Induction of dog sperm capacitation by glycosaminoglycans and glycosaminoglycan amounts of oviductal and uterine fluids in bitches

Ejaculated sperm collected from 12 beagle dogs were incubated in canine cap acitation medium (CCM), supplemented with 5 mu g/ml chondroitin sulfate A ( CS), 5 mu g/ml hyaluronic acid (HA), or 5 mu g/ml heparin (HP) for 7 hr at 38 degrees C in a 5% CO2 in air atmosphere to investigate the effects of gl ycosaminoglycans (GAGs) on dog sperm capacitation. The percentages of motil e sperm, hyperactivated sperm (%HY), and acrosome-reacted sperm (%AR) in al l media were examined after 4 hr and 7 hr of incubation. The oviducts and u teri of 9 anestrous and 18 estrous beagle bitches were removed under haloth ane inhalation anesthesia to measure the total GAG amounts in oviductal and uterine fluids. The lumens of the ampulla of the oviducts, isthmus of the oviducts, and the uterine horns were each flushed with 1 ml HEPES-EDTA flui d. Total GAG amounts in the flush fluids obtained were measured with a spec trophotometer. Sperm motility (51-59%), %HY (79-86%), and %AR (31-36%) in C CM supplemented with CS, HA, or HP were significantly higher after 7 hr of incubation than when incubated in CCM without GAGs (P<0.01 or 0.05). The me an total GAG amounts in the fluids from the ampulla and isthmus of the ovid ucts and the uterine horns in the estrous bitches were higher than in the a nestrous bitches. These results indicate that GAGs in the oviductal and ute rine fluids in estrous bitches are associated with in vivo sperm capacitati on.