Abstract
1. The curare-like action of 2,2',2''-tripyridine (a synthetic by-product of the herbicide, paraquat) was studied in mouse phrenic nerve-diaphragm preparation. The inhibition by 2,2',2''-tripyridine of nerve-evoked twitches was dependent on the concentration, ranging from 1 to 100 microM, which had no significant effect on the twitch amplitudes evoked by direct muscle stimulation. 2. The twitch inhibition by 2,2',2''-tripyridine was reversible and could be antagonized by anticholinesterase agents such as neostigmine, physostigmine as well as ecothiophate. 3. Pretreatment with either 0.7 microM (+)-tubocurarine or 2.2 microM succinylcholine shifted the concentration-inhibition curve of 2,2',2''-tripyridine to the left. 4. 2,2'2''-Tripyridine inhibited not only acetylcholine-induced contracture of the denervated mouse diaphragm but also that of the chick biventer cervicis muscle. Like (+)-tubocurarine, 2,2',2''-tripyridine protected the twitches from the inhibition by alpha-bungarotoxin and also specifically inhibited the binding of [125I]-alpha-bungarotoxin to the mouse diaphragm. All of these findings indicate that 2,2',2''-tripyridine possesses curare-like action and inhibits the muscle contractions through binding to postsynaptic acetylcholine receptors. 5. The postsynaptic inhibition exhibited by 2,2',2''-tripyridine was also implicated in the tetanic fade, a decrease in the amplitude of miniature endplate potential (m.e.p.p.) and endplate potential (e.p.p.). 6. The clinical implication of these findings is that 2,2',2''-tripyridine may be involved in the cause of respiratory failure in paraquat-intoxicated workers since 2,2',2''-tripyridine is a by-product of paraquat synthesis.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bowman W. C. Prejunctional and postjunctional cholinoceptors at the neuromuscular junction. Anesth Analg. 1980 Dec;59(12):935–943. [PubMed] [Google Scholar]
- Chang C. C., Hong S. J. A regenerating release of acetylcholine from mouse motor nerve terminals treated with anticholinesterase agents. Neurosci Lett. 1986 Aug 29;69(2):203–207. doi: 10.1016/0304-3940(86)90604-x. [DOI] [PubMed] [Google Scholar]
- DAVIS B. J. DISC ELECTROPHORESIS. II. METHOD AND APPLICATION TO HUMAN SERUM PROTEINS. Ann N Y Acad Sci. 1964 Dec 28;121:404–427. doi: 10.1111/j.1749-6632.1964.tb14213.x. [DOI] [PubMed] [Google Scholar]
- FATT P., KATZ B. An analysis of the end-plate potential recorded with an intracellular electrode. J Physiol. 1951 Nov 28;115(3):320–370. doi: 10.1113/jphysiol.1951.sp004675. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GINSBORG B. L., WARRINER J. The isolated chick biventer cervicis nerve-muscle preparation. Br J Pharmacol Chemother. 1960 Sep;15:410–411. doi: 10.1111/j.1476-5381.1960.tb01264.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Howe-Grant M., Wu K. C., Bauer W. R., Lippard S. J. Binding of platinum and palladium metallointercalation reagents and antitumor drugs to closed and open DNAs. Biochemistry. 1976 Sep 21;15(19):4339–4346. doi: 10.1021/bi00664a031. [DOI] [PubMed] [Google Scholar]
- Jennette K. W., Lippard S. J., Vassiliades G. A., Bauer W. R. Metallointercalation reagents. 2-hydroxyethanethiolato(2,2',2'-terpyridine)-platinum(II) monocation binds strongly to DNA by intercalation. Proc Natl Acad Sci U S A. 1974 Oct;71(10):3839–3843. doi: 10.1073/pnas.71.10.3839. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kharkevich D. A., Skoldinov A. P. On some principles of interaction of curare-like agents with acetylcholine receptors of skeletal muscles. J Pharm Pharmacol. 1980 Nov;32(11):733–739. doi: 10.1111/j.2042-7158.1980.tb13057.x. [DOI] [PubMed] [Google Scholar]
- Kitz R. J., Karis J. H., Ginsburg S. A study in vitro of new short-acting, non-depolarizing neuromuscular blocking agents. Biochem Pharmacol. 1969 Apr;18(4):871–881. doi: 10.1016/0006-2952(69)90058-6. [DOI] [PubMed] [Google Scholar]
- LILEY A. W., NORTH K. A. An electrical investigation of effects of repetitive stimulation on mammalian neuromuscular junction. J Neurophysiol. 1953 Sep;16(5):509–527. doi: 10.1152/jn.1953.16.5.509. [DOI] [PubMed] [Google Scholar]
- Lee C. Y., Chang S. L., Kau S. T., Luh S. H. Chromatographic separation of the venom of Bungarus multicinctus and characterization of its components. J Chromatogr. 1972 Oct 5;72(1):71–82. doi: 10.1016/0021-9673(72)80009-8. [DOI] [PubMed] [Google Scholar]
- Miledi R., Potter L. T. Acetylcholine receptors in muscle fibres. Nature. 1971 Oct 29;233(5322):599–603. doi: 10.1038/233599a0. [DOI] [PubMed] [Google Scholar]
- PATON W. D. M., ZAIMIS E. The methonium. Pharmacol Rev. 1952 Sep;4(3):219–253. [PubMed] [Google Scholar]
- Standaert F. G. Release of transmitter at the neuromuscular junction. Br J Anaesth. 1982 Feb;54(2):131–145. doi: 10.1093/bja/54.2.131. [DOI] [PubMed] [Google Scholar]
- Wang J. D., Li W. E., Hu F. C., Hu K. H. Occupational risk and the development of premalignant skin lesions among paraquat manufacturers. Br J Ind Med. 1987 Mar;44(3):196–200. doi: 10.1136/oem.44.3.196. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wilson D. F. Influence of presynaptic receptors on neuromuscular transmission in rat. Am J Physiol. 1982 May;242(5):C366–C372. doi: 10.1152/ajpcell.1982.242.5.C366. [DOI] [PubMed] [Google Scholar]
