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P2X receptors counteract the vasodilatory effects of endothelium derived hyperpolarising factor

Malmsjö, Malin LU ; Edvinsson, Lars LU and Erlinge, David LU (2000) In European Journal of Pharmacology 390(1-2). p.173-180
Abstract
Dilatory responses of extracellular nucleotides were examined in the precontracted isolated rat mesenteric artery. Dilatation mediated by endothelium-derived hyperpolarising factor (EDHF) was studied in the presence of Nomega-nitro-L-arginine (L-NOARG) and indomethacin, and was most potently induced by the selective P2Y(1) receptor agonist adenosine 5'-O-thiodiphosphate (ADPbetaS), while 2-methylthioadenosine triphosphate (2-MeSATP) and adenosine triphosphate (ATP) were almost inactive. However, after P2X receptor desensitisation (with alphabeta-methylene-adenosine triphosphate, alphabeta-MeATP), 2-MeSATP and ATP potently stimulated EDHF-mediated dilatation. This can be explained by simultaneous activation of endothelial P2Y receptors that... (More)
Dilatory responses of extracellular nucleotides were examined in the precontracted isolated rat mesenteric artery. Dilatation mediated by endothelium-derived hyperpolarising factor (EDHF) was studied in the presence of Nomega-nitro-L-arginine (L-NOARG) and indomethacin, and was most potently induced by the selective P2Y(1) receptor agonist adenosine 5'-O-thiodiphosphate (ADPbetaS), while 2-methylthioadenosine triphosphate (2-MeSATP) and adenosine triphosphate (ATP) were almost inactive. However, after P2X receptor desensitisation (with alphabeta-methylene-adenosine triphosphate, alphabeta-MeATP), 2-MeSATP and ATP potently stimulated EDHF-mediated dilatation. This can be explained by simultaneous activation of endothelial P2Y receptors that release EDHF, and depolarising P2X receptors on smooth muscle cells. Uridine triphosphate (UTP) also induced potent dilatation, suggesting EDHF release via P2Y(2)/P2Y(4) receptors. Uridine diphosphate (UDP) had only minor dilatory effects, and when pretreated with hexokinase it was almost inactive, suggesting a minor role for P2Y(6) receptors. The nitric oxide (NO) mediated dilatation was studied in the presence of charybdotoxin, apamin and indomethacin. ADPbetaS, 2-MeSATP, ATP and UTP were all potent relaxant agonists suggesting NO release via P2Y(1) and P2Y(2)/P2Y(4) receptors, while UDP was much less potent and efficacious. P2X receptor desensitisation had only minor effect on the NO-mediated dilatations. In conclusion, both EDHF and NO-mediated dilatation can be induced by activation of P2Y(1) and P2Y(2)/P2Y(4) receptors. P2X receptor stimulation of smooth muscle cells selectively counteracts the dilatory effect of EDHF. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
EDHF (endothelin-derived hyperpolarising factor), Endothelium, P2 receptor, Purine, Pyrimidine, Vasodilatation
in
European Journal of Pharmacology
volume
390
issue
1-2
pages
173 - 180
publisher
Elsevier
external identifiers
  • pmid:10708721
  • scopus:0034712072
ISSN
1879-0712
DOI
10.1016/S0014-2999(00)00010-8
language
English
LU publication?
yes
id
439794b6-6df0-48ab-a7b6-ca4be2282981 (old id 1117333)
date added to LUP
2008-07-03 11:16:36
date last changed
2017-07-30 03:42:31
@article{439794b6-6df0-48ab-a7b6-ca4be2282981,
  abstract     = {Dilatory responses of extracellular nucleotides were examined in the precontracted isolated rat mesenteric artery. Dilatation mediated by endothelium-derived hyperpolarising factor (EDHF) was studied in the presence of Nomega-nitro-L-arginine (L-NOARG) and indomethacin, and was most potently induced by the selective P2Y(1) receptor agonist adenosine 5'-O-thiodiphosphate (ADPbetaS), while 2-methylthioadenosine triphosphate (2-MeSATP) and adenosine triphosphate (ATP) were almost inactive. However, after P2X receptor desensitisation (with alphabeta-methylene-adenosine triphosphate, alphabeta-MeATP), 2-MeSATP and ATP potently stimulated EDHF-mediated dilatation. This can be explained by simultaneous activation of endothelial P2Y receptors that release EDHF, and depolarising P2X receptors on smooth muscle cells. Uridine triphosphate (UTP) also induced potent dilatation, suggesting EDHF release via P2Y(2)/P2Y(4) receptors. Uridine diphosphate (UDP) had only minor dilatory effects, and when pretreated with hexokinase it was almost inactive, suggesting a minor role for P2Y(6) receptors. The nitric oxide (NO) mediated dilatation was studied in the presence of charybdotoxin, apamin and indomethacin. ADPbetaS, 2-MeSATP, ATP and UTP were all potent relaxant agonists suggesting NO release via P2Y(1) and P2Y(2)/P2Y(4) receptors, while UDP was much less potent and efficacious. P2X receptor desensitisation had only minor effect on the NO-mediated dilatations. In conclusion, both EDHF and NO-mediated dilatation can be induced by activation of P2Y(1) and P2Y(2)/P2Y(4) receptors. P2X receptor stimulation of smooth muscle cells selectively counteracts the dilatory effect of EDHF.},
  author       = {Malmsjö, Malin and Edvinsson, Lars and Erlinge, David},
  issn         = {1879-0712},
  keyword      = {EDHF (endothelin-derived hyperpolarising factor),Endothelium,P2 receptor,Purine,Pyrimidine,Vasodilatation},
  language     = {eng},
  number       = {1-2},
  pages        = {173--180},
  publisher    = {Elsevier},
  series       = {European Journal of Pharmacology},
  title        = {P2X receptors counteract the vasodilatory effects of endothelium derived hyperpolarising factor},
  url          = {http://dx.doi.org/10.1016/S0014-2999(00)00010-8},
  volume       = {390},
  year         = {2000},
}