Abstract
1. Amlodipine, a dihydropyridine derivative largely ionized at physiological pH, inhibited calcium channel currents in single vascular smooth muscle cells isolated from rabbit ear artery in a concentration-dependent manner. 2. Amlodipine inhibited the current-voltage relationship for calcium channel currents across the range of test potentials used. However, the effect of amlodipine was more marked on more depolarized test potentials. Amlodipine also shifted the steady-state inactivation curve for calcium channel currents in a hyperpolarized direction. 3. The potency of amlodipine as determined from the steady-state inhibition of calcium channel current induced by the drug was dependent on the holding potential of the cells. Use of a more depolarized holding potential increased the potency of amlodipine. 4. Onset of amlodipine-induced inhibition was relatively rapid at both -60 mV and -40 mV holding potential. The use of a more depolarized holding potential increased the rate of association of amlodipine. No recovery from amlodipine-induced inhibition was seen over a 20 min period following washout of the drug. 5. In addition to voltage-dependence, the action of amlodipine showed use-dependence, in that the effect of amlodipine was more marked when calcium channel currents were evoked frequently. Increasing the frequency of activation of calcium channel currents did not alter the apparent onset rate of amlodipine-induced inhibition, but increased the degree of inhibition achieved by the drug. 6. The electrophysiological properties of amlodipine, particularly its voltage-dependence are probably important determinants of its action in vivo.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aaronson P. I., Bolton T. B., Lang R. J., MacKenzie I. Calcium currents in single isolated smooth muscle cells from the rabbit ear artery in normal-calcium and high-barium solutions. J Physiol. 1988 Nov;405:57–75. doi: 10.1113/jphysiol.1988.sp017321. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bean B. P. Nitrendipine block of cardiac calcium channels: high-affinity binding to the inactivated state. Proc Natl Acad Sci U S A. 1984 Oct;81(20):6388–6392. doi: 10.1073/pnas.81.20.6388. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bean B. P., Sturek M., Puga A., Hermsmeyer K. Calcium channels in muscle cells isolated from rat mesenteric arteries: modulation by dihydropyridine drugs. Circ Res. 1986 Aug;59(2):229–235. doi: 10.1161/01.res.59.2.229. [DOI] [PubMed] [Google Scholar]
- Benham C. D., Bolton T. B. Spontaneous transient outward currents in single visceral and vascular smooth muscle cells of the rabbit. J Physiol. 1986 Dec;381:385–406. doi: 10.1113/jphysiol.1986.sp016333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bolton T. B. Mechanisms of action of transmitters and other substances on smooth muscle. Physiol Rev. 1979 Jul;59(3):606–718. doi: 10.1152/physrev.1979.59.3.606. [DOI] [PubMed] [Google Scholar]
- Burges R. A., Gardiner D. G., Gwilt M., Higgins A. J., Blackburn K. J., Campbell S. F., Cross P. E., Stubbs J. K. Calcium channel blocking properties of amlodipine in vascular smooth muscle and cardiac muscle in vitro: evidence for voltage modulation of vascular dihydropyridine receptors. J Cardiovasc Pharmacol. 1987 Jan;9(1):110–119. [PubMed] [Google Scholar]
- Bäuerle H. D., Seelig J. Interaction of charged and uncharged calcium channel antagonists with phospholipid membranes. Binding equilibrium, binding enthalpy, and membrane location. Biochemistry. 1991 Jul 23;30(29):7203–7211. doi: 10.1021/bi00243a023. [DOI] [PubMed] [Google Scholar]
- Cheung D. W. Membrane potential of vascular smooth muscle and hypertension in spontaneously hypertensive rats. Can J Physiol Pharmacol. 1984 Aug;62(8):957–960. doi: 10.1139/y84-160. [DOI] [PubMed] [Google Scholar]
- Ehara T., Daufmann R. The voltage- and time-dependent effects of (-)-verapamil on the slow inward current in isolated cat ventricular myocardium. J Pharmacol Exp Ther. 1978 Oct;207(1):49–55. [PubMed] [Google Scholar]
- Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
- Harder D. R., Hermsmeyer K. Membrane mechanisms in arterial hypertension. Hypertension. 1983 Jul-Aug;5(4):404–408. doi: 10.1161/01.hyp.5.4.404. [DOI] [PubMed] [Google Scholar]
- Harder D. R. Heterogeneity of membrane properties in vascular muscle cells from various vascular beds. Fed Proc. 1983 Feb;42(2):253–256. [PubMed] [Google Scholar]
- Herbette L. G., Chester D. W., Rhodes D. G. Structural analysis of drug molecules in biological membranes. Biophys J. 1986 Jan;49(1):91–94. doi: 10.1016/S0006-3495(86)83605-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hering S., Beech D. J., Bolton T. B. A simple method of fast extracellular solution exchange for the study of whole-cell or single channel currents using patch-clamp technique. Pflugers Arch. 1987 Oct;410(3):335–337. doi: 10.1007/BF00580285. [DOI] [PubMed] [Google Scholar]
- Hering S., Bolton T. B., Beech D. J., Lim S. P. Mechanism of calcium channel block by D600 in single smooth muscle cells from rabbit ear artery. Circ Res. 1989 May;64(5):928–936. doi: 10.1161/01.res.64.5.928. [DOI] [PubMed] [Google Scholar]
- Honoré E., Amédée T., Martin C., Dacquet C., Mironneau C., Mironneau J. Calcium channel current and its sensitivity to (+) isradipine in cultured pregnant rat myometrial cells. An electrophysiological and a binding study. Pflugers Arch. 1989 Aug;414(4):477–483. doi: 10.1007/BF00585060. [DOI] [PubMed] [Google Scholar]
- Hughes A. D., Hering S., Bolton T. B. The action of caffeine on inward barium current through voltage-dependent calcium channels in single rabbit ear artery cells. Pflugers Arch. 1990 Jun;416(4):462–466. doi: 10.1007/BF00370755. [DOI] [PubMed] [Google Scholar]
- Kass R. S., Arena J. P. Influence of pHo on calcium channel block by amlodipine, a charged dihydropyridine compound. Implications for location of the dihydropyridine receptor. J Gen Physiol. 1989 Jun;93(6):1109–1127. doi: 10.1085/jgp.93.6.1109. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuga T., Sadoshima J., Tomoike H., Kanaide H., Akaike N., Nakamura M. Actions of Ca2+ antagonists on two types of Ca2+ channels in rat aorta smooth muscle cells in primary culture. Circ Res. 1990 Aug;67(2):469–480. doi: 10.1161/01.res.67.2.469. [DOI] [PubMed] [Google Scholar]
- Mason R. P., Campbell S. F., Wang S. D., Herbette L. G. Comparison of location and binding for the positively charged 1,4-dihydropyridine calcium channel antagonist amlodipine with uncharged drugs of this class in cardiac membranes. Mol Pharmacol. 1989 Oct;36(4):634–640. [PubMed] [Google Scholar]
- McCarthy R. T., Cohen C. J. Nimodipine block of calcium channels in rat vascular smooth muscle cell lines. Exceptionally high-affinity binding in A7r5 and A10 cells. J Gen Physiol. 1989 Oct;94(4):669–692. doi: 10.1085/jgp.94.4.669. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nayler W. G. The role of oxygen radicals during reperfusion. J Cardiovasc Pharmacol. 1992;20 (Suppl 5):S14–S17. [PubMed] [Google Scholar]
- Nelson M. T., Worley J. F. Dihydropyridine inhibition of single calcium channels and contraction in rabbit mesenteric artery depends on voltage. J Physiol. 1989 May;412:65–91. doi: 10.1113/jphysiol.1989.sp017604. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rhodes D. G., Sarmiento J. G., Herbette L. G. Kinetics of binding of membrane-active drugs to receptor sites. Diffusion-limited rates for a membrane bilayer approach of 1,4-dihydropyridine calcium channel antagonists to their active site. Mol Pharmacol. 1985 Jun;27(6):612–623. [PubMed] [Google Scholar]
- Sagan S., Corbett A. D., Amiche M., Delfour A., Nicolas P., Kosterlitz H. W. Opioid activity of dermenkephalin analogues in the guinea-pig myenteric plexus and the hamster vas deferens. Br J Pharmacol. 1991 Oct;104(2):428–432. doi: 10.1111/j.1476-5381.1991.tb12446.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanguinetti M. C., Kass R. S. Voltage-dependent block of calcium channel current in the calf cardiac Purkinje fiber by dihydropyridine calcium channel antagonists. Circ Res. 1984 Sep;55(3):336–348. doi: 10.1161/01.res.55.3.336. [DOI] [PubMed] [Google Scholar]
- Schwarz J. R., Ulbricht W., Wagner H. H. The rate of action of tetrodotoxin on myelinated nerve fibres of Xenopus laevis and Rana esculenta. J Physiol. 1973 Aug;233(1):167–194. doi: 10.1113/jphysiol.1973.sp010304. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seelig J., Ganz P. Nonclassical hydrophobic effect in membrane binding equilibria. Biochemistry. 1991 Sep 24;30(38):9354–9359. doi: 10.1021/bi00102a031. [DOI] [PubMed] [Google Scholar]
- Stekiel W. J., Contney S. J., Lombard J. H. Small vessel membrane potential, sympathetic input, and electrogenic pump rate in SHR. Am J Physiol. 1986 Apr;250(4 Pt 1):C547–C556. doi: 10.1152/ajpcell.1986.250.4.C547. [DOI] [PubMed] [Google Scholar]
- Terada K., Nakao K., Okabe K., Kitamura K., Kuriyama H. Action of the 1,4-dihydropyridine derivative, KW-3049, on the smooth muscle membrane of the rabbit mesenteric artery. Br J Pharmacol. 1987 Nov;92(3):615–625. doi: 10.1111/j.1476-5381.1987.tb11364.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsien R. W. Calcium channels in excitable cell membranes. Annu Rev Physiol. 1983;45:341–358. doi: 10.1146/annurev.ph.45.030183.002013. [DOI] [PubMed] [Google Scholar]
- van Breemen C., Saida K. Cellular mechanisms regulating [Ca2+]i smooth muscle. Annu Rev Physiol. 1989;51:315–329. doi: 10.1146/annurev.ph.51.030189.001531. [DOI] [PubMed] [Google Scholar]