Question

During his annual check-up, his doctor looked alarmed when his blood test revealed elevated cardiac troponin levels.

Describe the function of troponin in healthy cardiomyocytes.

Explain why Travis’ doctor was alarmed at his blood test results. Why did his serum cardiac troponin levels increase?

Answer 1

Troponins are proteins that regulate the muscular contraction of the cardiac muscles. It is a complex of three proteins troponin C, troponin I, and troponin T and is located between actin filaments of the muscles.

The troponin I inhibits the actomyosin interaction. In the presence of calcium when troponin C binds to calcium then it induces a conformational change in the Troponin I leading to binding of the Troponin T to the actin along with the tropomyosin and thus leading  to cross-bridge cycling and contraction to produce systole in the heart muscle.

troponin in general is not detected at its normal level in the blood. The increased troponin level in the blood might indicate a heart injury where the blood supply to heart muscles become blocked. The troponin is released into the blood as a result of this injury like a heart attack, which makes the doctor alarmed as it indicates a malfunctioning and weakening of the heart.