Journal of Comparative Physiology B

, 176:429

Inhibitory effects of various L-type and T-type calcium antagonists on electrically generated, potassium-induced and carbachol-induced contractions of porcine detrusor muscle

Authors

    • Department of UrologyUniversity Hospital Mannheim
  • Heng  Li
    • Department of UrologyUniversity Hospital Mannheim
  • Sigrun Langbein
    • Department of UrologyUniversity Hospital Mannheim
  • Stefan  Kamp
    • Department of UrologyUniversity Hospital Mannheim
  • Sergio  Guzman
    • Department of UrologyUniversity Hospital Mannheim
  • Stephan  Bross
    • Department of UrologyUniversity Hospital Mannheim
Original Paper

DOI: 10.1007/s00360-006-0064-0

Cite this article as:
Badawi, J.K., Li, H., Langbein, S. et al. J Comp Physiol B (2006) 176: 429. doi:10.1007/s00360-006-0064-0

Abstract

The inhibitory effects of different calcium antagonists on contractions of isolated porcine detrusor muscle were investigated. Suppression of the maximum potassium-induced contraction and electrically generated contractions by nifedipine, verapamil and diltiazem were investigated. Furthermore, concentration–response curves of carbachol after pretreatment with the L-type antagonists nifedipine, verapamil, diltiazem, nimodipine and the T-type antagonist mibefradil at different concentrations were performed. Nifedipine significantly reduced the potassium-induced maximum contraction to 89, 60, 21, 8 and 4% (10−9–10−5 M). Verapamil and diltiazem significantly reduced it to 64, 30 and 5% (10−7–10−5 M) or 79, 27, 7 and 1% (10−7–10−4 M), respectively. Nifedipine, verapamil and diltiazem significantly reduced the electrically generated contraction to 55, 36, 34 and 25% (10−7–10−4 M), 71, 32 and 2% (10−6–10−4 M), 96, 78, 38 and 5% (10−7–10−4 M), respectively. pD2 values of nifedipine, verapamil and diltiazem amounted to 7.07, 5.56 and 5.40 and differed significantly. After pretreatment with nifedipine at 10−6 M, the concentration–response curve of carbachol was nearly suppressed. The effects of nimodipine, verapamil and diltiazem were smaller. Mibefradil caused only at 10−5 M a significant reduction. All investigated L-type calcium antagonists were strong inhibitors of the examined contractions. Nifedipine showed the biggest inhibitory effect.

Keywords

T-type and L-type calcium antagonistIsolated porcine detrusor muscleOrgan bathPigUrinary bladder smooth muscle

Copyright information

© Springer-Verlag 2006