Serum cardiac troponin T as a biomarker for acute myocardial injury induced by low doses of isoproterenol in rats
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In rats, high doses of isoproterenol (Iso) have caused acute myocardial lesions and increased serum levels of cardiac troponin T (cTnT). We determined whether low doses of lso also cause cardiac alterations and whether monitoring cTnT levels could detect this injury. Rats received 8 to 500 μg/kg lso and were followed for 3 to 48 h. Lesion severity was scored from 0 to 5. Within 3 h, mean cTnT was elevated in all 29 rats receiving 8, 16, 32, or 64 μg/kg lso (0.20 to 0.28 ng/mL), but minimal lesions occurred in only two animals. However, by 6 h, cardiac lesions and increases in serum cTnT (mean=0.21 to 0.23 ng/mL) were observed in all 14 rats receiving 32 or 64 μg/kg lso. Doses of 125, 250, or 500 μg/kg lso caused more significant increases in cTnT levels and marked myocardial lesions that reached a peak 3 to 6 h after dosing. The magnitude of the lesions and cTnT levels declined between 12 and 48 h post treatment. Thus, a range of low lso doses can cause myocardial lesions, and serum cTnT levels can be monitored to detect the onset and progression of this type of acute cardiac injury in rats; however, careful attention to dosing and sampling times is critical to interpretation.
Index EntriesCardiac troponin T isoproterenol myocardial damage low dose
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- 1.Chappel, C. I., Rona, G., Balazs, T., et al. (1959). Severe myocardial necrosis produced by isoproterenol, in the rat. Arch., Int. Pharmacodyn. Ther. 122:123–128.Google Scholar
- 2.Rona, G., Chappel, C. I., Balazs, T., et al. (1959). An infarct-like myocardial lesion and other toxic manifestations produced by isoproterenol in the rat. Arch. Pathol. 67: 448–453.Google Scholar
- 4.Davies, M. J. (1977). The pathology of mycardial ischaemia. J. Clin. Pathol. Suppl. (R. Coll. Pathol.) 11:45–52.Google Scholar
- 8.O'Brien, P. J., Daweron, G. W., Beck, M. L., et al. (1997). Troponin T is a sensitive, specific biomarker of cardiac injury in laboratory animals. Lab. Animal Sci. 147:486–495.Google Scholar
- 14.Bertinchant, J. P., Robert, E., Polge, A., et al. (2000). Comparison of the diagnostic value of cardiac troponin I and T determinations for detecting early myocardial damage and the relationship with histological findings after isoproterenol-induced cardiac injury. Clin. Chimica Acta 298: 13–28.CrossRefGoogle Scholar
- 15.Bartsch, V. W., Roesch, E., Hebold, G., et al. (1974). Einbeitrag zur differenzi erang zwischein echter und scheinbarer, β-rezeptoren blockade am herzen. Arzneim-Forsch (Drug Res.) 24:303–308.Google Scholar
- 16.Mueller-Bardorf, M., Hallermayer, K., Schroder, A., et al. (1997). Improved troponin T ELISA specific for cardiac troponin T isoform: assay development and analytical and clinical validation. Clin. Chem. 43:458–466.Google Scholar