Gender differences in non-specific immune response to exercise in the lactate threshold: a study in equine athletes.

This research article investigates the gender differences in non-specific immune response to exercise in horses, focusing on polymorphonuclear neutrophils (PMNs), plasma glucose, and certain hormones. The study found males to have a higher PMN percentage, glucose levels, and other metrics compared to females, along with different correlations between variables.

Research Aim

• The research goal was to investigate the existence of any gender differences in the immune response of athletic horses, specifically the non-specific immune response. This is with a specific focus on a type of white blood cell, polymorphonuclear neutrophils (PMN), plasma glucose levels, and hormone levels.
• These responses were measured and assessed both before and after exercise at their lactate threshold (LT), the point at which lactate begins to accumulate in the blood.

Study Participants and Methods

• The researchers used a sample of 12 Anglo-Arabian horses, which included an even split between males and females of 4-7 years old.
• The horses underwent a submaximal exercise test measured at the lactate threshold.

Key Findings

• The results revealed that the male horses had a higher percentage of PMNs, greater plasma glucose values, better adherence index (AI), and a higher rate of random migration compared to the female horses.
• In female horses, there were significant negative correlations seen between the hormone cortisol, catecholamines (stress hormones), PMN levels and glucose with phagocytosis (the process by which cells engulf particles). Positive correlations were found between AI and catecholamines.
• Alternatively, the male horses showed negative correlations between random cell migration and chemotaxis (the movement of cells towards a chemical stimulus) with cortisol. However, there were positive correlations between cortisol and phagocytosis.

Conclusion

• Overall, this study suggests that there are distinct gender differences in the non-specific immune response of athletic horses to exercise, with differences in immune cell response, glucose levels, and hormone influences. This underlines the importance of considering gender in the understanding and potential application of these responses in exercise and health-based interventions for equine athletes.