The activity of some enzymes in the blood serum of warm-blooded and cold-blooded horses according to age

The research work was aimed at determining normal physiological values of the indicative enzyme activity (aspartate transaminase, AST EC 2.6.1.1, alanine transaminase, ALT EC 2.6.1.2, alkaline phosphatase, ALP EC 3.1.3.1, gamaglutamyltransferase, GGT EC 2.3.2.2 and lactate dehydrogenase, LD EC 1.1.1.27) in the blood serum of clinically healthy horses - warm-blooded and cold-blooded breeds. The enzymatic activity was determined by the photometric method utilizing diagnostic tests. The average values of the tested horses were as follows: AST 2.51 +/- 0.97, ALT 0.38 +/- 0.14, ALP 2.60 +/- 0.93, GGT 0.57 +/- 0.17, LD 4.23 +/- 1.53 mu kat.l(-1). The age dependence in the activity of AST and ALT showed the highest average values in the group of 7 and more years old horses (AST 3.38 +/- 0.90, ALT 0.50 +/- 0.17). Concerning the AST activity, the significant differences were discovered between these age groups: 1-3 years old and 7 and more years old horses (P < 0.001), 4 years old and 5-6 years old horses (P < 0.01), and 4 years old and 7 and more years old horses (P < 0.05). Concerning the ALT activity, these age groups showed statistically significant values: 1-3 years old and 7 and more years old horses, and also 4 years old and 7 and more years old horses (P < 0.01). Concerning the LD total activity related to the age, the statistically important differences were discovered between these age groups: 1-3 years old and 4 years old horses. The differences between the ALP and GGT enzymatic activity were not statistically significant. The AST activity dependence on the age was significant in the warm-blooded breed between these age groups: 1-3 years old and 5-6 years old horses (P < 0.05), 1-3 years old and 7 and more years old horses (P < 0.02), 4 years old and 5-6 years old horses (P < 0.02) and 4 years old and 7 and more years old horses (P < 0.01). Concerning the total ALT, ALP, GGT and LD enzymatic activity in the blood serum of the warm-blooded breed, no significant intra-breed differences were proved. Concerning the AST and ALT activity dependence on the age, significant differences between the age groups were discovered in the cold-blooded breed: 1-3 years old and 4 and more years old horses (P < 0.01).