caa a22 4500 469049251 CHVBK 20180323132825.0 cr unu---uuuuu 170328e19920301xx s 000 0 eng 10.1007/BF00175981 doi (NATIONALLICENCE)springer-10.1007/BF00175981 Bronchodilator action of an agonist for histamine H3-receptors in guinea pig perfused bronchioles and lung parenchymal strips [Elektronische Daten] [Jean-Luc Burgaud, James Javellaud, Nicole Oudart] Isolated guinea pig perfused bronchioles and lung parenchymal strips were examined as an in vitro model for assessment of the direct effect of pharmacologic agents on the airway smooth muscle. The experiments were performed with a perfusion technique in bronchioles, the input pressure being measured as an index of the state of dilation, while changes in tension of the lung parenchymal strips were measured with an isometric force transducer. In both preparations, histamine and acetylcholine elicited dose-related contractile responses whereas fenoterol induced a concentration-dependent relaxation. After the 3 agonists' activities were compared in these 2 preparations, we tested the intrinsic effects of a specific H3 agonist, (R)α-methylhistamine ([R]α-MeHA). Statistical analysis was by Student's t test on the Emax (expressed as a percentage of 10−4 M papaverine relaxation), EC50, and slopes of regression lines calculated from the concentration-response curves plotted for (R)α-MeHA alone or in presence of antagonists. Our results showed that (R)α-MeHA induced a concentration-dependent relaxation of perfused bronchioles and lung parenchymal strips competitively inhibited by 10−7 M thioperamide (H3-antagonist), whereas 10−5 M cimetidine (H2-antagonist) failed to prevent this effect. These results suggest the presence of H3-histaminergic dilatory receptors in the guinea pig airway. Springer-Verlag, 1992 H3 receptor sites nationallicence (R)α-methylhistamine nationallicence Bronchioles nationallicence Lung parenchyma nationallicence Burgaud Jean-Luc Laboratoire de Pharmacologie, UFR de Pharmacie, 2, rue du Docteur Marcland, 87025, Limoges Cedex, France aut Javellaud James Laboratoire de Pharmacologie, UFR de Pharmacie, 2, rue du Docteur Marcland, 87025, Limoges Cedex, France aut Oudart Nicole Laboratoire de Pharmacologie, UFR de Pharmacie, 2, rue du Docteur Marcland, 87025, Limoges Cedex, France aut Lung Springer-Verlag 170/2(1992-03-01), 95-108 0341-2040 170:2<95 1992 170 408 https://doi.org/10.1007/BF00175981 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00175981 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Burgaud Jean-Luc Laboratoire de Pharmacologie, UFR de Pharmacie, 2, rue du Docteur Marcland, 87025, Limoges Cedex, France aut NATIONALLICENCE 700 1- Javellaud James Laboratoire de Pharmacologie, UFR de Pharmacie, 2, rue du Docteur Marcland, 87025, Limoges Cedex, France aut NATIONALLICENCE 700 1- Oudart Nicole Laboratoire de Pharmacologie, UFR de Pharmacie, 2, rue du Docteur Marcland, 87025, Limoges Cedex, France aut NATIONALLICENCE 773 0- Lung Springer-Verlag 170/2(1992-03-01), 95-108 0341-2040 170:2<95 1992 170 408 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer