An evaluation of hamster, rat, and mouse sperm-cell motility in media formulated with water of different qualities.

The in vitro motility of caudal epididymal spermatozoa from four hamsters, four rats, and four mice was compared in modified Tyrode's medium (TLP-PVA) prepared with water of three qualities: (1) Sigma tissue culture water, 18 m omega, high quality (HQ); (2) deionized distilled water, 4.5 m omega prior to distillation, intermediate quality (IQ); and (3) tap water, low quality (LQ). The objective was to evaluate the in vitro bioassay potential of spermatozoa from these species, in terms of relative sensitivities to toxins in different qualities of water. An average sperm motility index (SMI) was calculated per treatment at 2, 4, and 6 hr, where SMI = fpm2 x % motility. Hamster SMI could be used to discriminate between HQ and IQ media at 4 and 6 hr (P less than 0.001), while rat SMI could be used to discriminate between HQ and IQ media at 6 hr (P less than 0.05). Mouse SMI did not differ between HQ and IQ media. The ability to discriminate between extremes in quality. HQ or IQ vs LQ, was equal between species (P less than 0.001). These results suggest that hamster spermatozoa provide the more sensitive in vitro bioassay model, while rat and mouse spermatozoa may be used for assay of extremes in water quality.