title: [In vitro proliferation of rat Leydig cells].
abstract: OBJECTIVE
  To investigate the feasibility of in vitro proliferation of rat Leydig cells by modifying the cell culture system.
  
  
  METHODS
  Leydig cells were isolated from three-week-old rats by a procedure combining collagenase dispersion, stainless steel mesh infiltration and differential adhesion. The isolated cells were cultured in DMEM/F12 and modified media for stem cell proliferation, and the proliferation of the cultured cells was evaluated by cell counting and MTP test. The expression of 3beta-HSD in the cultured cells was detected by immunohistochemistry and flow cytometry, and testosterone productivity in the isolated Leydig cells with or without hCG stimulation was determined at 2 hours and 4 days after cell isolation.
  
  
  RESULTS
  The Leydig cells cultured in the modified media proliferated actively, with a doubling time of (2.26 +/- .31) days, as compared with (16.32 +/- 2.14) days for those cultured in the traditional media (P <0.05). The 3beta-HSD positive rate in the cultured cells was (554.3 +/- 7.1)% after 2 hours and (93.6 +/- 4.6)% after 4 days of culture. All the proliferated cells exhibited testosterone productivity, and their testosterone secretion was significantly upregulated by hCG stimulation (P <0.05).
  
  
  CONCLUSIONS
  Leydig cells isolated by differential adhesion proliferate actively in the modified culture media.
authors.affiliation: Department of Plastic Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China. bihongda0411@yahoo.com.cn
authors.forename: Hong-da
authors.initials: HD
authors.lastname: Bi
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Wang
authors.forename: Guang-dong
authors.initials: GD
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Xing
mesh_terms: D000818:Animals; D002452:Cell Count; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D007985:Leydig Cells / Q000166:cytology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013739:Testosterone / Q000378:metabolism
chemical_list: D013739:Testosterone