SRF2015 POSTER PRESENTATIONS (1) (56 abstracts)
1University of Nottingham, Loughborough, UK; 2Guide Dogs for the Blind Association, Bishops Tachbrook, UK; 3The James Hutton Institute, Aberdeen, UK.
Introduction: A temporal decline in canine male fertility parallels that reported in the human. Our hypothesis is that this is associated with exposure to environmental chemicals (ECs). We investigated i) a relationship between canine testicular chemical profiles and Sertoli cell numbers and ii) the effects of testicular concentrations of chemicals on sperm DNA fragmentation, motility and vitality.
Methods: Canine adult testes (routine castrations) from the West Midlands (WM: n=26), East Midlands (EM two regions: n=5, n=7) and SE England (SE: n=15) were analysed for seven PCB congeners, seven PBDE congeners and DEHP. Sertoli cell numbers, identified by vimentin immunohistochemistry, were counted and adjusted for tubular area (n=5/region). Canine sperm samples (n=10), were cultured with PCB153 and DEHP (0, 2×, 10×, 100× mean testicular levels). Vitality, motility and sperm DNA fragmentation were analysed at 0, 120 and 240 min.
Results: Mean testicular levels for PCB 153 and DEHP were 0.063 ± 0.010 μg/kg (n=35) and 0.182 ± 0.044 μg/g (n=26) respectively. Higher levels of PCB and PBDE were found in WM testes (n=12) (?PCB: P<0.05, ?PBDE: P<0.01) than in other regions (EM: n=9, SE: n=14). WM testes also had the lowest Sertoli cell numbers (P<0.05). MTL of PCB153 or DEHP individually increased sperm DNA fragmentation (P=0.055) and reduced sperm vitality and motility (P<0.001).
Conclusion: Regional differences in testicular ECs, their association with reduced Sertoli cell numbers and their ability to directly affect sperm quality suggests that declining canine fertility has an environmental aetiology.