Osmotic sensitivity of canine spermatozoa

The objective of this study was to determine osmotic tolerance of canine spermatozoa. The study comprised three experiments: (1) spermatozoa suspended either in an egg yolk–citrate (EYC) extender or in Kenney skim milk extender were exposed to NaCl solutions ranging from 290 to 1500 mOsm; (2) spermatozoa suspended in EYC were exposed to 550 to 1500 mOsm solutions of glucose, galactose, or fructose; and (3) spermatozoa suspended in EYC or glucose-bovine serum albumin (G-BSA) were exposed to 0.6 M (∼900 mOsm) or 1.2 M (∼1600 mOsm) solutions of glycerol, ethylene glycol (EG), or dimethyl sulfoxide (Me 2SO). In all experiments, motility and membrane integrity of spermatozoa were assessed after they were diluted into isotonic medium at 37 °C. Exposure of canine spermatozoa to solutions of either NaCl or monosaccharides at osmolalities >500 mOsm caused a significant reduction of motility ( P