Measurements of glycosaminoglycans in follicular, oviductal and uterine fluids of mares.

Eighteen fertile mares were used to determine the effects of the oestrous cycle and location in the reproductive tract on the amount and concentration of glycosaminoglycans in luminal fluids. Ovariohysterectomies were performed in 3 groups of 6 mares on Day 3 of behavioural oestrus, within 6 h after ovulation or on Day 8 of dioestrus. The lumina of the uterine horns and oviducts ipsilateral and contralateral to the active ovary were flushed and fluid was aspirated from the dominant follicle in the oestrous preovulation group. Glycosaminoglycans and protein concentrations were measured in these fluids. Both the total amount and the concentration of glycosaminoglycans were higher in the pre- and post ovulatory oestrous groups than in the dioestrous animals and they were higher in the luminal fluids than in oviductal fluids. There were no significant differences between the ipsilateral and contralateral sides of the reproductive tract and the concentration of glycosaminoglycans in follicular fluid was far greater than in other parts of the tract. The increased quantity and concentrations of glycosaminoglycans found in the tubular reproductive tract of mares during the follicular phase of the oestrous cycle supports the hypothesis that these molecules may play a role in events associated with fertilization.