title: [Changes in morphology and steroidogenic function of aged human Leydig cells].
abstract: OBJECTIVE
  To investigate the changes of morphology and steroidogenic function in aged human Leydig cells and to understand the mechanism of late onset hypogonadism (LOH).
  
  
  METHODS
  Ten young and ten aged male subjects were enrolled in this study. AMS (Aging Male's Symptoms) scale was used for symptom evaluation. Testes species with LOH were utilized as the research model. Then the histological changes in testis and ultrastructure of Leydig cells were observed by HE staining and electron microscopy (EM), respectively. The serum total testosterone concentrations were measured by an ELISA kit. The expressions of steroidogenic acute regulatory (StAR) protein and cholesterol-side-chain cleavage enzyme (P450scc) were detected by western blot.
  
  
  RESULTS
  The scores of AMS in the aged group were higher than those in the young group with decreased serum testosterone levels (61.25 ± 7.08 vs. 20.75 ± 3.73,P<0.001). And the serum testosterone level of the aged human was lower than that of the young human [(3.12 ± 0.58) μg/L vs. (6.29 ± 1.17) μg/L,P<0.05]. HE staining showed that degenerative changes occurred in the aged human testes. And many swollen mitochondria with mitochondrial cristae that disappeared were found in Leydig cells of the aged human by EM. The serum total testosterone level of the aged human was significantly lower than that of the young group. And the expressions of StAR and P450scc protein in the aged group were significantly lower than those of the young group.
  
  
  CONCLUSIONS
  Mitochondrial swelling and decreased expressions of StAR and P450scc were closely related to the reduced ability of testosterone synthesis in aged males. And the exact mechanism needs further investigation.
authors.affiliation: Andrology Center,Peking University First Hospital, Beijing 100034, China.
authors.forename: Wei-ren
authors.initials: WR
authors.lastname: Li
authors.forename: Bo-xuan
authors.initials: BX
authors.lastname: Han
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Guang-yong
authors.initials: GY
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Yan-qing
authors.initials: YQ
authors.lastname: Gong
authors.forename: Zhe-zhu
authors.initials: ZZ
authors.lastname: Gao
authors.forename: Wan-shou
authors.initials: WS
authors.lastname: Cui
authors.forename: Guang-yi
authors.initials: GY
authors.lastname: Bai
authors.forename: Zhong cheng
authors.initials: Zc
authors.lastname: Xin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007006:Hypogonadism / Q000378:metabolism / Q000473:pathology; D007985:Leydig Cells / Q000502:physiology / Q000648:ultrastructure*; D008297:Male; D008933:Mitochondrial Swelling; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D013737:Testis / Q000473:pathology; D013739:Testosterone / Q000097:blood*; D055815:Young Adult; D000098682:Steroidogenic Acute Regulatory Protein
chemical_list: D010750:Phosphoproteins; D000098682:Steroidogenic Acute Regulatory Protein; D013739:Testosterone; D002786:Cholesterol Side-Chain Cleavage Enzyme