[The effect of storage time and temperature on the activity of glutathione peroxidase in plasma and whole blood of horses].

This research study investigates the impact of storage time and temperature on the activity of an enzyme called glutathione peroxidase (GSH-Px) in blood samples of horses. Additionally, the relationships between whole blood and plasma GSH-Px, as well as their correlation with certain blood components were also explored.

Approach and Findings

• The researchers conducted an experiment on blood samples from 93 horses to determine the effect of varied storage conditions on an enzyme, GSH-Px.
• They observed that at room temperatures (20-22 degrees C), the GSH-Px activity in plasma and whole blood samples stayed stable for at least three days. In contrast, the enzyme activity reduced significantly by 38% and 65% after 2 and 3 days respectively, if the whole blood samples were stored post dilution (lysate).
• The enzyme activity remained stable for three days in plasma, whole blood, and lysate samples stored at cooler temperatures such as 4 degrees C and -18 degrees C.
• For lysate samples kept frozen, the GSH-Px activity remained stable for up to 60 days. Meanwhile, the enzyme activity experienced fluctuations in plasma samples under the same conditions.

Exploring Relationships

• Apart from studying effects of storage on the enzyme, the researchers were also interested in the relationship between GSH-Px activities in plasma and whole blood.
• It was noted that the GSH-Px activity in plasma was 12.2 +/- 11.7 nkat/ml, whereas in whole blood it was 386 +/- 117 nkat/ml.
• The data showed a moderately weak correlation (r = 0.27, p < 0.01) between plasma and whole blood GSH-Px activity.
• Relationship between plasma and whole blood GSH-Px activity when correlated with the hematocrit and the hemoglobin content of the blood samples were slightly stronger, with coefficients of 0.38 and 0.35 respectively (p < 0.001).
• The coefficients for whole blood and whole blood related to hematocrit and hemoglobin content were 0.8 and 0.89 respectively (p < 0.001), indicating a strong correlation.

Study Implications

• The results of this study suggest that both storage time and temperature can significantly affect the enzyme activity in horse blood samples. This understanding is valuable for accurate enzyme assessment under different storage conditions.
• The correlations observed among GSH-Px activities and other blood components could also serve as a useful guide for better interpretation of laboratory results in future studies.