Detection of chemotactic factors in preovulatory follicular fluid from mares.

This research investigates the presence of chemotactic factors, which influence cell movement, in the fluid of preovulatory follicles in mares, aiming to understand their role in ovulation which resembles an inflammatory process. The study uses different treatments and measures the movement of neutrophils, a type of white blood cell, over time after a follicle reaches a certain size and is treated with human chorionic gonadotropin.

Objective and Methodology

• The study’s main objective was to detect and assess the chemotactic activity in the follicular fluid of estrous mares during ovulation. Particularly, they focused on the time periods of 0, 12, 24, and 36 hours after the detection of a 35-mm follicle treated with human chorionic gonadotropin.
• To evaluate the chemotactic activity, they observed the directional movement of equine neutrophils in the presence of follicular fluid, employing agarose—a polymer used in biology for its gel-forming properties—as the migration medium.

Findings

• The researchers found that follicular fluid does indeed function as a chemoattractant for neutrophils, directing their movement. This suggests that the fluid contains factors that stimulate and attract inflammation-related cells as part of the ovulation process.
• However, there was no significant difference detected in the level of chemotactic activity at the different time intervals after the follicle had been treated with human chorionic gonadotropin. This implies that the concentration or activity of the chemotactic factors in the follicular fluid is consistent throughout the ovulation process.
• The researchers also found the chemotactic properties of the follicular fluid and serum—a component of blood—to be similar, indicating that these elements may share common characteristics or substances involved in chemotaxis.

Effects of Different Treatments on Follicular Fluid

• The study also tested the effect of different treatments such as heat, trypsinization, charcoal treatment, and dialysis on the chemotactic activity of the follicular fluid and serum.
• Applications of heat and trypsinization significantly reduced the chemotactic activity, suggesting that the chemotactic factors may be sensitive to these treatments or could be proteins that are altered or denatured by them.
• The charcoal treatment virtually removed the chemotactic activity. This treatment is commonly used to bind and remove organic compounds, implying that the chemotactic factors in the follicular fluid might be of organic nature.
• Dialysis significantly reduced the chemotactic activity of the follicular fluid and serum as well. As dialysis can remove small molecules, the chemotactic factors might be of relatively large molecular weight.

Conclusion and Future Research

• The researchers concluded that while chemotactic factors appear to be present in follicular fluid, more research is needed to establish the role and importance of these factors in ovulation in mares.