Twelve steers were intraruminally administered a high dose (0.5g/kg BW) of urea to study the damage effect of ammonia poisoning on liver and/or muscles. Blood samples were collected to determine ammonia and activities of γGT, AST and CK. Eleven steers were successfully poisoned and treated properly, but one succumbed. Poisoned cattle showed high concentration of ammonia, and higher activities of AST and CK. The higher the ammonia, the greater were the activities of AST (r=0.59) and CK (r=0.61). The correlation between AST and CK was high and significant (r=0.80), but not between AST and γGT (r=0.19). The activities of AST and CK were higher after the beginning of the convulsive episodes due to ammonia poisoning. Those results showed that occurred muscle damage instead of liver damage since CK is a typical enzyme from skeletal muscle; AST is found either in skeletal muscle and hepatocytes, while γGT is present in hepatic cells.Keywords: cattle, ammonia poisoning, urea, muscle damage, liver AST (r=0,59) Palavras-chave: bovino, intoxicação por amônia, uréia, lesão muscular, fígado
RESUMO
Doze novilhos foram experimentalmente intoxicados por administração intrarruminal com alta dose de uréia (0,5g/kg PV) para estudar o efeito da intoxicação por uréia sobre o fígado e/ou musculatura. Foram coletadas amostras de sangue no decorrer do experimento para determinar o teor de amônia e as atividades de gama glutamiltransferase (γGT), aspartato aminotransferase (AST) e creatina quinase (CK). Onze novilhos apresentaram quadro clínico típico de intoxicação por amônia, porém um animal sucumbiu. Animais intoxicados apresentaram alto teor de amônia e elevada atividade de CK e AST. Quanto mais elevados foram os teores de amônia maiores foram as atividades de