Alterations in muscular enzymes of horses competing long-distance endurance rides under tropical climate

Abstract

Estudaram-se as alterações de atividade das enzimas musculares creatino quinase (CK), lactato desidrogenase (LDH) e aspartato aminotransferase (AST) em um grupo de cavalos que utilizados em provas de enduro de 70 e 100km de distância, em cinco competições. Os valores (U/l) basais (antes da largada) foram 245,13±9,84 para CK, 496,61±14,76 para LDH e 328,95±8,65 para AST. Todas as atividades das enzimas decresceram no primeiro momento das provas (~30km). Valores de pico, significativamente diferentes, foram alcançados para CK (413,59±50,75) imediatamente após 70km de distância; 24 horas após para LDH (628,61±33,30); e 48 horas após as provas para AST (389,89±16,96). A monitoração do período de recuperação revelou diferente comportamento entre as concentrações enzimáticas com CK retornando aos valores basais 24 horas pós-provas (279,61 ± 23,05). LDH e AST retornaram aos valores basais, 72 horas pós-provas (505,25±33,78 e 359,35±24,90, respectivamente). Os dados obtidos revelaram diferentes alterações na concentração de enzimas musculares de cavalos de enduro, diretamente relacionadas com a duração do esforço. _________________________________________________________________________________________________________ ABSTRACT

This study tried to monitor the alterations of muscle enzymes activity - creatinokinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) - in a group of horses that participated of 70 and 100km distance rides in five competitions of an annual endurance championship under tropical climate. Pre ride levels (U/l) were 245.13±9.84 for CK, 496.61±14.76 for LDH, and 328.95±8.65 for AST. When compared to these levels, the results revealed a significant decrease in all enzymes activities in the first moment of the rides. Peak levels, significantly different, were reached, immediately after rides by CK (413.591±50.75); 24 hours post rides by LDH (628.61±33.30); and 48 hours after rides by AST (389.89±16.96). Monitoring of recovery period revealed different behavior among enzymes activities with CK values returning to pre ride values (279.61±23.05) 24 hours post rides, while LDH and AST values returned to pre ride values (505.25±33.78 and 359.35±24.90, respectively) 72 hours post rides. These data revealed different alterations in concentration of muscular enzymes in endurance horses directly related to the duration of the effort.