Determinação das atividades séricas de creatina quinase, lactato desidrogenase e aspartato aminotransferase em eqüinos de diferentes categorias de atividade Determination of serum activities of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase in horses of different activities classes

<abstract language="eng">The creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) seric activities in horses of different activity classes (athlete, traction, and reproduction), were compared. Fifty-eight horses were alloted into three groups - group 1 with 20 athletes, "vaquejada" competitors; group 2 with 20 breeding horses; and group 3 with 18 draft horses, averaging 10 working hours daily. The average values for CK serum activity were 80.2, 83.9, and 94.4 U/l in groups 1, 2, and 3, respectively. Result of group 3 was significantly different from the other groups. The averages values for LDH were 102.5, 98.6, and 112.8 U/l in groups 1, 2, and 3, respectively, with no statistical difference between groups. The AST averages were 56.8, 33.0, and 50.1 U/l in groups 1, 2, and 3, respectively, with group 2 significantly differing from the others. Clinical biochemistry values of muscular function in horses varied according to activity category

Concentrações de creatino quinase, aspartato aminotransferase e desidrogenase lática em potros do nascimento até os seis meses de idade Concentration of creatine kinase, aspartate aminotransferase and lactate dehydrogenase in foals from birth up to sixth month

Dez potros da raça Puro Sangue de Corrida (PSC), de ambos os sexos, foram avaliados quanto à concentração das enzimas séricas creatino quinase (CK), aspartato aminotransferase (AST) e deshidrogenase lática (DHL). Foram colhidas amostras sangüíneas diariamente do 1º ao 7ºdia de vida e depois aos 15, 30, 60, 90, 120, 150 e 180 dias de idade. A concentração da CK mostrou um decréscimo significativo (p< 0,0003) do1º ao 7º dia de idade, e variação também significativa (p< 0,0044) entre o 15º dia de vida até os seis meses. A AST apresentou elevação significativa (p< 0,0001) até os 102 dias de idade, sofrendo posterior declínio até o 6º mês. A DHL apresentou decréscimo significativo (p< 0,0002) nas suas concentrações entre os 15 e 120 dias de idade, com posterior elevação até o 6º mês. Aos seis meses de idade as concentrações séricas de CK, AST e DHL, estão próximas as de eqüinos adultos.<br>Ten Thoroughbred foals, male and female, had the seric concentration of creatine kinase (CK), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) determined. Blood samples were collected every day from days 1 to 7 and on days 15, 30, 60, 90, 120, 150 and 180 of age. CK activity decreased significantly (p< 0.0003) in the first week and showed significant variation between day 15 and 6 months of age. AST showed a significant (p< 0.0001) increase in its values until 102 days of age, decreasing subsequently until 6 months of age. LDH values decreased significantly (p< 0.0002) between days 15 and 120, increasing subsequently until 6 months of age. At 6 months of age CK, AST and LDH activities were close to those of adult horses