Do cannabinoids exhibit a tyramine-like effect?
Source
Department of Pharmacology and Toxicology, University of Bonn, Sigmund-Freud-Str. 25, 53127, Bonn, Germany.
Abstract
The major constituent of the cannabis plant, Δ9-tetrahydrocannabinol, has stimulatory and depressant effects on cardiovascular functions. There is evidence from an in vivo study on the urethane-anaesthetized rat that part of the stimulatory effects is related to a tyramine-like activity. In the present study, we examined whether Δ9-tetrahydrocannabinol induces carrier-mediated noradrenaline release in vitro. The study was extended to another phytocannabinoid, cannabidiol, to the synthetic cannabinoids CP 55,940 and WIN 55,212-2 and to the endocannabinoids anandamide and 2-arachidonoyl glycerol. Tissue pieces of the renal cortex from the mouse and the rat were preincubated with 3H-noradrenaline and superfused. The effect of the cannabinoids on basal 3H-noradrenaline release was studied. Tyramine served as a positive control. In the mouse kidney, basal 3H-noradrenaline release was increased by tyramine 0.1, 1 and 10 μM by 39, 91 and 212 %, respectively, and, in the rat kidney, 3H-noradrenaline release was increased by tyramine 10 μM by 158 %. All effects were abolished by desipramine 1 μM, an inhibitor of the neuronal noradrenaline transporter. The cannabinoids at 0.1, 1 and 10 μM (CP 55,940 at 0.1, 1 and 3.2 μM) did not affect 3H-noradrenaline release in the mouse kidney. The highest concentration of the cannabinoids (10 μM and in the case of CP 55,940 3.2 μM) also failed to affect 3H-noradrenaline release in the rat kidney. In conclusion, thecannabinoids Δ9-tetrahydrocannabinol, cannabidiol, CP 55,940, WIN 55,212-2, anandamide and 2-arachidonoyl glycerol do not possess a tyramine-like effect on noradrenaline release.
- PMID:
- 23900610
- [PubMed – as supplied by publisher]