troponin
Troponin is a highly specialized biochemical marker used primarily in clinical diagnostics. In a medical context, it is treated as a biomarker of cardiac injury; because it is released into the bloodstream when heart muscle cells are damaged, its presence is a definitive indicator of myocardial infarction (heart attack).
As a chemical substance and a protein complex, it is treated as an uncountable noun. It refers to the substance itself rather than individual molecules, meaning it does not typically take a plural form in professional medical reporting.
Meanings
A complex of three regulatory proteins that binds to tropomyosin and regulates the contraction of muscle fibers by controlling the interaction between actin and myosin.
The patient's troponin levels were significantly elevated, indicating myocardial infarction.