Hematochemical Patterns in Follicular Fluid and Blood Stream in Cycling Mares: A Comparative Note.
Authors: Satué Katiuska, Fazio Esterina, Ferlazzo Adriana, Medica Pietro
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Researchers examined biochemical differences between follicular fluid and blood plasma across the oestrous cycle in mares, measuring 31 analytes including metabolites, enzymes, electrolytes and proteins to understand how the follicular microenvironment changes as the dominant follicle develops. Blood contained significantly higher concentrations of glucose, bilirubin, urea nitrogen, iron and most proteins, whilst follicular fluid was notably enriched in lactate, cholesterol and triglycerides—suggesting active metabolic remodelling within the follicle itself. As follicles enlarged, glucose, cholesterol and triglycerides increased substantially, whilst enzyme activities (alkaline phosphatase, aspartate aminotransferase) and blood urea nitrogen decreased, indicating a shift towards an anabolic state supporting oocyte maturation and granulosa cell proliferation. These findings demonstrate bidirectional biochemical crosstalk between systemic circulation and the follicular compartment, implying that nutritional and metabolic status directly influences the oocyte's developmental microenvironment. For practitioners managing mares with subfertility, this work provides evidence that systemic metabolic and nutritional assessment may help predict or diagnose impaired follicular quality, offering potential routes to improve reproductive outcomes through targeted nutritional or metabolic intervention during the cycle.
Read the full abstract on PubMed
Practical Takeaways
- •Follicular fluid composition reflects metabolic changes in growing follicles and may provide biomarkers for assessing oocyte and follicular cell nutritional status in mares with reproductive problems
- •The distinct biochemical environment of large follicles suggests selective nutrient uptake and metabolic activity that could be exploited diagnostically to identify subfertile mares
- •Systemic blood parameters alone may not accurately reflect the intrafollicular microenvironment; direct follicular fluid analysis may improve diagnostic accuracy for mare infertility cases
Key Findings
- •Systemic blood concentrations of glucose, total bilirubin, BUN, iron, total proteins, and albumin were significantly higher than in follicular fluid (P < 0.05)
- •Lactate, cholesterol, and triglycerides were significantly higher in follicular fluid than in systemic blood (P < 0.05)
- •Large follicles showed elevated glucose, cholesterol, triglycerides, lactate, and bilirubin compared to medium and small follicles (P < 0.05)
- •Alkaline phosphatase, GGT, and AST enzymatic activities decreased progressively in medium and large follicles compared with small follicles (P < 0.05)