Dopamine release from the porcine myocardium

Area of Science:

• Cardiology
• Neuroscience
• Biochemistry

Background:

• Dopamine, a catecholamine, influences cardiac function and is a precursor to noradrenaline in nerve terminals.
• Previous research has not investigated dopamine production within myocardial tissue.

Purpose of the Study:

• To determine if myocardial tissue produces and releases dopamine.
• To investigate the relationship between dopamine release and sympathetic noradrenergic activity in the heart.

Main Methods:

• Studied 13 young pigs with stable hemodynamic conditions and the heart in situ.
• Measured net release of dopamine into the coronary sinus.
• Analyzed dopamine release relative to noradrenaline levels.

Main Results:

• A significant net release of dopamine (1.39 +/- 0.36 ng/min X 100 g) from left ventricular muscle mass was observed (p < 0.01).
• Dopamine release occurred irrespective of the arteriovenous difference for noradrenaline.
• This indicates dopamine release from the heart is independent of sympathetic noradrenergic activity.

Conclusions:

• The myocardium produces and releases dopamine.
• This cardiac dopamine release is independent of sympathetic noradrenergic input.
• The regulatory mechanisms for myocardial dopamine release require further investigation.