[LDH and CK isoenzyme patterns in the blood plasma of horses with elevated CK, LDH and AST activities].

This research article uses a study to compare the abundance of specific blood plasma enzymes in two groups of horses, and suggests that an imbalance in these enzymes may signify muscle membrane leakage.

Objective and Methodology

• The study aimed to identify and compare the distribution of Lactate Dehydrogenase (LDH) and Creatine Kinase (CK) isoenzymes in the blood plasma among groups of Thoroughbred horses with different health statuses.
• The first group (reference group) consisted of ten clinically sound Thoroughbreds with no elevated clinico-chemical blood variables. The second group (trial group) involved 57 Thoroughbreds with histories of mild locomotor (movement) disturbances, poor performance, and elevated CK, LDH and/or Aspartate Aminotransferase (AST) activities.
• The trial group was further subdivided based on the number and extent of altered blood variables.

Results

• In the reference group, the LDH and CK isoenzyme distribution in the blood plasma was: 22% LDH1, 36% LDH2, 34% LDH3, 6% LDH4, 2% LDH5 and 75% CK1 with 15% CK2.
• All trial groups exhibited a similar pattern of changes in their isoenzyme distribution irrespective of the type and combination of altered enzyme activities.
• There was a significant increase in the shares of CK1, LDH4 and LDH5 enzymes, while the shares of CK2, LDH1 and LDH2 decreased.
• A multiple analysis of variance showed that only increased total CK activities had a significant effect on the distribution of LDH and CK isoenzyme patterns in the trial group.

Conclusion

• The study suggests that the imbalanced distribution pattern of LDH and CK isoenzymes in the trial group indicated an increase in skeletal muscle membrane leakage.
• This research could be significant in understanding and diagnosing muscle-related disorders in horses, particularly Thoroughbreds, who are routinely pushed to extreme physical limits in racing and other performance disciplines.