title: [Primary cultured neonate rat sinus node cells: morphology and expression of kir2.1 protein].
abstract: OBJECTIVE
  To investigate the expression of kir2.1 protein in primary cultured sinus node cells and establish a reliable technique to locate, culture and characterize neonatal rat sinus node cells.
  
  
  METHODS
  In paraffin sections, the location and morphology of the neonatal rat sinus node cells were observed by HE staining, silver nitrate staining, myelin staining and phosphotungstic acid-hematoxylin (PTAH) staining. Primary cell culture from the neonatal rat sinus node was conducted to observe the spontaneous contraction frequency, cell morphology and kir2.1 protein expression.
  
  
  RESULTS
  Combination of the 3 staining methods allowed accurate localization of the sino-atrial nodal (SAN) tissue, and among the cultured cells in the SAN, at least 3 distinct types of cells with spontaneous contraction were observed. The majority of the contracting cells were spindle cells and their construction and impulse frequency indicated their identity as pacemaker cells, while the triangular and irregular cells resembled the atrial muscle cells. A lower expression level of kir2.1 protein was detected in SAN cells than in the atrial and ventricular myocytes of the neonatal rats.
  
  
  CONCLUSIONS
  Combination of silver nitrate staining, myelin staining and PTAH staining identifies the exact location of the sinus node tissue, and cultured sinus node cells have lower expression of kir2.1 protein than the atrial and ventricular myocytes of neonatal rats.
authors.affiliation: Department of Cardiothoracic Surgery, Second Affiliated Hospital, Sun Yat-sen University, Guangzhou 510120, China. Weiyip2000@sina.com.cn
authors.forename: Yi-ping
authors.initials: YP
authors.lastname: Wei
authors.forename: Jin-guo
authors.initials: JG
authors.lastname: Zhu
authors.forename: Hui-zhong
authors.initials: HZ
authors.lastname: Zhang
authors.forename: Rui-wen
authors.initials: RW
authors.lastname: Xie
authors.forename: Ping
authors.initials: P
authors.lastname: Hua
authors.forename: Li-hua
authors.initials: LH
authors.lastname: Xiong
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012849:Sinoatrial Node / Q000166:cytology* / Q000378:metabolism
chemical_list: C489461:Kir2.1 channel; D024661:Potassium Channels, Inwardly Rectifying