Modulation of 3 H‐noradrenaline release by presynaptic opioid, cannabinoid and bradykinin receptors and β‐adrenoceptors in mouse tissues

• Published in: British journal of pharmacology 2009-01, Vol.130 (2), p.321-330
• Main Authors: Trendelenburg, A U, Cox, S L, Schelb, V, Klebroff, W, Khairallah, L, Starke, K
• Format: Article
• Language: English
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0703305

Release‐modulating opioid and cannabinoid (CB) receptors, β‐adrenoceptors and bradykinin receptors at noradrenergic axons were studied in mouse tissues (occipito‐parietal cortex, heart atria, vas deferens and spleen) preincubated with 3 H‐noradrenaline. Experiments using the OP 1 receptor‐selective agonists DPDPE and DSLET, the OP 2 ‐selective agonists U50488H and U69593, the OP 3 ‐selective agonist DAMGO, the ORL 1 receptor‐selective agonist nociceptin, and a number of selective antagonists showed that the noradrenergic axons innervating the occipito‐parietal cortex possess release‐inhibiting OP 3 and ORL 1 receptors, those innervating atria OP 1 , ORL 1 and possibly OP 3 receptors, and those innervating the vas deferens all four opioid receptor types. Experiments using the non‐selective CB agonists WIN 55,212‐2 and CP 55,940 and the CB 1 ‐selective antagonist SR 141716A indicated that the noradrenergic axons of the vas deferens possess release‐inhibiting CB 1 receptors. Presynaptic CB receptors were not found in the occipito‐parietal cortex, in atria or in the spleen. Experiments using the non‐selective β‐adrenoceptor agonist isoprenaline and the β 2 ‐selective agonist salbutamol, as well as subtype‐selective antagonists, demonstrated the occurrence of release‐enhancing β 2 ‐adrenoceptors at the sympathetic axons of atria and the spleen, but demonstrated their absence in the occipito‐parietal cortex and the vas deferens. Experiments with bradykinin and the B 2 ‐selective antagonist Hoe 140 showed the operation of release‐enhancing B 2 receptors at the sympathetic axons of atria, the vas deferens and the spleen, but showed their absence in the occipito‐parietal cortex. The experiments document a number of new presynaptic receptor locations. They confirm and extend the existence of marked tissue and species differences in presynaptic receptors at noradrenergic neurons. British Journal of Pharmacology (2000) 130 , 321–330; doi: 10.1038/sj.bjp.0703305