M. Johansson et al., CARDIORENAL EPINEPHRINE KINETICS - EVIDENCE FOR NEURONAL RELEASE IN THE HUMAN HEART, American journal of physiology. Heart and circulatory physiology, 42(5), 1997, pp. 2178-2185
There are experimental data suggesting that epinephrine (Epi) may act
as a cotransmitter in sympathetic nerves, stimulating presynaptic beta
(2)-receptors and enhancing norepinephrine (NE) release. To examine ne
uronal Epi release, patients with congestive heart failure and hyperte
nsion and healthy subjects were examined with the isotope-dilution met
hod. At baseline, small cardiac and renal Epi spillovers were found in
patients. During intense supine exercise, cardiac NE and Epi spillove
rs increased concomitantly with similar magnitude, whereas no renal Ep
i spillover could be detected. Blockade of neuronal uptake 1 caused a
consistent decrease in both cardiac and renal fractional extractions o
f NE and Epi. The present study demonstrates baseline cardiorenal Epi
release in patients with congestive heart failure and renal Epi releas
e in hypertensive patients. Furthermore, Epi is removed by neuronal up
take in both the heart and kidney, and cardiac Epi spillover increases
during exercise. This study, in contrast to other results, provides e
vidence for cardiac neuronal Epi release.