RESUMO
OBJECTIVE: To compare proteomic profiles of seminal plasma from adolescents with varicocele and changes in semen quality with the plasma from adolescents with varicocele without seminal changes and from adolescents without varicocele. DESIGN: Observational study. SETTING: Patients in an academic research environment. PATIENT(S): Adolescents without varicocele (control group), adolescents with varicocele and normal semen quality (VNS group), adolescents with varicocele and abnormal semen quality (VAS group). INTERVENTION(S): Two semen collections at 1-week interval. Protein separation by two-dimensional protein electrophoresis, analysis by gel densitometry, and identification by mass spectrometry. MAIN OUTCOME MEASURE(S): Overexpressed proteins in each group, observed by increased densitometric signal in gels, and exclusively identified proteins in each group. RESULT(S): No differences were observed among the three groups regarding clinical parameters. In semen analysis, the VAS group presented lower sperm concentration, motility, and morphology compared with the VNS and control groups. Forty-seven protein spots of interest were submitted to mass spectrometry identification. Apoptosis regulation proteins were overexpressed in the VAS group, whereas spermatogenesis proteins were overexpressed in the VNS group. Controls presented proteins related to homeostasis. CONCLUSION(S): Changes in the proteomic profile of adolescents with varicocele and normal semen parameters (VNS group) indicate that normal semen analysis may not reflect alterations in proteins in seminal plasma. Implementation of proteomics will help characterize proteins identified in seminal plasma and will facilitate detection of new proteins associated with spermatogenesis and sperm function.
