Modulation of (3)H-noradrenaline release by presynaptic opioid, cannabinoid and bradykinin receptors and beta-adrenoceptors in mouse tissues.
Release-modulating opioid and cannabinoid (CB) receptors, beta-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 beta-adrenoceptor agonist isoprenaline and the beta(2)-selective agonist salbutamol, as well as subtype-selective antagonists, demonstrated the occurrence of release-enhancing beta(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.
Trendelenburg
A U
AU
Pharmakologisches Institut, Universität Freiburg, Hermann-Herder-Strasse 5, D-79104 Freiburg i. Br., Germany. trendele@ruf.uni-freiburg.de
Cox
S L
SL
Schelb
V
V
Klebroff
W
W
Khairallah
L
L
Starke
K
K
D000818:Animals; D001369:Axons / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009638:Norepinephrine / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D018002:Receptors, Bradykinin / Q000378:metabolism*; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000378:metabolism*; D011957:Receptors, Opioid / Q000378:metabolism*; D017661:Receptors, Presynaptic / Q000378:metabolism*; D013045:Species Specificity; D013154:Spleen / Q000378:metabolism; D014316:Tritium; D014649:Vas Deferens / Q000378:metabolism
D011943:Receptors, Adrenergic, beta; D018002:Receptors, Bradykinin; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D011957:Receptors, Opioid; D017661:Receptors, Presynaptic; D014316:Tritium; D009638:Norepinephrine