METHOD OF EUTHANASIA DOES NOT AFFECT SPERM MOTILITY IN THE LABORATORYRAT

To determine if anesthetic agents used in laboratory animal euthanasia affected sperm motion parameters, rats (n = 10 per group) were euthan ized by one or 5 different methods: decapitation alone, or decapitatio n following either ether, halothane, or Nembutal anesthesia, or CO2 as phyxiation. Sperm were collected from the distal cauda epididymis, dil uted, and videotaped for computer-aided sperm analysis (CASA; HTM-2030 , Hamilton-Thorn Research, Beverly, MA). The percentage of motile sper m (MOT), their straight-line velocity (VSL), average path velocity (VA P), curvilinear velocity (VCL), linear index (LINX), and linearity (LI N) were measured on greater-than-or-equal-to 200 motile sperm per samp le. No significant differences in any of these 6 motion parameters wer e found among the treatment groups. Thus, none of these 5 methods of e uthanasia affect sperm motion as assessed by CASA methods, making them equally suitable for use in reproductive toxicology studies.