The electrophysiological and beta-blocking effects of mepindolol have been examined in isolated guinea-pig preparations and sheep cardiac Purkinje fibers. Mepindolol did not show selectivity for blocking the chronotropic and inotropic responses to isoprenaline on isolated guinea-pig preparations, and was practically equally potent in blocking the effect of isoprenaline on isolated guinea-pig trachea. Mepindolol 10(-7) M fully antagonized the positive chronotropic effect of isoprenaline (10(-7) M) in Purkinje fibers. However, normal automaticity, action potential characteristics, effective refractory period, membrane responsiveness of Purkinje fibers were unaffected by mepindolol up to 10(-6) M. On the whole, mepindolol appears to be a potent beta-blocker with no cardioselectivity, exerting membrane depressant effect only at concentrations 100-1000 times higher than those exerting effective beta-blockade.
In vitro evaluation of the beta-blocking and electrophysiological properties of mepindolol / Amerini S;Bini R;Cerbai E;Ledda F;Mantelli L;Mugelli A. - In: ARCHIVES INTERNATIONALES DE PHARMACODYNAMIE ET DE THERAPIE. - ISSN 0003-9780. - STAMPA. - 282:(1986), pp. 276-287.
In vitro evaluation of the beta-blocking and electrophysiological properties of mepindolol.
CERBAI, ELISABETTA;MUGELLI, ALESSANDRO
1986
Abstract
The electrophysiological and beta-blocking effects of mepindolol have been examined in isolated guinea-pig preparations and sheep cardiac Purkinje fibers. Mepindolol did not show selectivity for blocking the chronotropic and inotropic responses to isoprenaline on isolated guinea-pig preparations, and was practically equally potent in blocking the effect of isoprenaline on isolated guinea-pig trachea. Mepindolol 10(-7) M fully antagonized the positive chronotropic effect of isoprenaline (10(-7) M) in Purkinje fibers. However, normal automaticity, action potential characteristics, effective refractory period, membrane responsiveness of Purkinje fibers were unaffected by mepindolol up to 10(-6) M. On the whole, mepindolol appears to be a potent beta-blocker with no cardioselectivity, exerting membrane depressant effect only at concentrations 100-1000 times higher than those exerting effective beta-blockade.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.