title: Reduced number of circulating endothelial progenitor cells in hypogonadal men.
abstract: BACKGROUND
  Endothelial dysfunction seems to be the first step of the atherosclerotic process. In the past few years, it has been demonstrated that injured endothelial monolayer is restored by a premature pool of circulating progenitor cells (PCs) and a more mature one of circulating endothelial PCs (EPCs). Even though there is increasing evidence that estrogens play a beneficial role on EPCs and, even if debated, on the cardiovascular system, less is known about androgens.
  
  
  OBJECTIVE
  Our objective was to evaluate the levels of circulating PCs and EPCs in men with hypogonadotropic hypogonadism (HH) and the effect of prolonged testosterone (T) replacement therapy on these cells.
  
  
  METHODS
  We conducted a prospective study on males with HH at a university andrological center.
  
  
  METHODS
  The study included 10 young HH patients (28.6 +/- 3.1 yr) and 25 age-matched controls.
  
  
  METHODS
  Idiopathic HH patients were treated with T gel therapy, 50 mg/d for 6 months.
  
  
  METHODS
  We assessed circulating PC and EPC concentrations and immunocytochemistry for androgen receptor expression on cultured EPCs.
  
  
  RESULTS
  At baseline, HH patients showed a significant reduction of both PCs and EPCs with respect to controls. T replacement therapy induced a significant increase of these cells with respect to baseline. Immunocytochemistry on cultured EPCs showed strong expression of the androgen receptor.
  
  
  CONCLUSIONS
  Hypotestosteronemia is associated with a low number of circulating PCs and EPCs in young HH subjects. T treatment is able to induce an increase in these cells through a possible direct effect on the bone marrow.
authors.affiliation: Department of Histology, Microbiology, and Medical Biotechnologies, Centre for Male Gamete Cryopreservation, University of Padova, Padova, Italy. carlo.foresta@unipd.it
authors.forename: C
authors.initials: C
authors.lastname: Foresta
authors.forename: N
authors.initials: N
authors.lastname: Caretta
authors.forename: A
authors.initials: A
authors.lastname: Lana
authors.forename: L
authors.initials: L
authors.lastname: De Toni
authors.forename: A
authors.initials: A
authors.lastname: Biagioli
authors.forename: A
authors.initials: A
authors.lastname: Ferlin
authors.forename: A
authors.initials: A
authors.lastname: Garolla
mesh_terms: D000328:Adult; D001772:Blood Cell Count; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D005640:Follicle Stimulating Hormone / Q000097:blood; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D006801:Humans; D007006:Hypogonadism / Q000097:blood* / Q000188:drug therapy; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D010919:Placebos; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects; D013739:Testosterone / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use
chemical_list: D010919:Placebos; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone