Nitrendipine is a calcium channel blocker with marked vasodilator action.Target: Calcium ChannelNitrendipine is a dihydropyridine calcium channel blocker. It is used in the treatment of primary hypertension to decrease blood pressure. Nitrendipine blocked Ca2+ currents very potently, with half-block by subnanomolar concentrations. The concentration dependence of block had the form expected for 1:1 binding, with an apparent dissociation constant (Kd) of 0.36 nM. In contrast, when cells were held at hyperpolarized potentials, nitrendipine blocked Ca2+ currents much less potently (Kd approximately equal to 700 nM) [1, 2]. Nitrendipine, a potent analogue of nifedipine, binds in a reversible and saturable manner to partially purified guinea-pig heart membranes [3]. [3H]nitrendipine binding in smooth muscle is to a site which mediates the pharmacologic response [4].

References:
[1]. Bean, B.P., Nitrendipine block of cardiac calcium channels: high-affinity binding to the inactivated state. Proc Natl Acad Sci U S A, 1984. 81(20): p. 6388-92.
[2]. Peterson, B.Z., T.N. Tanada, and W.A. Catterall, Molecular determinants of high affinity dihydropyridine binding in L-type calcium channels. J Biol Chem, 1996. 271(10): p. 5293-6.
[3]. Bellemann, P., et al., [3H]-Nitrendipine, a potent calcium antagonist, binds with high affinity to cardiac membranes. Arzneimittelforschung, 1981. 31(12): p. 2064-7.
[4]. Bolger, G.T., et al., Characterization of binding of the Ca++ channel antagonist, [3H]nitrendipine, to guinea-pig ileal smooth muscle. J Pharmacol Exp Ther, 1983. 225(2): p. 291-309.