| Literature DB >> 1657688 |
P Vassilev1, D Staneva-Stoytcheva, V Mutafova-Yambolieva.
Abstract
1. The specific effects of histamine were studied on rat vas deferens contractions induced by electrical field stimulation (0.1 Hz, 1 pulse, 1 msec duration, supramaximal voltage). 2. Histamine (5 x 10(-7)-10(-4) M) inhibited the electrically-evoked contractions (EEC). This effect was unchanged after the H1-receptor antagonist diphenhydramine (5 x 10(-6) M) and was decreased after the H2-receptor antagonist cimetidine (10(-5) M). 3. Betahistine, described as H1-agonist (in guinea pig ileum) and H3-autoreceptor antagonist (in rat cerebral cortex) slightly decreased the EEC, but competitively inhibited the histamine effect. 4. The results obtained suggest the existence of a specific third type presynaptic H-receptors in rat vas deferens, which are pharmacologically similar to the presynaptic H3-autoreceptors in rat cerebral cortex.Entities:
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Year: 1991 PMID: 1657688 DOI: 10.1016/0306-3623(91)90070-m
Source DB: PubMed Journal: Gen Pharmacol ISSN: 0306-3623