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. 1992 Sep;107(1):101–103. doi: 10.1111/j.1476-5381.1992.tb14469.x

Suramin inhibits excitatory junction potentials in guinea-pig isolated vas deferens.

P Sneddon 1
PMCID: PMC1907592  PMID: 1330153

Abstract

1. Intracellular microelectrode recording techniques were used to investigate the action of the putative P2-purinoceptor antagonist, suramin, on sympathetic neurotransmission in the guinea-pig isolated vas deferens. 2. The resting membrane potential of the control cells was 67.4 +/- 0.7 mV (n = 48). Field stimulation of the sympathetic nerves innervating the vas deferens produced excitatory junction potentials (e.j.ps) which reached a mean magnitude of 8.5 +/- 0.8 mV (n = 23) when fully facilitated at a stimulation frequency of 0.5 Hz. 3. Introduction of suramin 1-100 microM produced no change in the resting membrane potential of the smooth muscle cells, but gradually reduced e.j.p. magnitude. Suramin, 20 microM, reduced the mean magnitude of the fully facilitated e.j.ps to 1.4 +/- 0.3 mV (n = 18). 4. After suramin-induced inhibition of e.j.ps, nerve stimulation at 1-8 Hz resulted in summation of e.j.ps to a subthreshold level. Subsequent introduction of the alpha-adrenoceptor antagonists, prazosin or phentolamine (1 microM) did not reduce the magnitude of the summated e.j.ps. 5. The results support the proposal that e.j.ps in vas deferens are mediated by adenosine 5'-triphosphate, and not by noradrenaline, and confirm that suramin can antagonize responses mediated via P2-purinoceptors.

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Selected References

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  1. Dunn P. M., Blakeley A. G. Suramin: a reversible P2-purinoceptor antagonist in the mouse vas deferens. Br J Pharmacol. 1988 Feb;93(2):243–245. doi: 10.1111/j.1476-5381.1988.tb11427.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Fedan J. S., Hogaboom G. K., O'Donnell J. P., Colby J., Westfall D. P. Contribution by purines to the neurogenic response of the vas deferens of the guinea pig. Eur J Pharmacol. 1981 Jan 5;69(1):41–53. doi: 10.1016/0014-2999(81)90600-2. [DOI] [PubMed] [Google Scholar]
  3. Hoiting B., Molleman A., Nelemans A., Den Hertog A. P2-purinoceptor-activated membrane currents and inositol tetrakisphosphate formation are blocked by suramin. Eur J Pharmacol. 1990 May 31;181(1-2):127–131. doi: 10.1016/0014-2999(90)90253-3. [DOI] [PubMed] [Google Scholar]
  4. Hoyle C. H., Knight G. E., Burnstock G. Suramin antagonizes responses to P2-purinoceptor agonists and purinergic nerve stimulation in the guinea-pig urinary bladder and taenia coli. Br J Pharmacol. 1990 Mar;99(3):617–621. doi: 10.1111/j.1476-5381.1990.tb12979.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Leff P., Wood B. E., O'Connor S. E. Suramin is a slowly-equilibrating but competitive antagonist at P2x-receptors in the rabbit isolated ear artery. Br J Pharmacol. 1990 Nov;101(3):645–649. doi: 10.1111/j.1476-5381.1990.tb14134.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Meldrum L. A., Burnstock G. Evidence that ATP acts as a co-transmitter with noradrenaline in sympathetic nerves supplying the guinea-pig vas deferens. Eur J Pharmacol. 1983 Aug 19;92(1-2):161–163. doi: 10.1016/0014-2999(83)90126-7. [DOI] [PubMed] [Google Scholar]
  7. Schlicker E., Urbanek E., Göthert M. ATP, alpha,beta-methylene ATP and suramin as tools for characterization of vascular P2x receptors in the pithed rat. J Auton Pharmacol. 1989 Oct;9(5):357–366. doi: 10.1111/j.1474-8673.1989.tb00072.x. [DOI] [PubMed] [Google Scholar]
  8. Sneddon P., Burnstock G. Inhibition of excitatory junction potentials in guinea-pig vas deferens by alpha, beta-methylene-ATP: further evidence for ATP and noradrenaline as cotransmitters. Eur J Pharmacol. 1984 Apr 13;100(1):85–90. doi: 10.1016/0014-2999(84)90318-2. [DOI] [PubMed] [Google Scholar]
  9. Sneddon P., Westfall D. P., Colby J., Fedan J. S. A pharmacological investigation of the biphasic nature of the contractile response of rabbit and rat vas deferens to field stimulation. Life Sci. 1984 Nov 5;35(19):1903–1912. doi: 10.1016/0024-3205(84)90470-3. [DOI] [PubMed] [Google Scholar]
  10. Sneddon P., Westfall D. P., Fedan J. S. Cotransmitters in the motor nerves of the guinea pig vas deferens: electrophysiological evidence. Science. 1982 Nov 12;218(4573):693–695. doi: 10.1126/science.6291151. [DOI] [PubMed] [Google Scholar]
  11. Sneddon P., Westfall D. P. Pharmacological evidence that adenosine triphosphate and noradrenaline are co-transmitters in the guinea-pig vas deferens. J Physiol. 1984 Feb;347:561–580. doi: 10.1113/jphysiol.1984.sp015083. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Stjärne L., Astrand P. Discrete events measure single quanta of adenosine 5'-triphosphate secreted from sympathetic nerves of guinea-pig and mouse vas deferens. Neuroscience. 1984 Sep;13(1):21–28. doi: 10.1016/0306-4522(84)90256-2. [DOI] [PubMed] [Google Scholar]
  13. Urbanek E., Nickel P., Schlicker E. Antagonistic properties of four suramin-related compounds at vascular purine P2X receptors in the pithed rat. Eur J Pharmacol. 1990 Jan 10;175(2):207–210. doi: 10.1016/0014-2999(90)90232-u. [DOI] [PubMed] [Google Scholar]
  14. von Kügelgen I., Bültmann R., Starke K. Interaction of adenine nucleotides, UTP and suramin in mouse vas deferens: suramin-sensitive and suramin-insensitive components in the contractile effect of ATP. Naunyn Schmiedebergs Arch Pharmacol. 1990 Aug;342(2):198–205. doi: 10.1007/BF00166965. [DOI] [PubMed] [Google Scholar]
  15. von Kügelgen I., Starke K. Noradrenaline-ATP co-transmission in the sympathetic nervous system. Trends Pharmacol Sci. 1991 Sep;12(9):319–324. doi: 10.1016/0165-6147(91)90587-i. [DOI] [PubMed] [Google Scholar]

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