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. 1989 May;97(1):256–262. doi: 10.1111/j.1476-5381.1989.tb11949.x

(+)-[3H]-PN 200-110 binding to cell membranes and intact strips of portal vein smooth muscle: characterization and modulation by membrane potential and divalent cations.

C Dacquet 1, G Loirand 1, L Rakotoarisoa 1, C Mironneau 1, J Mironneau 1
PMCID: PMC1854475  PMID: 2524235

Abstract

1. Specific binding of the calcium-antagonist dihydropyridine derivative, (+)-[3H]-PN 200-110 (isradipine), to cell membranes of equine portal vein smooth muscle was compared with binding to intact strips isolated from rat portal veins. 2. Specific binding to vascular smooth muscle membranes was of high affinity, saturable and reversible. The dissociation constant obtained from association and dissociation kinetics of (+)-[3H]-PN 200-110 was similar to that obtained from equilibrium binding and competition experiments. 3. Specific binding of (+)-[3H]-PN 200-110 was completely displaced by unlabelled dihydropyridines. Among other calcium antagonists, D888 and (+)-cis-diltiazem partially inhibited the binding at 25 degrees C. At 37 degrees C, only (+)-cis-diltiazem stimulated the binding. LaCl3, CdCl2, NiCl2, CoCl2 had inhibitory effects, whereas KCl and NaCl had no effect. 4. When intact strips of portal vein were incubated in high external potassium concentrations for 30 min, the Kd was lowered to 0.04 +/- 0.01 nM from the control value of 0.14 +/- 0.02 nM (n = 5), thereby indicating that (+)-[3H]-PN 200-110 bound to voltage-dependent calcium channels, with a higher affinity, in the depolarized state. 5. When external Ca2+ was removed or substituted with Ba2+ or Sr2+, Kd values increased suggesting that the dihydropyridine binding to intact strips was modulated by binding of Ca2+ ions to voltage-dependent calcium channels.

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Selected References

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  1. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  2. Cheng Y., Prusoff W. H. Relationship between the inhibition constant (K1) and the concentration of inhibitor which causes 50 per cent inhibition (I50) of an enzymatic reaction. Biochem Pharmacol. 1973 Dec 1;22(23):3099–3108. doi: 10.1016/0006-2952(73)90196-2. [DOI] [PubMed] [Google Scholar]
  3. Dacquet C., Mironneau C., Mironneau J. Effects of calcium entry blockers on calcium-dependent contractions of rat portal vein. Br J Pharmacol. 1987 Sep;92(1):203–211. doi: 10.1111/j.1476-5381.1987.tb11313.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dacquet C., Pacaud P., Loirand G., Mironneau C., Mironneau J. Comparison of binding affinities and calcium current inhibitory effects of a 1,4-dihydropyridine derivative (PN 200-110) in vascular smooth muscle. Biochem Biophys Res Commun. 1988 May 16;152(3):1165–1172. doi: 10.1016/s0006-291x(88)80407-8. [DOI] [PubMed] [Google Scholar]
  5. Fosset M., Jaimovich E., Delpont E., Lazdunski M. [3H]nitrendipine receptors in skeletal muscle. J Biol Chem. 1983 May 25;258(10):6086–6092. [PubMed] [Google Scholar]
  6. Jmari K., Mironneau C., Mironneau J. Canaux calciques des cellules musculaires lisses. J Physiol (Paris) 1986;81(3):168–176. [PubMed] [Google Scholar]
  7. Jmari K., Mironneau C., Mironneau J. Inactivation of calcium channel current in rat uterine smooth muscle: evidence for calcium- and voltage-mediated mechanisms. J Physiol. 1986 Nov;380:111–126. doi: 10.1113/jphysiol.1986.sp016275. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kokubun S., Prod'hom B., Becker C., Porzig H., Reuter H. Studies on Ca channels in intact cardiac cells: voltage-dependent effects and cooperative interactions of dihydropyridine enantiomers. Mol Pharmacol. 1986 Dec;30(6):571–584. [PubMed] [Google Scholar]
  9. Lee H. R., Roeske W. R., Yamamura H. I. High affinity specific [3H](+)PN 200-110 binding to dihydropyridine receptors associated with calcium channels in rat cerebral cortex and heart. Life Sci. 1984 Aug 13;35(7):721–732. doi: 10.1016/0024-3205(84)90340-0. [DOI] [PubMed] [Google Scholar]
  10. Morel N., Godfraind T. Prolonged depolarization increases the pharmacological effect of dihydropyridines and their binding affinity for calcium channels of vascular smooth muscle. J Pharmacol Exp Ther. 1987 Nov;243(2):711–715. [PubMed] [Google Scholar]
  11. Munson P. J., Rodbard D. Ligand: a versatile computerized approach for characterization of ligand-binding systems. Anal Biochem. 1980 Sep 1;107(1):220–239. doi: 10.1016/0003-2697(80)90515-1. [DOI] [PubMed] [Google Scholar]
  12. Ohya Y., Kitamura K., Kuriyama H. Regulation of calcium current by intracellular calcium in smooth muscle cells of rabbit portal vein. Circ Res. 1988 Feb;62(2):375–383. doi: 10.1161/01.res.62.2.375. [DOI] [PubMed] [Google Scholar]
  13. Sarmiento J. G., Janis R. A., Katz A. M., Triggle D. J. Comparison of high affinity binding of calcium channel blocking drugs to vascular smooth muscle and cardiac sarcolemmal membranes. Biochem Pharmacol. 1984 Oct 15;33(20):3119–3123. doi: 10.1016/0006-2952(84)90066-2. [DOI] [PubMed] [Google Scholar]
  14. 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]
  15. Weiland G. A., Molinoff P. B. Quantitative analysis of drug-receptor interactions: I. Determination of kinetic and equilibrium properties. Life Sci. 1981 Jul 27;29(4):313–330. doi: 10.1016/0024-3205(81)90324-6. [DOI] [PubMed] [Google Scholar]

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