Cytochemistry of peripheral blood leukocytes in thoroughbred foals.

The research here details the findings of a study aimed at understanding the staining capabilities of leukocytes and identifying the proportions of blood lymphocytes that test positive for certain enzymes in the peripheral blood of thoroughbred foals of different ages.

Study Methodology and Sample Population

• The study took into consideration blood samples from 60 healthy thoroughbred foals which were one day, three days, and one year old, equally split between males and females.
• The blood samples were collected from the jugular veins of these foals.

Testing for Enzymes and Staining Patterns

• The researchers studied the cytochemical staining patterns of the leukocytes. They primarily tested for the presence of the enzymes alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACPase).
• They detected Peroxidase (PO) activity in neutrophils, eosinophils, and monocytes. Lymphocytes were found to be negative for PO staining.
• Through Periodic acid-Schiff (PAS) staining, they observed reactivity in neutrophils and monocytes, but not in eosinophils.

Surface Enzyme Analysis

• Monocytes were found to be strongly positive for both ANAE and ACPase, and many lymphocytes also exhibited these enzymatic reactions.
• Neutrophils exhibited weak positive reactivity for both ANAE and ACPase.
• Eosinophil granules were generally negative or only weakly positive for ANAE, and typically negative for ACPase.

Analysis of ANAE and ACPase in Lymphocytes Over Time

• ANAE positive peripheral blood lymphocytes (PBL) showed a decreasing trend in percentages as the foals aged, while ACPase positive PBL showed an increasing trend.
• There was not a significant difference in enzyme levels between male and female foals, but age had a significant effect on both ANAE and ACPase positivity.

Conclusion

• The study thus contributes hematological data that can serve to assist in the identification of blood cells in thoroughbred foals.
• The differences in cytochemical staining patterns observed across different types of leukocytes and the variations in enzyme positivity over time hint at the potential for age and specific blood cell types to influence these aspects of blood chemistry in thoroughbred foals.