Summary
The compound 1,4-dihydro-2,6-dimethyl-4-(2-trifluoromethylphenyl)-3,5-pyridinecarboxylic acid 2-(amino-ethyl)ethylester was reacted with N-succinimidyl 3-(4-hydroxy, 5-125I-iodophenyl)propionate (2,200 Ci/mmol. The purified, 125I-labelled product of this reaction is termed 125I-iodipine and has a specific activity of ∼2,200 Ci/mmol on the date of preparation. 125I-Iodipine binds reversibly in a saturable manner and with high affinity to skeletal muscle and brain membranes with K D values at 25° C of 400 and 60 pmol/l, respectively. The binding of 125I-iodipine is stereoselectively inhibited by chiral 1,4-dihydropyridine calcium channel blockers. 125I-Iodipine labelled sites also recognize the recently described 1,4-dihydropyridine calcium channel activators and discriminate the chemically unrelated compounds (−)- and (+)verapamil, (−)- and (+)methoxyverapamil and d- and l-cis diltiazem. It is concluded that 125I-iodipine labels the putative calcium channel.
This is a preview of subscription content, log in via an institution to check access.
References
Albus U, Habermann E, Ferry DR, Glossmann H (1984) Novel 1,4-dihydropyridine (Bay K 8644) facilitates calcium dependent 3H-noradrenaline release from PC 12 cells. J Neurochem (in press)
Bellemann P, Ferry D, Lübbecke F, Glossmann H (1981) 3H-Nitrendipine, a potent calcium antagonist binds with high affinity to cardiac membranes. Arzneimittelforsch 31:2064–2067
Bolander FF Jr, Fellows RE (1975) Growth hormone covalently bound to sepharose or glass. Analysis of ligand release rates and characterization of soluble radiolabelled products. Biochemistry 14:2938–2943
DeLean A, Munson PJ, Rodbard D (1978) Simultaneous analysis of families of sigmoid curves: application to bioassay, radioligand assay and physiological dose-response curves. Am J Physiol 4:E97-E102
Eglen RM, Fraser S, Patmore L, Whiting RL (1983) Comparative effects of nicardipine and nifedipine on coronary artery, mesenteric artery and portal vein. Br J Pharmacol 80:556P
Ferry DR, Glossmann H (1982a) Identification of putative calcium channels in skeletal muscle microsomes. FEBS Lett 148:331–337
Ferry DR, Glossmann H (1982b) Evidence for multiple drug receptor sites within the putative calcium channel. Naunyn-Schmiedeberg's Arch Pharmacol 321:80–83
Ferry DR, Goll A, Glossmann H (1983) Differential labelling of putative skeletal muscle calcium channels by 3H-nifedipine, 3H-nitrendipine, 3H-nimodipine and 3H-PN 200-110. Naunyn-Schmiedeberg's Arch Pharmacol 323:276–277
Fosset M, Jaimovich E, Delpont E, Lazdunski M (1983) 3H-Nitrendipine labelling of the Ca2+ channel in skeletal muscle. Eur J Pharmacol 86:141–142
Glossmann H, Ferry DR (1983) Molecular approach to the calcium channel. Drug Dev 9:63–98
Glossmann H, Lübbecke F (1982) 125I-HEAT: Fifty percent of the ligand can bind to the alpha1-adrenoceptors with extremely high affinity. Naunyn-Schmiedeberg's Arch Pharmacol 321:7–10
Glossmann H, Ferry DR, Lübbecke F, Mewes R, Hofmann F (1982) Calcium channels: direct identification with radioligand binding studies. TIPS 3:431–437
Glossmann H, Linn T, Rombusch M, Ferry DR (1983) Temperature-dependent regulation of d-cis-diltiazem binding to Ca2+ channels by 1,4-dihydropyridine channel agonists and antagonists. FEBS Lett 160:226–232
Goll A, Ferry DR, Glossmann H (1983) Target size analysis of skeletal muscle Ca2+ channels. FEBS Lett 157:63–69
Holck M, Thorens S, Haeusler G (1982) Characterisation of 3H-nifedipine binding sites in rabbit myocardium. Eur J Pharmacol 85:305–315
Hulthén UL, Landmann R, Bürgisser E, Bühler FR (1982) Highaffinity binding sites for 3H-verapamil in cardiac membranes. J Cardiovasc Pharmacol 4:S 291-S 293
Janis RA, Triggle DJ (1983) New developments in Ca2+ channel antagonists. J Med Chem 26:775–785
Janis RA, Maurer SC, Sarmieoto JC, Bolger GT, Triggle DJ (1982) Binding of 3H-nimodipine to cardiac and smooth muscle membranes. Eur J Pharmacol 82:191–194
Schramm M, Thomas G, Towart R, Franckowiak G (1983) Novel dihydropyridines with positive inotropic action through activation of Ca2+ channels. Nature 307:535–537
Towart R, Wehinger E, Meyer H (1981) Effects of unsymmetrical ester substituted 1,4-dihydropyridine derivatives and their optical isomers on contraction of smooth muscle. Naunyn-Schmiedeberg's Arch Pharmacol 317:183–185
Truog AG, Brunner H, Criscione T, Fallert M, Kühnis H, Meier M, Rogg H (1984) CGP 28392, a dihydropyridine Ca2+ entry stimulator In: Rubin RP, Weiss GB, Putney JW Jr (eds) Calcium in biological systems. Plenum Press, New York (in press)
Author information
Authors and Affiliations
Additional information
Patent applied for
This is part of the thesis of D. R. Ferry
Rights and permissions
About this article
Cite this article
Ferry, D.R., Glossmann, H. 125I-iodipine*, a new high affinity ligand for the putative calcium channel. Naunyn-Schmiedeberg's Arch. Pharmacol. 325, 186–189 (1984). https://doi.org/10.1007/BF00506200
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00506200