Abstract
The behavioral effects of seven metabolically stable analogs of adenosine were studied in squirrel monkeys responding under a fixed-interval (FI) schedule of stimulus-shock termination. All drugs produced dose-related decreases in response rate, but differed in potency by up to three orders of magnitude. The 5′-carboxamine and 2-chlorine substituted analogs were more potent than the N6-substituted analogs. The potencies of the adenosine analogs in decreasing schedule-controlled behavior correlate well with their reported affinities for adenosine A2, but not A1, recognition sites as determined by displacement of bound ligands or modulation of adenylate cyclase activity. The results suggest that the behavioral effects of adenosine analogs in squirrel monkeys are linked to their actions at adenosine A2 receptors.
References
Barraco RA, Coffin VL, Altman HJ, Phillis JW (1983) Central effects of adenosine analogs on locomotor activity in mice and antagonism by caffeine. Brain Res 272:392–395
Bruns RF (1980) Adenosine receptor activation in human fibroblasts: nucleoside agonists and antagonists. Can J Physiol Pharmacol 58:673–691
Bruns RF, Lu GH, Pugsley TA (1986) Characterization of the A2 adenosine receptor labeled by [3H]NECA in rat striatal membranes. Mol Pharmacol 29:331–346
Coffin VL, Carney JM (1986) Effects of selected analogs of adenosine on schedule controlled behavior in rats. Neuropharmacology (in press)
Coffin VL, Spealman RD (1985) Modulation of the behavioral effects of chlordiazepoxide by methylxanthines and analogs of adenosine in squirrel monkeys. J Pharmacol Exp Ther 235:724–728
Daly JW (1982) Adenosine receptors: targets for future drugs. J Med Chem 25:197–207
Dunwiddie TV, Fredholm BB (1984) Adenosine receptors mediating inhibitory electrophysiological responses in rat hippocampus are different from receptors mediating cyclic AMP accumulation. Naunyn-Schmiedebergs Arch Pharmacol 326:294–301
Ebersolt C, Premont J, Prochiantz A, Perez M, Bockaert J (1983) Inhibition of brain adenylate cyclase by A1 adenosine receptors: pharmacological characteristics and locations. Brain Res 267:123–129
Geiger JD, LaBella FS, Nagy JI (1984) Characterization and localization of adenosine receptors in rat spinal cord. J Neurosci 4:2303–2310
Glowa JR, Spealman RD (1984) Behavioral effects of caffeine, N6-(l-phenylisopropyl) adenosine and their combination in the squirrel monkey. J Pharmacol Exp Ther 231:665–670
John D, Fox IH (1985) Characteristics of high-affinity and low-affinity adenosine binding sites in human cerebral cortex. J Lab Clin Med 106:401–407
Londos C, Cooper DMF, Wolff J (1980) Subclasses of adenosine receptors. Proc Natl Acad Sci 77:2251–2254
Schutz W, Steurer G, Tuisl E (1983) Evidence for Ra-site adenosine receptors in rat brain microvessels. In: Berne RM, Rall TW, Rubio R (eds) Regulatory function of adenosine. The Hague, Netherlands: Martinus Nighoff, p 540
Snyder SH (1985) Adenosine as a neuromodulator. Ann Rev Neurosci 8:103–124
Ukena D, Furler R, Lohse MJ, Engel G, Schwabe U (1984) Labelling of Ri adenosine receptors in rat fat cell membranes with (−)-[125iodo]N6-hydroxyphenylisopropyladenosine. Naunyn-Schmiedebergs Arch Pharmacol 326:233–240
Ukena D, Schirren CG, Klotz K-N, Schwabe U (1985) Evidence for an A2 adenosine receptor in guinea pig lung. Naunyn-Schmiedebergs Arch Pharmacol 331:89–95
Van Calker D, Muller M, Hamprecht B (1979) Adenosine regulates via two different types of receptors, the accumulation of cyclic AMP in cultured brain cells. J Neurochem 33:999–1005
Williams M, Abreu M, Noronha-Blob L (1986) Adenosine (Ado) receptors in the PC12 pheochromocytoma cell line: characterization by radioligand binding. Fed Proc 45:566
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Animals used in this study were maintained in accordance with the guidelines of the Committee on Animals of the Harvard Medical School and of the “Guide for Care and Use of Laboratory Animals” of the Institute of Laboratory Animal Resources, National Research Council, Department of Health, Education and Welfare, Publication No. (NIH)85-23, revised 1985
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Spealman, R.D., Coffin, V.L. Behavioral effects of adenosine analogs in squirrel monkeys: relation to adenosine A2 receptors. Psychopharmacology 90, 419–421 (1986). https://doi.org/10.1007/BF00179203
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DOI: https://doi.org/10.1007/BF00179203