Einfluss von Iloprost, einem stabilen Prostazyklin-Analogon, auf die myokardiale Kontraktilität im Vergleich zu natürlichem Prostazyklin : Laborexperimentelle Untersuchung an humanem Herzgewebe und Gewebe aus Kaninchenherzen

Iloprost, a stable derivate of prostacyclin (epoprostenol), is known to diminish PVR. In addition, improvement of right ventricular function has been observed after inhaled administration. Direct inotropic actions are not studied until now. In the present experimental study the dose-dependent contractile response of human atrial and rabbit atrial and ventricular trabeculae to iloprost and epoprostenol was investigated. In the first series of tests the dose-dependent contractile response to stepwise increased iloprost concentrations was investigated. Developed force was continuously registered at a pacing frequency of 1 Hz at 37°C. Iloprost concentration was stepwise increased from 10-11 to 10-7 M. In the second series of tests the dose-dependent contractile response to stepwise increased epoprostenol was investigated. At first concentrations between 10-9 and 10-6 M were studied. Because of the rapid spontaneous decay of prostacyclin in solutions the positive inotropic effect was significant but short lasting. A dose-response- curve could not be acquired. Therefore in a third series of tests the contractile response to 10-6 M epoprostenol was investigated during 15 min after addition. Baseline values were 7,42 +/- 2,1 mN/mm2 for human atrial trabeculae and 13,23 +/- 2,1 mN/mm2 for rabbit trabeculae. Iloprost exerted a positive inotropic effect in 11 of 18 human trabeculae (“responders”). In 7 trabeculae no change in contractility was observed, despite a positive effect of recalcification. At higher concentrations aftercontractions were seen in 29% of all human trabeculae. In 9 of 17 rabbit ventricular trabeculae iloprost increased developed (“responders”), in 8 trabeculae no positive effect was achieved. Aftercontraction were not seen in rabbit trabeculae. Epoprostenol exerted a significant short lasting positive inotropic effect in each investigated muscle. Our data suggest that iloprost exerts direct positive inotropic effects in a subset of human atrial and rabbit right ventricular trabeculae. However, species-independent, a relevant number of trabeculae did not respond to iloprost. Further investigations concerning the underlying mechanism of iloprost induced positive inotropism are necessary.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2006

Author dc:creator

• Müller-Späth, Susanne

Contributors dc:contributor

• Buhre, Wolfgang Friedrich

• info:eu-repo/classification/ddc/610
• Medizin

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123417%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61793