Summary
Radiation inactivation of alpha1-adrenoceptors in rat cerebral cortex membranes has been performed with 10 MeV electrons from a linear accelerator at temperatures ≤−100°C. Alpha1-adrenoceptor inactivation was monitored with [3H]-prazosin and ([125I]-2-(β-4-hydroxylphenyl)ethylaminomethyl)tetralone ([125I]-HEAT). Saturation analysis of irradiated membranes with both ligands indicated that a decrease in alpha-adrenoceptor density occurred with increasing radiation dose. The dissociation constants of [3H]-prazosin and [125I]-HEAT were not markedly changed by the irradiation. Application of the target volume theory gave molecular weights of 91,500±1,700 (S.D.) (D37: 19,6±0.36 Mrad) with [125I]-HEAT as ligand, and 77,000±18,000 (S.D.) (D37: 23.3±4.6 Mrad) with [3H]-prazosin, respectively, when an empirical temperature correction factor of 2.8 was used. [3H]-flunitrazepam-labelled benzodiazepine receptor target size was used as an internal control. The molecular weight of the alpha1-adrenoceptors, corrected for this internal control, was 85,000±1.600 ([125I]-HEAT) and 71,500±17,000 ([3H]-prazosin).
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References
Chang LR, Barnard EA, Lo MMS, Dolly JO (1981) Molecular sizes of benzodiazepine receptors and the interacting GABA receptors in the membrane. FEBS Lett 126:309–312
Doble A, Iversen LL (1982) Molecular size of benzodiazepine receptor in rat brain in situ: evidence for a functional dimer? Nature 295:522–523
Engel G, Hoyer D (1981) [125I] BE 2254, a new high affinity radioligand for alpha1-adrenoceptors. Eur J Pharmacol 73:221–224
Exton JH (1981) Molecular mechanisms involved in alpha-adrenergic responses. Mol Cell Endocrinol 23:233–264
Glossmann H, Presek P (1979) Alpha noradrenergic receptors in brain membranes: sodium, magnesium and guanyl nucleotides modulate agonist binding. Naunyn-Schmiedeberg's Arch Pharmacol 306:67–73
Glossmann H, Lübbecke F, Bellemann P, Presek P (1981a) Cation sensitivity of [125I]-HEAT binding to alpha1-adrenoceptors in rat cerebral cortex membranes. Eur J Pharmacol 75:149–153
Glossmann H, Lübbecke F, Bellemann P (1981b) [125I]-HEAT, a selective, high-affinity, high specific activity ligand for alpha-adrenoceptors. Naunyn-Schmiedeberg's Arch Pharmacol 318:1–9
Glossmann H, Lübbecke F, Bellemann P, Sattler E-L, Doell G (1982) Tonic modulation of alpha1-adrenoceptors. J Cardiovasc Pharmacol 4:51–57
Guellaen G, Aggerbeck M, Hanoune J (1979) Characterisation and solubilization of the α-adrenoceptor of rat liver plasma membranes labeled with [3H] phenoxybenzamine. J Biol Chem 254:10761–10768
Guellaen G, Goodhardt M, Hanoune J (1982) Recent advances in the purification of the alpha1-adrenoceptor. J Cardiovasc Pharmacol 4:530–534
Harmon JT, Kahn CR, Kempner ES, Schlegel W (1980) Characterisation of the insulin receptor in its membrane environment by radiation inactivation. J Biol Chem 255:3412–3419
Harmon JT, Kempner ES, Kahn CR (1981) Demonstration by radiation inactivation that insulin alters the structure of the insulin receptor in rat liver membranes. J Biol Chem 256:7719–7722
Hoffmann BB, Lefkowitz RJ (1980) Radioligand binding studies of adrenergic receptors. Ann Rev Pharmacol Toxicol 20:581–608
Hornung R, Presek P, Glossmann H (1979) Alpha-adrenoceptors in rat brain: Direct identification with prazosin. Naunyn-Schmiedeberg's Arch Pharmacol 308:223–230
Houslay MD, Ellory JC, Smith GA, Hesketh TR, Stein JM, Warren GB, Metcalfe JC (1979) Exchange of partners in glucagon receptor-adenylate cyclase complexes. Biochim Biophys Acta 467:208–219
Kempner ES, Schlegel W (1979) Size determination of enzymes by radiation inactivation. Analyt Biochem 92:2–10
Kempner ES, Miller JH, Schlegel W, Hearon JZ (1980) The functional unit of polyenzymes. J Biol Chem 255:6826–6831
Kepner GR, Macey RI (1968) Membrane enzyme systems molecular size determinations by radiation inactivation. Biochim Biophys Acta 163:188–203
Langer SZ (1974) Presynaptic regulation of catecholamine release. Biochem Pharmacol 23:1793–1800
Lo MMS, Barnard EA, Dolly JO (1982) Size of acetylcholine receptors in the membrane. An improved version of the radiation inactivation method. Biochemistry 21:2210–2217
Martini C, Lucacchini A, Ronka G, Hrelia S (1982) Isolation of putative benzodiazepine receptors from rat brain membranes by affinity chromatography. J Neurochem 38:15–19
Nielsen TB, Lad PM, Preston MS, Kempner E, Schlegel W, Rodbell M (1981) Structure of the turkey erythrocyte adenylate cyclase system. Proc Natl Acad Sci USA 78:722–726
Paul SM, Kempner ES, Skolnick P (1981) In situ molecular weight determination of brain and peripheral benzodiazepine binding sites. Eur J Pharmacol 76:465–466
Rodbell M (1980) The role of hormone receptors and GTP-regulating proteins in membrane transduction. Nature 284:17–22
Schlegel W, Kempner ES, Rodbell M (1979) Activation of adenylate cyclase in hepatic membranes involves interaction of the catalytic unit with multimeric complexes of regulatory proteins. J Biol Chem 254:5168–5176
Sieghart W, Karobath M (1980) Molecular heterogeneity of benzodiazepine receptors. Nature 286:285–287
Sieghart W, Moehler H (1982) Clonazepam like [3H]-flunitrazepam, is a photoaffinity label for the central type of benzodiazepine receptors. Eur J Pharmacol 81:171–173
Starke K (1972) Alpha sympathomimetic inhibition of adrenergic and cholinergic transmission in the rabbit heart. Naunyn-Schmiedeberg's Arch Pharmacol 274:18–45
Starke K (1981) Alpha-adrenoceptor subclassification. Rev Physiol Biochem Pharmacol 88:199–236
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Lübbecke, F., Ferry, D.R., Glossmann, H. et al. Radiation inactivation of alpha1-adrenoceptors. Naunyn-Schmiedeberg's Arch. Pharmacol. 323, 96–100 (1983). https://doi.org/10.1007/BF00634255
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DOI: https://doi.org/10.1007/BF00634255