Several phenylethylamine compounds cause concentration-dependent contraction of isolated rat thoracic aorta, with varying potency: 2C-H (pD2 = 6.74) is most potent, followed by TMPEA (pD2 = 5.83), 2C-D (pD2 = 5.06), homoveratrylamine (pD2 = 4.46), and homopiperonylamine (pD2 = 4.19). At a concentration of 9.9 × 10⁻⁶ M, 2C-N acts as a competitive antagonist to serotonin in this tissue. Comparing these results with earlier findings for 2C-B, weak or partial agonistic activity or antagonism of aortic contraction appears to relate to the psychedelic properties reported in humans for phenylethylamines.
The compound 5-methoxy-N,N-dimethyltryptamine (MeODMT) strengthens noradrenergic signaling in the rat spinal cord through two distinct mechanisms: it facilitates the release of noradrenaline triggered by electrical stimulation and inhibits the breakdown of noradrenaline by monoamine oxidase (MAO), preferentially the A-type enzyme. The effect on basal noradrenaline outflow disappeared when MAO was blocked by pargyline, while the effect on evoked release was absent in the presence of metitepine or phentolamine. These findings indicate that MeODMT acts both as a release enhancer and a metabolism inhibitor to boost noradrenaline activity.