DIFFERENTIAL REACTIVITY OF CARDIAC AND SKELETAL-MUSCLE FROM VARIOUS SPECIES IN 2 GENERATIONS OF CARDIAC TROPONIN-T IMMUNOASSAYS

Cardiac troponin T (cTnT) is being increasingly used as a blood marker of acute or ongoing cardiac injury in various laboratory animals alth ough the range of species in which it is applicable and its tissue sel ectivity has not been demonstrated. To address this concern, cardiac a nd skeletal muscle biopsy specimens from various species were homogeni sed and diluted, and their reactivity was then determined in the first - and second-generation immunoassays for cTnT. Cardiac tissue reactivi ty was found for all species studies, being highest for rats and sever al-fold lower for chickens and fish, and intermediate for dogs, pigs, goals, cows, sheep, horses, rabbits, and turkeys. Skeletal muscle had 10 per cent of the reactivity of cardiac muscle in the first-generatio n assay and 1 per cent of the reactivity of cardiac muscle in the seco nd-generation assay. In the absence of moderate to marked skeletal mus cle injury, the second-generation cTnT immunoassay has sufficient reac tivity and tissue-selectivity to serve as a blood test for the discrim ination between cardiac and skeletal muscle injury in a wide range of species.