Effect of racing on the serum concentrations of cardiac troponin I and creatine kinase myocardial band in racing camels (Camelus dromedarius)

This study was designed to investigate the effect of racing on the serum concentrations of cardiac troponin I (cTnI) and creatine kinase myocardial (CK-MB) in healthy racing camels (Camelus dromedarius). Twenty-three racing camels scheduled for a 5 km race were investigated in this study. From each camel, 3 blood samples were collected: 24 h before racing (T0), within 2 h after the race (T1) and 24 h post-race (T2). Following the 5 km race, 91.3 \% of the racing camels had increases in serum cTnI concentrations, while concentrations remained unchanged in 8.7 \%. The cTnI concentration (median 0.06 ng/mL; range, 0.03-0.15 ng/mL) was significantly higher (P < 0.001) than the pre-race values (median 0.04 ng/mL; range, 0.01-0.07 ng/mL). Twenty-four hours post-race, the cTnI concentrations had returned very nearly to their pre-race values (median 0.04 ng/mL; range, 0.00-0.09 ng/mL) and were not significantly different (P = 0.35) from the pre-race values. Following the 5 km race, increases in CK-MB mass were seen in 17.4 \% of the camels, with no changes in 4.3 \% and decreases in 78.3 \%. The CK-MB mass (median 0.41 ng/mL; range, 0.19-0.60 ng/mL) did not differ significantly (P = 0.84) when compared to the pre-race values (median 0.42 ng/mL; range, 0.32-0.55 ng/mL). Twenty-four hours post-race, the CK-MB mass concentrations (median 0.41 ng/mL; range, 0.15-0.55 ng/mL) did not differ significantly (P > 0.05) compared to pre-race or immediate post-race values. Resting cTnI concentrations in the racing camels were initially low, but increased above the baseline level in most of the camels immediately after racing, and returned to pre-race values within the 24-h post-race period. CK-MB is a less sensitive biomarker for myocardial activity as compared with cTnI. These findings could be of importance when evaluating racing camels with suspected cardiac disease after recent hard exercise.