title: The changes of stage distribution of seminiferous epithelium cycle and its correlations with Leydig cell stereological parameters in aging men.
abstract: OBJECTIVE
  To evaluate the changes of stage distribution of seminiferous epithelium cycle and its correlations with Leydig cell stereological parameters in aging men.
  
  
  METHODS
  Point counting method was used to analyze the stereological parameters of Leydig cells. The stage number of seminiferous epithelium cycle was calculated in the same testicular tissue samples which were used for Leydig cell stereological analysis.
  
  
  RESULTS
  The aging group had shown more severe pathological changes as well as higher pathologic scores than the young group. Compared with the control group, the volume density (VV) and surface density (NA) of Leydig cells in the aging group were increased significantly. The stage number of seminiferous epithelium cycle in the aging group was decreased coincidently compared to the young group. Leydig cell Vv in the young group has a positive relationship with stages I, II, III, V and VI of seminiferous epithelium cycle, and Leydig cell NA and numerical density (NV) were positively related to stage IV. However, only the correlation between NV and stage II was found in the aging group.
  
  
  CONCLUSIONS
  The stage number of seminiferous epithelium cycle was decreased in aging testes. Changes in the stage distribution in aging testes were related to the Leydig cell stereological parameters which presented as a sign of morphological changes.
authors.affiliation: Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Huang
authors.affiliation: Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, People's Republic of China. Electronic address: tzhuwj@jnu.edu.cn.
authors.forename: Wei-Jie
authors.initials: WJ
authors.lastname: Zhu
authors.affiliation: Department of Pathophysiology, Medical College, Jinan University, Guangzhou, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: National Research Institute for Family Planning, Beijing, People's Republic of China. Electronic address: yqgu90@126.com.
authors.forename: Yi-Qun
authors.initials: YQ
authors.lastname: Gu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D002452:Cell Count; D006801:Humans; D007985:Leydig Cells / Q000473:pathology*; D008297:Male; D012670:Seminiferous Epithelium / Q000473:pathology*; D013737:Testis / Q000473:pathology*
keywords: Aging men; Leydig cell; Pathological change; Seminiferous epithelium cycle; Stereological parameter