Subtype determination of presynaptic α2-autoreceptors in the rabbit pulmonary artery and human saphenous vein was written by Molderings, G. J.;Gothert, M.. And the article was included in Naunyn-Schmiedeberg’s Archives of Pharmacology in 1995.Category: thiazole This article mentions the following:
The pharmacol. properties of the presynaptic α2-autoreceptors mediating inhibition of noradrenaline release were investigated in human saphenous vein and rabbit pulmonary artery. Segments of these blood vessels were incubated with [3H]noradrenaline and subsequently superfused with physiol. salt solution containing uptake1 and uptake2 blockers. The potencies of α2-adrenoceptor antagonists in facilitating (pEC40) the elec. (2Hz) evoked tritium overflow were determined The order of potency and potency ratios of α2-adrenoceptor antagonists in facilitating (pEC40) the elec. (2Hz) evoked tritium overflow were determined The order of potency and potency rations of α2-adrenoceptor antagonists obtained in the experiments were compared with the corresponding order of affinity and affinity rations from radioligand binding studies in tissues and cells expressing only 1 of the α2-adrenoceptor subtypes. In the rabbit pulmonary artery, oxymetazoline was a highly potent agonist at presynaptic α2-adrenoceptors, as reflected by its ability to inhibit at low concentrations the elec. evoked tritium overflow. However, in the human saphenous vein oxymetazoline behaved as a partial agonist, which, interaction experiments with the α2-adrenoceptor agonist B-HT 920 (2-amino-6-allyl-5-6,7,8-tetrahydro-4H-thiazolo-[4,5-d]-azephine), exhibited high potency in antagonizing the inhibitory effect of the latter drug on tritium overflow. Prazosin given alone at concentrations ≤1 μM did not affect tritium overflow. The data obtained with oxymetazoline and prazosin make it very improbable that the α2-autoreceptors on the sympathetic nerves in both tissues are of the α2B– or α2C– subtype. In both blood vessels, rauwolscine given alone was highly potent in facilitating the elec. evoked overflow. In agreement with this, rauwolscine exhibited high potency in antagonizing the inhibitory effect of oxymetazoline on tritium overflow in the rabbit pulmonary artery and of B-HT 920 in the human saphenous vein. The ratio phentolamine/rauwolscine calculated from their potencies in increasing the elec. evoked tritium overflow was also used to discriminate between the various a2-adrenoceptor subtypes. Comparisons of this potency ratio with the corresponding affinity ratios for α2-adrenergic binding sites on HT 29 cells, human platelets, bovine pineal gland, rat submaxillary gland, and cell lines transfected with the human α2 genes indicates that in the rabbit pulmonary artery and human saphenous vein the pharmacol. characteristics of the autoreceptors conform best to those of α2A-adrenoceptors. Finally, in both blood vessels the potencies of the antagonists BDF 6143 (4-chloro-2-(2-imidazolin-2-ylamino)-isoindoline), rauwolscine, corynanthine, phentolamine, idazoxan, SKF 104078 (6-chloro-9-[(3-methyl-2-butenyl) oxyl]-3-methyl-1-1H-2,3,4,5-tetrahydro-3-benzazepine), and/or tolazoline in facilitating evoked noradrenaline, and/or tolazoline in facilitating evoked noradrenaline release was determined The potencies of these drugs which can discriminate between α2A– and α2D-adrenoceptors (but not between these and α2B/2C-adrenoceptors) were correlated significantly with their affinities for α2A, but not α2D, sites in radioligand binding studies. Apparently, the sympathetic nerves of the human saphenous vein and rabbit pulmonary artery are endowed with α2-autoreceptors of the α2A subtype. In the experiment, the researchers used many compounds, for example, 6-Allyl-5,6,7,8-tetrahydro-4H-thiazolo[4,5-d]azepin-2-amine dihydrochloride (cas: 36085-73-1Category: thiazole).
6-Allyl-5,6,7,8-tetrahydro-4H-thiazolo[4,5-d]azepin-2-amine dihydrochloride (cas: 36085-73-1) belongs to thiazole derivatives. Thiazoles frequently appear in peptide studies. Thiazoles can also be used as protected formyl groups, which can be released in later stages of complex natural product synthesis. Thiazole sulfonation occurs only under forcing conditions: the action of oleum at 250 °C for 3 hours in the presence of mercury(II) sulfate leads to 65% formation of 5-thiazole sulfonic acid.Category: thiazole
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica