[Troponins: biological and clinical aspects].
The troponin complex is composed of three subunits called troponin I, troponin T and troponin C. Heart isoforms of troponin I and T are not expressed in skeletal muscle. They can be assayed in blood samples by immunoassays in order to diagnose and monitor patients with heart diseases. Troponins released in the blood after necrosis are mainly found as binary or ternary complexes. The kinetics of their release are close to that of creatine-kinase MB, but the return to normal is observed after longer periods of time. The excellent analytical sensibility of troponin assays allows the detection of minor heart damages. Because of its high specificity, the heart isoform of troponin I is use to diagnose heart damages in the presence of damages to other organs such as muscle and kidney. The resynthesis of troponin T by the skeletal muscle decreases its interest to diagnose muscle-associated heart diseases. In spite of the present lack of standardisation of troponin I assays, its detection associated to an other early myocardial marker, such as myoglobin, allows a rapid and reliable diagnostic of myocardial infarction. The study of post-translationally modified forms of troponins and their assays could permit a diagnosis and a more precise follow-up of patients with cardiac necrosis.
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Service de biochimie, Hôpital Tenon, 4, rue de la Chine, 75970 Paris cedex 20, France.
D000595:Amino Acid Sequence; D015415:Biomarkers / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood; D006331:Heart Diseases / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007527:Isoenzymes; D008969:Molecular Sequence Data; D014336:Troponin / Q000097:blood*; D019210:Troponin I / Q000737:chemistry
D015415:Biomarkers; D007527:Isoenzymes; D014336:Troponin; D019210:Troponin I; D003402:Creatine Kinase