The evidence for histamine H₃ receptor‐mediated endothelium‐dependent relaxation in isolated rat aorta

Abstract

The presence of histamine H3 receptors was evaluated on the rat aorta endothelium. In the presence of pyrilamine (1 nM, 7 nM, 10 nM) or thioperamide (1 nM, 10 nM, 30 nM) the concentration–response curve for histamine-induced (0.1 nM − 0.01 mM) endothelium-dependent rat aorta relaxation was shifted to the right without significant change of the Emax indicating competitive antagonism by pyrilamine (pA2 = 9.33 ± 0.34, slope = 1.09 ± 0.36) or thioperamide (pA2 =9.31 ± 0.16, slope=0.94 ± 0.10). Cimetidine (1 μM) did not influence histamine-induced endothelium-dependent rat aorta relaxation. In the presence of thioperamide (1 nM, 10 nM, 30 nM) the concentration–response curve for (R)α-MeHA-induced (0.1 nM − 0.01 mM) endothelium-dependent relaxation was shifted to the right without significant change of Emax indicated competitive antagonism by thioperamide (pA2 = 9.21 ± 0.4, slope = 1.03 ± 0.35). Pyrilamine (100 nM) or cimetidine (1 μM) did not influence (R)α-MeHA-induced endothelium-dependent rat aorta relaxation. These results suggest the presence of a heterogenous population of histamine receptors, H1 and H3, on rat aorta endothelium.

Potentiation of NF‐κB‐dependent transcription and inflammatory mediator release by histamine in human airway epithelial cells

“…However, in our current study, the apparent affinity of the H 1 receptor antagonist mepyramine was ∼10‐fold higher for blocking histamine‐induced NF‐κB‐dependent transcription (p A 2 =9.91) than for suppressing the release of IL‐6 and IL‐8 (p A 2 =8.78 and 8.99, respectively). The p A 2 of mepyramine on NF‐κB‐dependent transcription is broadly consistent with previously published values (Tayo and Bevan, 1986; Impicciatore et al , 1987; Kamei et al , 1990; Djuric and Andjelkovic, 1995). However, the lower affinity of mepyramine, when IL‐6 and IL‐8 release is used as a measure, suggests that while the enhancement of NF‐κB‐dependent transcription is entirely H 1 receptor‐dependent, the enhancement by histamine of IL‐8 and, particularly, IL‐6 release may also involve additional histamine receptor subtypes.…”

Φλεγμονώδης Απάντηση Σε Πειραματική Χειρουργική Παρέμβαση Επί Αγγείων Υπό Φυσιολογικό Και Τροποποιημένο Υπόστρωμα

“…Πρόσφατες μελέτες έδειξαν ότι οι Η 3 υποδοχείς ρυθμίζουν τον πόνο σε περιφερικά αγγεία, σε αγγεία κλάδους της σπονδυλικής και του εγκεφάλου(Hough and Rice 2011). Οι Η 3 υποδοχείς στο ενδοθήλιο της αορτής επιδρούν στην εξαρτώμενη από το ενδοθήλιο διαστολή της αορτής(Djuric and Andjelkovic 1995;Djuric et al 1996).Φαρμακολογίας (αριθμός αδείας 31 ΕΕ ΕΠ 010) για 10-15 ημέρες.2.1.2. Χημικά αντιδραστήρια και φαρμακολογικά δραστικές ουσίες…”