AZINES AND DIAZINES AS POTENTIAL HISTAMIN E H-3 RECEPTOR ANTAGONISTS

In search of structure-activity relationships among histamine H-3-rece ptor antagonists the imidazole ring of known H-3-receptor antagonists was replaced by different heteroaromatic ring systems. Thus, azines an d diazines with ether (6-13) and carbamate (15-24) moieties as functio nal groups were synthesized. The obtained compounds did not show signi ficant H-3-receptor antagonist activity in vitro (rat brain cortex) or in vivo (mice brain). The new compounds were also screened for H-1-re ceptor antagonist activity on the isolated guinea-pig ileum and for H- 2-receptor antagonist activity on the isolated spontaneously beating g uinea-pig right atrium. The substances showed only weak antagonistic a ctivity at both histamine receptors, H-1 and H-2.