Abstract
The release of acetylcholine (ACh) from brain tissue is known to be inhibited by muscarinic autoreceptors on cholinergic nerve terminals but the mechanism of the inhibition is not understood. Atropine brings about an increase of ACh release by removing the inhibitory action of autoreceptors. We investigated whether the effect of atropine on the release of [14C]ACh newly synthesized during incubations from [U-14C] glucose depends on the concentration of Ca2+ in the medium. In rat striatal slices incubated in the presence of an inhibitor of cholinesterases and of 30 mmol/l K+, significant increases in the release of [14C]ACh elicited by atropine were only observed during incubations with very low concentrations of Ca2+. This finding supports the view that the activation of presynaptic muscarinic autoreceptors in the brain affects the release of ACh by reducing the availability of Ca2+ that is required for transmitter liberation.
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References
MacInfosh, F. C., and Oborin, P. E. 1953. Release of acetylcholine from intact cerebral cortex. Pages 580–581,in Abstracts of the XIX International Physiological Congress.
Michaelson, D. M., McDowall, G., and Sarne, Y. 1984. Opiates inhibit acetylcholine release from Torpedo nerve terminals by blocking Ca2+ influx. J. Neurochem. 43:614–618.
Szerb, J. C. 1964. The effect of tertiary and quaternary atropine on cortical acetylcholine output and on the electroencephalogram in cats. Can. J. Physiol. Pharmacol. 42:303–314.
Polak, R. L. 1965. Effect of hyoscine on the output of acetylcholine into perfused cerebral ventricles of cats. J. Physiol. 181:317–323.
Polak, R. L., and Meeuws, M. M. 1966. The influence of atropine on the release and uptake of acetylcholine by the isolated cerebral cortex of the rat. Biochem. Pharmacol. 15:989–992.
Bartolini, A., and Pepeu, G. 1967. Investigations into the acetylcholine output from the cerebral cortex of the cat in the presence of hyoscine. Br. J. Pharmacol. Chemother. 31:66–73.
Marchi, M., Paudice, P., and Raiteri, M. 1981. Autoregulation of acetylcholine release in isolated hippocampal nerve endings. Eur. J. Pharmacol. 73:75–79.
Molenar P. C., and Polak, R. L. 1980. Inhibition of acetylcholine release by activation of acetycholine receptors. Progr. Pharmacol. 3/4:39–44.
Kilbinger, H. 1984. Presynaptic muscarine receptors modulating acetylcholine release. Trends Pharmacol. Sci. 5:103–105.
Illes, P. 1986. Mechanisms of receptor-mediated modulation of transmitter release in noradrenergic, cholinergic and sensory neurones. Neuroscience 17:909–928.
Alberts, P., and Stjärne, L. 1982. Role of calcium in muscarinic autoinhibition of3H-acetylcholine secretion in guinea-pig ileum myenteric plexus. Acta Physiol. Scand. 115:487–491.
Onge, E. S., Otero, D. A., Bottiglieri, D. F., and Meyer, E. M. 1986. Effects of different secretagogues and intracellular messengers on the muscarinic modulation of [3H]acetylcholine release. Neurochem. Res. 11:1547–1556.
Wessler, I., Eschenbruch, V., Halim, S., and Kilbinger, H., 1987. Presynaptic effects of scopolamine, oxotremorine, noradrenaline and morphine on [3H]acetylcholine release from the myenteric plexus at different stimulation frequencies and calcium concentrations. Naunyn-Schmiedeberg's Arch. Pharmacol. 335:597–604.
Molenaar, P. C., and Polak, R. L. 1970. Stimulation by atropine of acetylcholine release and synthesis in cortical slices from rat brain. Brit. J. Pharmacol. 40:406–417.
Doležal, V., and Tuček, S. 1982. Effects of choline and glucose on atropine-induced alterations of acetylcholine synthesis and content in the caudate nuclei of rats. Brain Res. 140:285–293.
McIlwain, H., and Rodnight, R. 1962. Practical Neurochemistry. Pages 126–129, Churchill, London.
Braggaar-Schaap, P. A. 1979. A sensitive method for assaying acetylcholine synthesis in human and frog skeletal muscle. J. Neurochem. 33:389–392.
James, M. K., and Cubeddu, L. X. 1984. Frequency-dependent muscarinic receptor modulation of acetylcholine and dopamine release from rabbit striatum. J. Pharmacol. Exp. Ther. 229:98–104.
Sawynok, J., and Jhamandas, K. 1979. Interactions of methylxanthines, nonxantine phosphodiesterase inhibitors, and calcium with morphine in the guinea-pig myenteric plexus. Can. J. Physiol. Pharmacol. 57:853–859.
Michaelson, D. M., McDowall, G., and Sarne, Y. 1984. Opiates inhibit acetylcholine from Torpedo nerve terminals by blocking Ca2+ influx. J. Neurochem. 43:614–618.
Araujo, D. M., and Collier, B. 1987. Do presynaptic opiate receptors and α-adrenoreceptors alter acetylcholine release from a sympathetic ganglion by a similar mechanism. Eur. J. Pharmacol. 139:179–186.
Dubey, M. P., Muscholl, E., and Pfcifer, A. 1975. Muscarinic inhibition of potassium-induced noradrenaline release and its dependence on the calcium concentration. Naunyn-Schmiedeberg's Arch. Pharmacol. 291:1–15.
Rospars, J. P., Lefresne, P., Beaujouan, J. C., and Glowinski, J. 1977. Effect of external ACh and of atropine on14C-ACh synthesis and release in rat cortical slices. Naunyn-Schmiedeberg's Arch. Pharmacol. 300:153–161.
Luz, S., Pinchasi, I., and Michaelson, D. M. 1983. Differential inhibition of the release of endogenous and newly synthesized acetylcholine from Torpedo synaptosomes by presynaptic muscarinic receptors. FEBS Lett. 164:9–12.
Doležal, V. and Tuček S. 1983. The effects of 4-aminopyridine and tetrodotoxin on the release of acetylcholine from rat striatal slices. Nauyn-Schmiedeberg's Arch. Pharmacol. 323:90–95.
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Doležal, V., Tuček, S. Effects of atropine on the release of newly synthesized acetylcholine from rat striatal slices at various concentrations of calcium ions. Neurochem Res 15, 41–45 (1990). https://doi.org/10.1007/BF00969182
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DOI: https://doi.org/10.1007/BF00969182