Vascular distribution of plasma catecholamines—pulmonary extraction, arterio-venous differences and effect of age

Abstract

In 19 normotensive patients undergoing cardiac catheterization, plasma samples were simultaneously collected from five different sites for measuring adrenaline and noradrenaline concentrations. Mean levels (±SEM) in pulmonary artery and aorta were 1.70±0.13 and 1.76±0.12 nmol/l for noradrenaline and 0.35±0.05 and 0.36±0.05 nmol/l for adrenaline, respectively. Thus, no pulmonary uptake of either catecholamine was demonstrated; this was independent of ventilatory lung function. Significant peripheral extraction was only found for adrenaline, and not for noradrenaline, so we found no evidence for the necessity of arterial blood sampling for noradrenaline determinations in this static study. Finally, a significant positive correlation of venous (r=0.56; p<0.01), but not arterial noradrenaline concentration with age was found, as was a negative correlation of both arterial (r=-0.55; p<0.01) and venous (r=-0.62; p<0.005) adrenaline concentrations with age. The release of adrenaline by the adrenal glands proved to be significantly decreasing with increasing age (r=-0.53; p<0.02).

Key words:

• adrenaline
• cardiac catheterization
• noradrenaline
• release of catecholamines
• uptake of catecholamines