Possible Interaction: Leucine and Nifedipine

“ Nifedipine caused a significant increase in FEV1 (0.21 +/- 0.08 SEM L ) at 40 min after administration of the drug.”

“When steady-state inactivation curves for the L current were fitted with a Boltzmann equation, this … mV. In contrast, the T current inactivated with a V1/2 of -80+/-3 mV. The L currents … by nifedipine (ED50=159+/-54 nM) and Ni2+ (ED50=… external Ca2+ was substituted with Ba2+.”

“Nifedipine, at a concentration of 5 microM, was used to block ICa,L. At this concentration, nifedipine selectively blocked ICa, L for 81% without affecting the T-type calcium current (ICa,T), the fast sodium current, the delayed rectifier current (IK), and the hyperpolarization-activated inward current.”

“The L-type Ca2+ channel blockers verapamil and nifedipine inhibited NE-stimulated incorporation of [3H]leucine in myocytes and [3H]thymidine in fibroblasts, and these effects were not additive with those of ANP, SNAP, or 8-bromo-cGMP.”

“In patch‐clamped cells, using the switcher to apply 20 microM nifedipine (an L‐type Ca2+ current (ICa,L) blocker) 4 s before a depolarization to +10 mV reduced the amplitude of ICa, L to 10.25 +/‐ 2.25% of control (mean +/‐ S.E.M., n = 7 cells).”

“When ICa, L was blocked with nifedipine , the fraction of Ca2+i transient which remained increased with more positive test potential and higher internal Na+.”

“ICa L but not ICa,T was blocked by 1 microM nifedipine.”

“Because calcium channel antagonists such as D600, nifedipine and diltiazem6,7 inhibit L currents5,8,9, we examined their effect on GTP-γ-S-modified currents.”