Abstract
1 The effects of the venom of the scorpion (Tityus serrulatus) on nerve fibres of the rabbit cervical vagus were studied by the single sucrose-gap technique. Scorpion venom (1 microgram/ml) increased irreversibly the duration of the B component of the compound action potential of the vagus nerves, leaving the C component with its normal configuration. Tetrodotoxin (200 nM) suppressed the prolongation of the action potential duration in venom-treated B fibres. 2 At the same concentration (1 microgram/ml), scorpion venom reduced the amplitude and the rate constant of decay of the hyperpolarization produced by tetanic stimulation of non-myelinated nerve fibres. 3 A lower concentration (0.2 micrograms/ml) blocked completely the hyperpolarization of the potassium-activated response. After washing, the potassium-activated response partially recovered its amplitude but there was a significant increase in the time constant of the decay of hyperpolarization. 4 It is suggested that scorpion venom may modify the sodium pumping mechanism within fibres as well as affecting the passive and active sodium permeability systems.
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Selected References
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- Alder-Graschinsky E., Langer S. Z. Mechanism of the enhancement in transmitter release from central and peripheral noradrenergic nerve terminals induced by the purified scorpion venom, tityustoxin. Naunyn Schmiedebergs Arch Pharmacol. 1978 Jul;303(3):243–249. doi: 10.1007/BF00498050. [DOI] [PubMed] [Google Scholar]
- Birks R. I., Cohen M. W. The action of sodium pump inhibitors on neuromuscular transmission. Proc R Soc Lond B Biol Sci. 1968 Jul 9;170(1021):381–399. doi: 10.1098/rspb.1968.0046. [DOI] [PubMed] [Google Scholar]
- Birks R. I., Cohen M. W. The influence of internal sodium on the behaviour of motor nerve endings. Proc R Soc Lond B Biol Sci. 1968 Jul 9;170(1021):401–421. doi: 10.1098/rspb.1968.0047. [DOI] [PubMed] [Google Scholar]
- Gillespie J. I., Meves H. The effect of scorpion venoms on the sodium currents of the squid giant axon. J Physiol. 1980 Nov;308:479–499. doi: 10.1113/jphysiol.1980.sp013484. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gomez M. V., Diniz C. R., Barbosa T. S. A comparison of the effects of scorpion venom tityustoxin and ouabain on the release of acetylcholine from incubated slices of rat brain. J Neurochem. 1975 Feb;24(2):331–336. doi: 10.1111/j.1471-4159.1975.tb11884.x. [DOI] [PubMed] [Google Scholar]
- Narahashi T., Shapiro B. I., Deguchi T., Scuka M., Wang C. M. Effects of scorpion venom on squid axon membranes. Am J Physiol. 1972 Apr;222(4):850–857. doi: 10.1152/ajplegacy.1972.222.4.850. [DOI] [PubMed] [Google Scholar]
- Rang H. P., Ritchie J. M. On the electrogenic sodium pump in mammalian non-myelinated nerve fibres and its activation by various external cations. J Physiol. 1968 May;196(1):183–221. doi: 10.1113/jphysiol.1968.sp008502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Riccioppo Neto F. Further studies on the actions of salicylates on nerve membranes. Eur J Pharmacol. 1980 Nov 21;68(2):155–162. doi: 10.1016/0014-2999(80)90316-7. [DOI] [PubMed] [Google Scholar]
- Riccioppo Neto F. The depolarizing action of 5-HT on mammalian non-myelinated nerve fibres. Eur J Pharmacol. 1978 Jun 15;49(4):351–356. doi: 10.1016/0014-2999(78)90308-4. [DOI] [PubMed] [Google Scholar]
- Warnick J. E., Albuquerque E. X., Diniz C. R. Electrophysiological observations on the action of the purified scorpion venom, tityustoxin, on nerve and skeletal muscle of the rat. J Pharmacol Exp Ther. 1976 Jul;198(1):155–167. [PubMed] [Google Scholar]
- Zlotkin E., Shulov A. S. A simple device for collecting scorpion venom. Toxicon. 1969 Dec;7(4):331–332. doi: 10.1016/0041-0101(69)90035-x. [DOI] [PubMed] [Google Scholar]
- den Hertog A. Some further observations on the electrogenic sodium pump in non-myelinated nerve fibres. J Physiol. 1973 Jun;231(3):493–509. doi: 10.1113/jphysiol.1973.sp010245. [DOI] [PMC free article] [PubMed] [Google Scholar]