Abstract
1. In intact BC3H1 cells the EC50 of noradrenaline (NA) for the inositol phosphate response measured at 37 degrees C (EC50 = 193 nM) was much lower than its apparent dissociation constant (Ki37 degrees C = 83.211 microM) determined at this temperature by [3H]-prazosin binding. 2. After pretreatment of the cells with NA at 37 degrees C for 45 min, the time used in binding assays at this temperature, this difference between EC50 and Ki37 degrees C did not decrease significantly. An agonist-induced reduction in alpha 1-adrenoceptor affinity can therefore not explain the very high Ki37 degrees C value. 3. NA pretreatment at 37 degrees C decreased the number of [3H]-prazosin binding sites (assessed by whole cell binding at 2 degrees C) by only 49%; not by 100%, the value expected if agonist-induced receptor internalization were the origin of the very low Ki37 degrees C. 4. The EC50 of NA for the inositol phosphate response in the presence of 156 pM [3H]-prazosin was 1.841 microM but the IC50 of NA for the inhibition of [3H]-prazosin binding (126 pM) was 316 microM. As there is no alpha 1-adrenoceptor reserve in these cells we propose that at 37 degrees C [3H]-prazosin interacts, not only with the catecholamine recognition site (site 1) of the receptor, but also reacts weakly with another site from which it cannot be directly displaced by catecholamine-like substances (site 2).
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Selected References
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- Amitai G., Brown R. D., Taylor P. The relationship between alpha 1-adrenergic receptor occupation and the mobilization of intracellular calcium. J Biol Chem. 1984 Oct 25;259(20):12519–12527. [PubMed] [Google Scholar]
- Bar-Sinai A., Aldouby Y., Chorev M., Levitzki A. Association of turkey erythrocyte beta-adrenoceptors with a specific lipid component. EMBO J. 1986 Jun;5(6):1175–1180. doi: 10.1002/j.1460-2075.1986.tb04343.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berridge M. J., Downes C. P., Hanley M. R. Lithium amplifies agonist-dependent phosphatidylinositol responses in brain and salivary glands. Biochem J. 1982 Sep 15;206(3):587–595. doi: 10.1042/bj2060587. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bone E. A., Fretten P., Palmer S., Kirk C. J., Michell R. H. Rapid accumulation of inositol phosphates in isolated rat superior cervical sympathetic ganglia exposed to V1-vasopressin and muscarinic cholinergic stimuli. Biochem J. 1984 Aug 1;221(3):803–811. doi: 10.1042/bj2210803. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Cornett L. E., Ball D. W., Norris J. S. alpha 1-Adrenergic receptors of a smooth muscle cell line: guanine nucleotides do not regulate agonist affinities. J Recept Res. 1981;2(5-6):601–615. doi: 10.3109/107998981809038887. [DOI] [PubMed] [Google Scholar]
- Cornett L. E., Norris J. S. Characterization of the alpha 1-adrenergic receptor subtype in a smooth muscle cell line. J Biol Chem. 1982 Jan 25;257(2):694–697. [PubMed] [Google Scholar]
- Corvera S., Schwarz K. R., Graham R. M., García-Sáinz J. A. Phorbol esters inhibit alpha 1-adrenergic effects and decrease the affinity of liver cell alpha 1-adrenergic receptors for (-)-epinephrine. J Biol Chem. 1986 Jan 15;261(2):520–526. [PubMed] [Google Scholar]
- Dixon R. A., Sigal I. S., Candelore M. R., Register R. B., Scattergood W., Rands E., Strader C. D. Structural features required for ligand binding to the beta-adrenergic receptor. EMBO J. 1987 Nov;6(11):3269–3275. doi: 10.1002/j.1460-2075.1987.tb02645.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dixon R. A., Sigal I. S., Rands E., Register R. B., Candelore M. R., Blake A. D., Strader C. D. Ligand binding to the beta-adrenergic receptor involves its rhodopsin-like core. Nature. 1987 Mar 5;326(6108):73–77. doi: 10.1038/326073a0. [DOI] [PubMed] [Google Scholar]
- Dohlman H. G., Caron M. G., Strader C. D., Amlaiky N., Lefkowitz R. J. Identification and sequence of a binding site peptide of the beta 2-adrenergic receptor. Biochemistry. 1988 Mar 22;27(6):1813–1817. doi: 10.1021/bi00406a002. [DOI] [PubMed] [Google Scholar]
- Fratelli M., De Blasi A. Agonist-induced alpha 1-adrenergic receptor changes. Evidence for receptor sequestration. FEBS Lett. 1987 Feb 9;212(1):149–153. doi: 10.1016/0014-5793(87)81575-2. [DOI] [PubMed] [Google Scholar]
- Fratelli M., Marasco O., De Blasi A. Two subpopulations of alpha 1-adrenergic receptors with high and low affinity for agonists: short-term exposure to agonists reduced the high-affinity sites. Biochim Biophys Acta. 1987 Aug 19;930(1):87–96. doi: 10.1016/0167-4889(87)90159-5. [DOI] [PubMed] [Google Scholar]
- Goldstein J. L., Anderson R. G., Brown M. S. Coated pits, coated vesicles, and receptor-mediated endocytosis. Nature. 1979 Jun 21;279(5715):679–685. doi: 10.1038/279679a0. [DOI] [PubMed] [Google Scholar]
- Hertel C., Perkins J. P. Receptor-specific mechanisms of desensitization of beta-adrenergic receptor function. Mol Cell Endocrinol. 1984 Oct;37(3):245–256. doi: 10.1016/0303-7207(84)90094-7. [DOI] [PubMed] [Google Scholar]
- Hoyer D. Characterization of IBE 2254 binding to alpha 1-adrenergic receptors on intact DDT1 smooth muscle cells: comparison with membrane binding and correlation with phosphoinositides breakdown. J Recept Res. 1984;4(1-6):51–67. doi: 10.3109/10799898409042539. [DOI] [PubMed] [Google Scholar]
- Hughes R. J., Insel P. A. Agonist-mediated regulation of alpha 1- and beta 2-adrenergic receptor metabolism in a muscle cell line, BC3H-1. Mol Pharmacol. 1986 Jun;29(6):521–530. [PubMed] [Google Scholar]
- Kendall D. A., Brown E., Nahorski S. R. Alpha 1-adrenoceptor-mediated inositol phospholipid hydrolysis in rat cerebral cortex: relationship between receptor occupancy and response and effects of denervation. Eur J Pharmacol. 1985 Aug 7;114(1):41–52. doi: 10.1016/0014-2999(85)90518-7. [DOI] [PubMed] [Google Scholar]
- Kobilka B. K., Kobilka T. S., Daniel K., Regan J. W., Caron M. G., Lefkowitz R. J. Chimeric alpha 2-,beta 2-adrenergic receptors: delineation of domains involved in effector coupling and ligand binding specificity. Science. 1988 Jun 3;240(4857):1310–1316. doi: 10.1126/science.2836950. [DOI] [PubMed] [Google Scholar]
- Leeb-Lundberg L. M., Cotecchia S., DeBlasi A., Caron M. G., Lefkowitz R. J. Regulation of adrenergic receptor function by phosphorylation. I. Agonist-promoted desensitization and phosphorylation of alpha 1-adrenergic receptors coupled to inositol phospholipid metabolism in DDT1 MF-2 smooth muscle cells. J Biol Chem. 1987 Mar 5;262(7):3098–3105. [PubMed] [Google Scholar]
- Leeb-Lundberg L. M., Cotecchia S., Lomasney J. W., DeBernardis J. F., Lefkowitz R. J., Caron M. G. Phorbol esters promote alpha 1-adrenergic receptor phosphorylation and receptor uncoupling from inositol phospholipid metabolism. Proc Natl Acad Sci U S A. 1985 Sep;82(17):5651–5655. doi: 10.1073/pnas.82.17.5651. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mauger J. P., Sladeczek F., Bockaert J. Characteristics and metabolism of alpha 1 adrenergic receptors in a nonfusing muscle cell line. J Biol Chem. 1982 Jan 25;257(2):875–879. [PubMed] [Google Scholar]
- Porzig H., Becker C., Reuter H. Competitive and non-competitive interactions between specific ligands and beta-adrenoceptors in living cardiac cells. Naunyn Schmiedebergs Arch Pharmacol. 1982 Nov;321(2):89–99. doi: 10.1007/BF00518474. [DOI] [PubMed] [Google Scholar]
- Schwarz K. R., Lanier S. M., Carter E. A., Graham R. M., Homcy C. J. Transient high-affinity binding of agonists to alpha 1-adrenergic receptors of intact liver cells. FEBS Lett. 1985 Aug 5;187(2):205–210. doi: 10.1016/0014-5793(85)81243-6. [DOI] [PubMed] [Google Scholar]
- Sibley D. R., Lefkowitz R. J. Molecular mechanisms of receptor desensitization using the beta-adrenergic receptor-coupled adenylate cyclase system as a model. Nature. 1985 Sep 12;317(6033):124–129. doi: 10.1038/317124a0. [DOI] [PubMed] [Google Scholar]
- Sladeczek F., Bockaert J., Mauger J. P. Differences between agonist and antagonist binding to alpha 1-adrenergic receptors of intact and broken-cell preparations. Mol Pharmacol. 1983 Nov;24(3):392–397. [PubMed] [Google Scholar]
- Sladeczek F., Schmidt B. H., Alonso R., Vian L., Tep A., Yasumoto T., Cory R. N., Bockaert J. New insights into maitotoxin action. Eur J Biochem. 1988 Jul 1;174(4):663–670. doi: 10.1111/j.1432-1033.1988.tb14149.x. [DOI] [PubMed] [Google Scholar]
- Sladeczek F., Schmidt B. H., Cory R. N., el Moatassim C., Alonso R., Kirk K. L., Kirk C. J., Rouot B., Bockaert J. Complex interactions of agonists with alpha 1-adrenoceptors in intact cells. Br J Pharmacol. 1988 Dec;95(4):1133–1140. doi: 10.1111/j.1476-5381.1988.tb11748.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Staehelin M., Simons P., Jaeggi K., Wigger N. CGP-12177. A hydrophilic beta-adrenergic receptor radioligand reveals high affinity binding of agonists to intact cells. J Biol Chem. 1983 Mar 25;258(6):3496–3502. [PubMed] [Google Scholar]
- Steinman R. M., Mellman I. S., Muller W. A., Cohn Z. A. Endocytosis and the recycling of plasma membrane. J Cell Biol. 1983 Jan;96(1):1–27. doi: 10.1083/jcb.96.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Toews M. L. Comparison of agonist-induced changes in beta- and alpha 1-adrenergic receptors of DDT1 MF-2 cells. Mol Pharmacol. 1987 Jan;31(1):58–68. [PubMed] [Google Scholar]
- Yarden Y., Rodriguez H., Wong S. K., Brandt D. R., May D. C., Burnier J., Harkins R. N., Chen E. Y., Ramachandran J., Ullrich A. The avian beta-adrenergic receptor: primary structure and membrane topology. Proc Natl Acad Sci U S A. 1986 Sep;83(18):6795–6799. doi: 10.1073/pnas.83.18.6795. [DOI] [PMC free article] [PubMed] [Google Scholar]
