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 dehydr ogenase, LD EC 1.1.1.27) in the blood serum of clinically healthy hors es - warm-blooded and cold-blooded breeds. The enzymatic activity was determined by the photometric method utilizing diagnostic tests. The a verage 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 s howed 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 acti vity, the significant differences were discovered between these age gr oups: 1-3 years old and 7 and more years old horses (P < 0.001), 4 yea rs 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 a ge 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 difference s between the ALP and GGT enzymatic activity were not statistically si gnificant. The AST activity dependence on the age was significant in t he 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 ho rses (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 th e warm-blooded breed, no significant intra-breed differences were prov ed. Concerning the AST and ALT activity dependence on the age, signifi cant differences between the age groups were discovered in the cold-bl ooded breed: 1-3 years old and 4 and more years old horses (P < 0.01).