Acid-base balance parameters of follicular fluid and venous blood in cattle

Abstract

The study aimed to compare differences of physiological acid-base balance (ABB) parameters in follicular fluid (FF) and venous blood (VB) and to evaluate ABB parameters in FF collected from different ovarian follicles in dairy cows and heifers. The ABB parameters (pH, pCO2, pO2, HCO3– and base excess (BE)) in the FF of the preovulatory follicle, of the dominant follicle on the 9th day of the cycle and of the superovulatory estrous follicles were compared to VB. Similarly, the dynamics of the ABB profile in FF and VB were monitored in repeated sampling in a group of heifers stimulated by follicle-stimulating hormone (FSH). Higher values of pH and pO2 and lower values of pCO2, HCO3– and BE were found in FF compared to VB in all experiments. Laterality of ovaries, time of sampling, ovarian activity or stimulation of the follicular development by FSH did not significantly influence ABB parameters. We found higher pH (7.392 ± 0.027 vs. 7.364 ± 0.032) and pO2 (13.83 ± 2.20 kPa vs. 4.50 ± 0.67 kPa), lower pCO2 (5.70 ± 0.39 kPa vs. 6.54 ± 0.61 kPa), HCO3– (25.51 ± 1.52 mmol/l vs. 26.86 ± 2.12 mmol/l) and BE (1.14 ± 1.57 mmol/l vs. 1.95 ± 2.2 mmol/l) in FF compared to VB in all non-stimulated cows. Similar relationships between FF and VB were found in all FSH stimulated cows. The study provides as yet unknown knowledge on the physiology of follicular fluid in cattle.

Electrolytes, Metabolic And Acid-Base Parameters In Blood And Fluids of The Reproductive Tract During In Vivo Maturation of Bovine Oocytes

“…Similar to electrolytes and total proteins, acid-base parameters and gases in bovine FF and blood have also been reported by many studies in samples of different days of the estrous cycle or in follicles of different developmental stages 12,22,23,[33][34][35] . However, no report to date has specifically characterized blood and FF parameters while oocytes undergo maturation.…”

“…Here we found that during this unique window, blood parameters were well-maintained, yet FF underwent significant changes include pH, pCO2, and TCO2. Although Indrova et al 12 collected FF at different times post PG or superovulation, these were conducted in three different experiments, and no comparisons could be made. Additionally, many studies used OPU for FF collection, which increased pO2 due to the mixing of FF with air in the OPU tubing 34,36,37 .…”

“…Numerous prior studies have reported electrolytes, metabolic and acid-base parameters in bovine blood and follicular and a few on oviductal, and uterine fluids 8,9,12 . However, the vast majority of them used slaughterhouse materials .…”

“…The oviduct and uterine environments, also play vital roles in sperm transportation, reservoir, and oocyte fertilization 11 . The fluids of the follicle (FF), oviduct (OF), and uterus (UF) are constituted from a combination of selective serum transudate and locally produced molecules, secreted from the uterine, oviduct epithelial, and granulosa cells 8,12 .…”

Reproductive Consequences of Electrolyte Disturbances in Domestic Animals

“…However, the literature does not describe the collection of follicular fluid to assess the acid-base balance from live animals. Maintaining the acid-base balance in body fluids is essential for maintaining whole-body homeostasis, and many deviations indicate disorders [ 113 ]. Female fertility disorders are correlated with electrolyte concentration [ 66 ].…”