THE MODE OF ACTION OF IFENPRODIL TARTRATE IN ISOLATED CANINE CEREBRAL AND FEMORAL ARTERIES

  • 1 February 1987
    • journal article
    • research article
    • Vol. 285  (2) , 211-225
Abstract
Tension of isolated rings of cerebral and femoral arteries was measured isometrically and Ca2+ movement in these arteries was measured by 45Ca flux to study the mode of action of ifenprodil tartrate (IFT). IFT (10-7-10-4 M) induced relaxation in basilar and femoral arteries contracted by K+ (50 mM). During normoxia (O2 aeration) it induced contraction in arteries contracted by prostaglandin (PG)F2.alpha. (10-5 M), but induced relaxation during hypoxia (N2 aeration). In K+-induced contraction the relaxed tension induced by IFT was reversed by addition of Ca2+ in a dose-dependent manner. The IFT induced relaxation of femoral arteries contracted by K+ was attenuated in Ca2+-free solution containing 0.1 mM EGTA, and the effect of IFT on basilar and femoral arteries contracted by PGF2.alpha. was reversed. IFT inhibited K+-induced Ca2+ uptake in cerebral and femoral arteries. IFT enhanced PGF2.alpha.-induced Ca2+ uptake in cerebral arteries under normoxia, but inhibited it under hypoxia. The results suggest that the action of IFT may be due to alteration of Ca2+ utilization by vascular cells through blockade of potential-sensitive channels, and this action may reflect regional differences between arteries.