Cardiovascular effects of lepadiformine, an alkaloid isolated from the ascidians Clavelina lepadiformis (Muller) and C-moluccensis (Sluiter)

M. Juge 1 N. Grimaud 1 J.-F. Biard 2 Martin-Pierre Sauviat 3 M. Nabil 4 J.-F. Verbist 2 Jean-Yves Petit 1
1 Département de Pharmacologie
2 ISOMer-SMAB
3 LOA - Laboratoire d'optique appliquée
4 ISERST
Abstract : The effects of lepadiformine, a natural marine alkaloid isolated from the ascidians Clavelina lepadifonllis (Muller) and C. moluccensis (Sluiter), were studied in vivo by arterial blood pressure (aBP) recordings and electrocardiograms (ECG) in anaesthetised rats and in situ by peripheral vascular pressure recordings on perfused rabbit ear. Transmembrane resting (RP) and action (AP) potentials were also recorded by intracellular microelectrodes on electrically stimulated left ventricular papillary muscle and spontaneously beating atrium isolated from rat and frog hearts, respectively. Intravenous injection of lepadiformine (6 mg/kg) produced marked bradycardia and a lengthening of ECG intervals as well as a transient decrease of aBP, which rapidly returned to normal. The decrease of aBP may have been related to a vasoconstrictor effect observed in the perfused ear experiment. Lepadiformine did not alter RP, bur significantly lengthened the repolarising phase of AP in rat papillary muscle and frog atrium. Lepadiformine also mimicked the effect of Ba2+ (0.2 mM) on the rat AP repolarising phase. Moreover, the lengthening of the AP in frog atrium induced by lepadiformine still developed after the delayed outward K+ current (I-K) was blocked by tetraethylammonium (10 mM). These observations suggest that lepadiformine-induced lengthening of AP duration was not due to a decrease of I-K, but may reasonably be attributed to a reduction of the inward rectifying K+ current (I-K1). This blockade of I-K1 could account for the cardiovascular effects of lepadiformine in vivo and in vitro and suggests that lepadiformine: has antiarrhythmic properties. (C) 2001 Elsevier Science Ltd. AH rights reserved.
Document type :
Journal articles
Complete list of metadatas
https://hal-polytechnique.archives-ouvertes.fr/hal-00837022
Contributor : Denis Roura <>
Submitted on : Monday, July 1, 2013 - 10:26:42 PM
Last modification on : Wednesday, July 3, 2019 - 10:48:02 AM

Links full text

istex

Identifiers

Collections

X-LOA | X | ENSTA | PARISTECH | ENSTA_LOA | X-DEP-PHYS

Citation

M. Juge, N. Grimaud, J.-F. Biard, Martin-Pierre Sauviat, M. Nabil, et al.. Cardiovascular effects of lepadiformine, an alkaloid isolated from the ascidians Clavelina lepadiformis (Muller) and C-moluccensis (Sluiter). Toxicon, Elsevier, 2001, 39 (8), pp.1231. ⟨10.1016/S0041-0101(01)00079-4⟩. ⟨hal-00837022⟩

Export

BibTeX TEI DC DCterms EndNote

Share

Metrics

Record views

176

Contact

support.ccsd.cnrs.fr
hal.support@ccsd.cnrs.fr
Logo CCSD