Investigation into the positive inotropic effect of clondine in isolated hearts

  • A. Csongrady
  • W. Kobinger


Clonidine in doses 2.5–40 μg injected into the aortic cannula of isolated, perfused hearts of guinea pigs produced an increase in contraction amplitude. This positive inotropic effect was not antagonised by infusions of doberol (10 μg/min), phentolamine (10 μg/min) or pheniramine (50 μg/min), it was antagonised by burimamide (30 μg/min), a histamine H2 receptor blocking agent. Clonidine showed some similarities to histamine such as parallel dose-response curves and during infusions of burimamide the curve of clonidine was shifted in a way which indicated competitive inhibition. It is suggested therefore that the action of clonidine is due to stimulation of histamine H2 receptors.

Key words

Clonidine Burimamide Positive Inotropic Action Histamine H2 Receptor 


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Copyright information

© Springer-Verlag 1974

Authors and Affiliations

  • A. Csongrady
    • 1
  • W. Kobinger
    • 1
  1. 1.Department of PharmacologyArzneimittelforschung GmbHWienAustria

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