The development of highly sensitive assays for cardiac troponin T (hs-cTnT) and cardiac troponin I (hscTnI) represents the latest technological advance in a field that has witnessed continual progression toward more sensitive and more precise tools for detecting cardiac injury. The hs-cTnT assay, for example, can detect cTnT concentrations 10-fold lower than the current fourth-generation assay,...

During β-adrenergic stimulation, cardiac troponin I (cTnI) is phosphorylated by protein kinase A (PKA) at sites S23/S24, located at the N-terminus of cTnI. This phosphorylation has been shown to decrease KCa and pCa50, and weaken the cTnC-cTnI (C-I) interaction. We recently reported that phosphorylation results in an increase in the rate of early, slow phase of relaxation (kREL,slow) and a decr...

Cardiac troponin T (cTnT) and troponin I (cTnI) are cardiac regulatory proteins that control the calcium mediated interaction between actin and myosin [1]. The troponin complex consists of three subunits: troponin C, troponin I, and troponin T. This complex is located on the myofibrillar thin (actin) filament of striated (skeletal and cardiac) muscle. The cardiac isoforms troponin T and I are o...

Troponin I is a subunit of the thin filament-associated troponin-tropomyosin complex involved in calcium regulation of skeletal and cardiac muscle contraction. We deleted the cardiac isoform of troponin I by using gene targeting in murine embryonic stem cells to determine the developmental and physiological effects of the absence of this regulatory protein. Mice lacking cardiac troponin I were ...

Nuclear factor of activated T cell (NFAT) is a ubiquitous regulator involved in multiple biological processes. Here, we demonstrate that NFAT is temporally required in the developing atrial myocardium between embryonic day 14 and P0 (birth). Inhibition of NFAT activity by conditional expression of dominant-negative NFAT causes thinning of the atrial myocardium. The thin myocardium exhibits seve...

Troponin I is the actomyosin ATPase inhibitory subunit present in the thin filament regulatory complex. The complete amino acid sequence of crayfish tail muscle troponin I has been determined. The protein is composed of 201 amino acid residues and has a molecular weight of 23,547. The N terminus is blocked, likely by an acetyl group. Crayfish troponin I shows a rather low (20-25%) sequence iden...

We have developed an in vitro motility assay to make a detailed quantitative analysis of Ca2+ control of skeletal-muscle troponin-tropomyosin control of actin-filament movement over immobilized myosin. Ca2+ regulates both filament velocity and the fraction of filaments that are motile. We have demonstrated that the two effects are due to separate interactions of troponin C with troponin I and t...

carbon monoxide (co) poisoning, though with different sources, is one of the most deadly emergencies in all countries. co can threaten men's life by several paths especially cardiac complications, which can mimic other cardiac problems such as myocardial infarction. the objective of this study was to determine ecg findings and serum troponin i levels in co poisoned patients. in this analytical ...

BACKGROUND Troponin I is the gold standard for the diagnosis of adult acute coronary syndrome. Although it is known that a hypoxic fetus may produce cTnI, fetal cTnI passage in maternal blood has never been documented. CASE REPORT We report a case where the rise of cTnI in the blood of a pregnant woman was not related to maternal heart disease. Instead, it might be suggestive of a fetal cardiac...

Background: The cardioprotective effect of ischemic preconditioning has been known for many years. Since the temporary ischemia in the heart may cause lethal cardiac effects, the idea of creating ischemia in organs far from the heart such as limbs was raised as remote ischemic preconditioning (RIPC). We hypothesized that the extension of RIPC has more cardioprotective effect in patients undergo...