Summary
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1.
Longitudinal muscle strips of the guineapig small intestine were incubated with Tyrode solution containing the choline analogue pyrrolidinecholine. At the end of the incubation the concentrations of acetylcholine and its analogue acetylpyrrolidinecholine were determined in the strips by gas chromatography.
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2.
After 120 min of incubation with 1 mM pyrrolidinecholine, acetylpyrrolidinecholine comprised about 15% of the total amount of acetylcholine plus acetylpyrrolidinecholine. Electrical stimulation (1 Hz) of the strips during the incubation slightly increased the proportion of acetylpyrrolidinecholine to 21%.
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3.
The acetylcholine content of control strips increased significantly during incubation in Tyrode solution. It is suggested that this increase results from the presence of large amounts of endogenous choline that were found in the medium and in the strips. Pyrrolidinecholine in concentrations between 1 and 10 mM inhibited the increased acetylcholine synthesis. The missing acetylcholine was fully replaced by acetylpyrrolidinecholine.
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4.
In denervated strips the formation of acetylpyrrolidinecholine was reduced to 21±5% of that of innervated strips. In both, denervated and innervated strips the amounts of acetylpyrrolidinecholine were significantly correlated to the acetylcholine contents. This indicates that acetylpyrrolidinecholine is synthesized at the same site as acetylcholine, i.e. in the myenteric plexus attached to the strips.
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5.
Electrical stimulation (10 Hz; 1 ms; 5 min) of the strips at the end of the incubation with pyrrolidinecholine caused an output of acetylcholine and acetylpyrrolidinecholine into the bath fluid. The release experiments were carried out in the presence of eserine. The release of acetylcholine was significantly diminished, but the false transmitter released fully balanced the decrease in acetylcholine release. The proportion of acetylpyrrolidinecholine to acetylcholine was higher in the medium than in the tissue indicating a preferential release of the false transmitter.
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References
Barker, L. A., Mittag, T. W.: Comparative studies of substrates and inhibitors of choline transport and choline acetyltransferase. J. Pharmacol. exp. Ther. 192, 86–94 (1975)
Cohen, E. L., Wurtman, R. J.: Brain acetylcholine: increase after systemic choline administration. Life Sci. 16, 1095–1102 (1975)
Collier, B., Barker, L. A., Mittag, T. W.: The release of acetylated choline analogues by a sympathetic ganglion. Molec. Pharmacol. 12, 340–344 (1976)
Ilson, D., Collier, B.: Triethylcholine as a precursor to a cholinergic false transmitter. Nature (Lond.) 254, 618–620 (1975)
Karlén, B., Lundgren, G., Nordgren, I., Holmstedt, B.: Ion-pair extraction and gas-phase analysis of acetylcholine and choline. In: Choline and acetylcholine: Handbook of chemical assay methods (I. Hanin, ed.), pp. 163–179. New York: Raven Press 1974
Kilbinger, H.: Gas chromatographic estimation of acetylcholine in the rabbit heart using a nitrogen selective detector. J. Neurochem. 21, 421–429 (1973)
Kilbinger, H., Lindmar, R., Löffelholz, K., Muscholl, E., Patil, P. N.: Storage and release of false transmitters after infusion of (+)-and (-)-α-methyldopamine. Naunyn-Schmiedebergs Arch. Pharmak. 271, 234–248 (1971)
Kilbinger, H., Wagner, P.: Inhibition by oxotremorine of acetylcholine resting release from guinea-pig ileum longitudinal muscle strips. Naunyn-Schmiedeberg's Arch. Pharmacol. 287, 47–60 (1975)
Kilbinger, H., Wagner, A., Zerban, R.: Some pharmacological properties of the false cholinergic transmitter acetylpyrrolidinecholine and its precursor pyrrolidinecholine. Naunyn-Schmiedeberg's Arch. Pharmacol. 295, 81–87 (1976)
Kopin, I. J.: False adrenergic transmitters. Ann. Rev. Pharmacol. 8, 377–394 (1968)
Molenaar, P. C., Polak, R. L.: Analysis of the preferential release of newly synthesized acetylcholine by cortical slices from rat brain with the aid of two different labelled precursors. J. Neurochem. 26, 95–99 (1976)
Muscholl, E.: Adrenergic false transmitters. Handbook exp. pharmacol. (H. Blaschko and E. Muscholl, eds.), Vol. 33, pp. 618–660, Berlin-Heidelberg-New York: Springer 1972
Paton, W. D. M., Vizi, E. S.: The inhibitory action of noradrenaline and adrenaline on acetylcholine output by guinea-pig ileum longitudinal muscle strip. Brit. J. Pharmacol. 35, 10–28 (1969)
Paton, W. D. M., Zar, M. A.: The origin of acetylcholine released from guinea-pig intestine and longitudinal muscle strips. J. Physiol. (Lond.) 194, 13–33 (1968)
Pert, C. B., Snyder, H. S.: High affinity transport of choline into the myenteric plexus of guinea-pig intestine. J. Pharmacol. exp. Ther. 191, 102–108 (1974)
Sachs, L.: Statistische Auswertungsmethoden, 2. Aufl. Berlin-Heidelberg-New York: Springer 1969
Zimmermann, H., Dowdall, M. J.: Synthesis, vesicular uptake and release of a cholinergic false transmitter. Abstr. 5th Int. Meet. int. Soc. Neurochem. Barcelona, p. 128 (1975)
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Kilbinger, H. Formation and release of acetylpyrrolidinecholine (N-methyl, N-acetoxyethylpyrrolidinium) as a false cholinergic transmitter in the myenteric plexus of the guinea-pig small intestine. Naunyn-Schmiedeberg's Arch. Pharmacol. 296, 153–158 (1977). https://doi.org/10.1007/BF00508468
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DOI: https://doi.org/10.1007/BF00508468