Cardiovascular Drugs and Therapy

, Volume 4, Issue 3, pp 723–730 | Cite as

In-vitro study of the effect of clentiazem on rabbit aorta and on myocardium

  • Hiroshi Narita
  • Robert Ginsburg
Calcium Antagonists


We evaluated the pharmacologic action of clentiazem, a newly synthesized diltiazem derivative, on isolated rabbit aorta and myocardium. In addition to its Ca2+ blocking action, clentiazem demonstrated both vasorelaxing and negative inotropic actions similar to diltiazem. The vasorelaxant action of clentiazem on the tonic phase of KCl-induced contraction (EC50=6.13×10−8 M) was 4.5 times more potent than diltiazem (EC50=2.77×10−7 M). However, the negative inotropic action of clentiazem (IC50=4.34×10−5 M) was similar to diltiazem (IC50=3.94×10−5 M). Selectivity ratios, comparing the effectiveness in cardiac muscle with aorta, were clentiazem (708) > diltiazem (142). In conclusion, clentiazem is a Ca2+ antagonist and demonstrates greater vasoselectivity than diltiazem. It also has a longer lasting action than diltiazem.

Key Words

calcium antagonist clentiazem diltiazem, vasorelaxation negative inotropic action 


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Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • Hiroshi Narita
    • 1
  • Robert Ginsburg
    • 1
  1. 1.Division of CardiologyStanford Medical CenterStanfordUSA

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