increase via cAMP/PKA-dependent pathway.
authors.affiliation: Yijishan Hospital of Wannan Medical School, Wuhu 241001, China. kong.dylan@yahoo.com.cn
authors.forename: Xiang-Quan
authors.initials: XQ
authors.lastname: Kong
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Yang
authors.forename: Jing-Han
authors.initials: JH
authors.lastname: Jiang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Wang
mesh_terms: D000818:Animals; D001158:Arteries / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism*; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction
chemical_list: D051036:Large-Conductance Calcium-Activated Potassium Channels; D009538:Nicotine