Summary
Pig brain cortex synaptosomes and slices preincubated with 3H-5-hydroxytryptamine (3H-5-HT) were superfused with physiological salt solution containing citalopram (an inhibitor of 5-HT uptake), and the effects of indolethylamines and 5-HT receptor antagonists on the potassium- or electrically evoked 3H overflow were determine. The potassium (25 mmol/l)-evoked tritium overflow from cortex synaptosomes was inhibited by 5-HT; the inhibitory effect of 5-HT was counteracted by metitepine, which, by itself, did not affect the evoked overflow. 5-Methoxytryptamine (examined in the absence of citalopram) also produced an inhibition of the evoked overflow. In cortex slices, the electrically (3 Hz) evoked overflow was inhibited by 5-HT and 5-carboxamidotryptamine. The inhibitory effect of 5-HT was antagonized by metitepine, which, given alone, increased the evoked overflow, but was not attenuated by ketanserin and ICS 205-930 ([3α-tropanyl]-1H-indole-3-carboxylic acid ester), which, by themselves, did not influence the evoked overflow. The present results suggest that the serotoninergic nerve fibres of the pig brain cortex are endowed with presynaptic 5-HT1 receptors, which can be activated by endogenous and exogenous 5-HT.
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Bonanno G, Raiteri M (1987) Interactions between 5-HT uptake inhibition and activation of 5-HT autoreceptors by exogenous agonists in rat cerebral cortex slices and synaptosomes. Naunyn-Schmiedeberg's Arch Pharmacol 335:219–225
Bradley PB, Engel G, Feniuk W, Fozard JR, Humphrey PPA, Middlemiss DN, Mylecharane EJ, Richardson BP, Saxena PR (1986) Proposals for the classification and nomenclature of functional receptors for 5-hydroxytryptamine. Neuropharmacology 25:563–576
Engel G, Göthert M, Hoyer D, Schlicker E, Hillenbrand K (1986) Identity of inhibitory presynaptic 5-hydroxytryptamine (5-HT) autoreceptors in the rat brain cortex with 5-HT1B binding sites. Naunyn-Schmiedeberg's Arch Pharmacol 332:1–7
Feuerstein TJ, Lupp A, Hertting G (1987) The serotonin (5-HT) autoreceptor in the hippocampus of the rabbit: role of 5-HT biophase concentration. Neuropharmacology 26:1071–1080
Fink K, Betz R (1988) Presynaptic serotonin (5-HT) autoreceptors in the pig brain cortex. Naunyn-Schmiedeberg's Arch Pharmacol 337:R103
Galzin AM, Moret C, Verzier B, Langer SZ (1985) Interaction between tricyclic and nontricyclic 5-hydroxytryptamine uptake inhibitors and the presynaptic 5-hydroxytryptamine inhibitory autoreceptors in the rat hypothalamus. J Pharmacol Exp Ther 235:200–211
Göthert M (1985) Role of autoreceptors in the function of the peripheral and central nervous system. Arzneimittelforschung/Drug Res 35:1909–1916
Göthert M (1987) Inhibitory actions of serotonin (5-HT) on peripheral and central neurons. In: Rand MJ, Raper C (eds) Pharmacology. Elsevier Science Publishers, Amsterdam, pp 289–293
Göthert M, Huth H (1980) Alpha-adrenoceptor-mediated modulation of 5-hydroxytryptamine release from rat brain cortex slices. Naunyn-Schmiedeberg's Arch Pharmacol 313:21–26
Göthert M, Schlicker E (1987) Classification of serotonin receptors. J Cardiovasc Pharmacol 10 (Suppl 3) S3-S7
Heuring RE, Schlegel IR, Peroutka SJ (1986) Species variations in RU 24969 interactions with non-5-HT1A binding sites. Eur J Pharmacol 122:279–282
Heuring RE, Peroutka SJ (1987) Characterization of a novel 3H-5hydroxytryptamine binding site subtype in bovine brain membranes. J Neurosci 7:894–903
Hoyer D, Engel G, Kalkman HO (1985) Molecular pharmacology of 5-HT1 and 5-HT2 recognition sites in rat and pig brain membranes: radioligand binding studies with [3H]5-HT, [3H]8-OH-DPAT, (−)[125I]iodocyanopindolol, [3H]mesulergine and [3H]ketanserin. Eur J Pharmacol 118:13–23
Hoyer D, Pazos A, Probst A, Palacios JM (1986a) Serotonin receptors in the human brain. I. Characterization and autoradiographic localization of 5-HT1A recognition sites. Apparent absence of 5-HT1B recognition sites. Brain Res 376:85–96
Hoyer D, Pazos A, Probst A, Palacios JM (1986b) Serotonin receptors in the human brain. II. Characterization and autoradiographic localization of 5-HT1C and 5-HT2 recognition sites. Brain Res 376:97–107
Hoyer D, Waeber C, Palacios JM (1987) Identification of a 5-HT1 recognition site in pig and human brain different from 5-HT1A, 5-HT1B and 5-HT1C. Brit J Pharmacol 92:561 P
Limberger N, Bonanno G, Späth L, Starke K (1986) Autoreceptors and α2-adrenoceptors at the serotonergic axons of rabbit brain cortex. Naunyn-Schmiedeberg's ArchPharmacol 332:324–331
Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275
Middlemiss DN (1984) 8-Hydroxy-2-(di-n-propylamino)tetralin is devoid of activity at the 5-hydroxytryptamine autoreceptor in rat brain. Implications for the proposed link between the autoreceptor and the [3H] 5-HT recognition site. Naunyn-Schmiedeberg's Arch Pharmacol 327:18–22
Middlemiss DN, Bremer ME (1987) The terminal 5-HT autoreceptor in the guinea-pig frontal cortex: a pharmacological analysis. Brit J Pharmacol 92: 559 P
Moret C (1985) Pharmacology of the serotonin autoreceptor. In: Green AR (ed) Neuropharmacology of serotonin. Oxford University Press, Oxford New York Toronto Melbourne, pp 21–49
Mulder AH, van den Berg WB, Stoof JC (1975) Calcium-dependent release of radiolabeled catecholamines and serotonin from rat brain synaptosomes in a superfusion system. Brain Res 99: 419–424
Pazos A, Probst A, Palacios JM (1987) Serotonin receptors in the human brain. III. Autoradiographic mapping of serotonin-1 receptors. Neuroscience 21:97–122
Schlicker E, Brandt F, Classen K, Göthert M (1985) Serotonin release in human cerebral cortex and its modulation via serotonin receptors. Brain Res 331:337–341
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Fink, K., Schlicker, E., Betz, R. et al. Identification of presynaptic 5-HT1 autoreceptors in pig brain cortex synaptosomes and slices. Naunyn-Schmiedeberg's Arch Pharmacol 338, 14–18 (1988). https://doi.org/10.1007/BF00168806
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DOI: https://doi.org/10.1007/BF00168806