Characterisation of the effects of the phospholipase c inhibitor U73122 on P2Y receptor-mediated contractions of the rat isolated pulmonary artery

A. Tengah, C. Kennedy

Research output: Contribution to journalConference Contribution

Abstract

P2Y receptor agonists induce vasodilation via endothelial P2Y receptors and vasoconstriction via smooth muscle P2Y receptors (Chootip et al., 2002). However, the intracellular signalling pathways by which vasoconstriction is induced are not well characterised. The aim of this study was to determine the role of phospholipase C (PLC) in nucleotide-evoked vasoconstriction of rat small intrapulmonary artery (SPA) using the PI-PLC inhibitor U73122. 5 mm rings of endothelium-denuded rat SPA were mounted under isometric conditions in 1 mL organ baths at 37C and a resting tension of 0.5 g. Contractions were elicited by addition of the P2Y receptor agonists UTP and UDP (300 lM), the FP receptor agonist PGF2a (10 lM) or KCl (40 mM) to the bath. UTP, UDP and PGF2a each evoked slowly developing contractions, which reached a peak within 5 min. Pre-incubation with U-73122 (1 lM and 3 lM) for 15 min had no effect on the resting tone of the arteries nor on the amplitude of the contractions evoked by UTP (n = 5), UDP (n = 5), PGF2a (n = 5) or KCl (n = 5). Increasing the concentration of U73122 to 10 lM and the preincubation period to 30 min, also left the responses to UTP, UDP and KCl unchanged (n = 6). In contrast, the contractions to PGF2a were inhibited significantly under these conditions (77 ± 6% of control, n = 6, P < 0.05). These results show that the PI-PLC inhibitor U73122 had no effect on P2Y receptormediated contractions of rat pulmonary artery under conditions that inhibited the responses induced by PGF2a. This calls into question the involvement of PLC in the P2Y receptor-mediated contraction of rat pulmonary artery and further studies are ongoing to determine the involvement of other intracellular signalling components.
LanguageEnglish
Pages60-60
Number of pages0
JournalFundamental and Clinical Pharmacology
Volume22
Issue numberS2
DOIs
Publication statusPublished - Aug 2008

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Uridine Diphosphate
Phospholipases
Type C Phospholipases
Pulmonary Artery
Uridine Triphosphate
Vasoconstriction
Arteries
Baths
Vasodilation
Endothelium
Smooth Muscle
Nucleotides
1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione

Keywords

  • phopholipase c inhibitor
  • U73122
  • P2Y receptor-mediated contractions
  • rat isolated pulmonary artery

Cite this

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title = "Characterisation of the effects of the phospholipase c inhibitor U73122 on P2Y receptor-mediated contractions of the rat isolated pulmonary artery",
abstract = "P2Y receptor agonists induce vasodilation via endothelial P2Y receptors and vasoconstriction via smooth muscle P2Y receptors (Chootip et al., 2002). However, the intracellular signalling pathways by which vasoconstriction is induced are not well characterised. The aim of this study was to determine the role of phospholipase C (PLC) in nucleotide-evoked vasoconstriction of rat small intrapulmonary artery (SPA) using the PI-PLC inhibitor U73122. 5 mm rings of endothelium-denuded rat SPA were mounted under isometric conditions in 1 mL organ baths at 37C and a resting tension of 0.5 g. Contractions were elicited by addition of the P2Y receptor agonists UTP and UDP (300 lM), the FP receptor agonist PGF2a (10 lM) or KCl (40 mM) to the bath. UTP, UDP and PGF2a each evoked slowly developing contractions, which reached a peak within 5 min. Pre-incubation with U-73122 (1 lM and 3 lM) for 15 min had no effect on the resting tone of the arteries nor on the amplitude of the contractions evoked by UTP (n = 5), UDP (n = 5), PGF2a (n = 5) or KCl (n = 5). Increasing the concentration of U73122 to 10 lM and the preincubation period to 30 min, also left the responses to UTP, UDP and KCl unchanged (n = 6). In contrast, the contractions to PGF2a were inhibited significantly under these conditions (77 ± 6{\%} of control, n = 6, P < 0.05). These results show that the PI-PLC inhibitor U73122 had no effect on P2Y receptormediated contractions of rat pulmonary artery under conditions that inhibited the responses induced by PGF2a. This calls into question the involvement of PLC in the P2Y receptor-mediated contraction of rat pulmonary artery and further studies are ongoing to determine the involvement of other intracellular signalling components.",
keywords = "phopholipase c inhibitor, U73122, P2Y receptor-mediated contractions, rat isolated pulmonary artery",
author = "A. Tengah and C. Kennedy",
note = "This meeting abstract was also published in Purinergic Signalling (2008), 4 (S1), ppS80-S81 (This is a variant record)",
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volume = "22",
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TY - JOUR

T1 - Characterisation of the effects of the phospholipase c inhibitor U73122 on P2Y receptor-mediated contractions of the rat isolated pulmonary artery

AU - Tengah, A.

AU - Kennedy, C.

N1 - This meeting abstract was also published in Purinergic Signalling (2008), 4 (S1), ppS80-S81 (This is a variant record)

PY - 2008/8

Y1 - 2008/8

N2 - P2Y receptor agonists induce vasodilation via endothelial P2Y receptors and vasoconstriction via smooth muscle P2Y receptors (Chootip et al., 2002). However, the intracellular signalling pathways by which vasoconstriction is induced are not well characterised. The aim of this study was to determine the role of phospholipase C (PLC) in nucleotide-evoked vasoconstriction of rat small intrapulmonary artery (SPA) using the PI-PLC inhibitor U73122. 5 mm rings of endothelium-denuded rat SPA were mounted under isometric conditions in 1 mL organ baths at 37C and a resting tension of 0.5 g. Contractions were elicited by addition of the P2Y receptor agonists UTP and UDP (300 lM), the FP receptor agonist PGF2a (10 lM) or KCl (40 mM) to the bath. UTP, UDP and PGF2a each evoked slowly developing contractions, which reached a peak within 5 min. Pre-incubation with U-73122 (1 lM and 3 lM) for 15 min had no effect on the resting tone of the arteries nor on the amplitude of the contractions evoked by UTP (n = 5), UDP (n = 5), PGF2a (n = 5) or KCl (n = 5). Increasing the concentration of U73122 to 10 lM and the preincubation period to 30 min, also left the responses to UTP, UDP and KCl unchanged (n = 6). In contrast, the contractions to PGF2a were inhibited significantly under these conditions (77 ± 6% of control, n = 6, P < 0.05). These results show that the PI-PLC inhibitor U73122 had no effect on P2Y receptormediated contractions of rat pulmonary artery under conditions that inhibited the responses induced by PGF2a. This calls into question the involvement of PLC in the P2Y receptor-mediated contraction of rat pulmonary artery and further studies are ongoing to determine the involvement of other intracellular signalling components.

AB - P2Y receptor agonists induce vasodilation via endothelial P2Y receptors and vasoconstriction via smooth muscle P2Y receptors (Chootip et al., 2002). However, the intracellular signalling pathways by which vasoconstriction is induced are not well characterised. The aim of this study was to determine the role of phospholipase C (PLC) in nucleotide-evoked vasoconstriction of rat small intrapulmonary artery (SPA) using the PI-PLC inhibitor U73122. 5 mm rings of endothelium-denuded rat SPA were mounted under isometric conditions in 1 mL organ baths at 37C and a resting tension of 0.5 g. Contractions were elicited by addition of the P2Y receptor agonists UTP and UDP (300 lM), the FP receptor agonist PGF2a (10 lM) or KCl (40 mM) to the bath. UTP, UDP and PGF2a each evoked slowly developing contractions, which reached a peak within 5 min. Pre-incubation with U-73122 (1 lM and 3 lM) for 15 min had no effect on the resting tone of the arteries nor on the amplitude of the contractions evoked by UTP (n = 5), UDP (n = 5), PGF2a (n = 5) or KCl (n = 5). Increasing the concentration of U73122 to 10 lM and the preincubation period to 30 min, also left the responses to UTP, UDP and KCl unchanged (n = 6). In contrast, the contractions to PGF2a were inhibited significantly under these conditions (77 ± 6% of control, n = 6, P < 0.05). These results show that the PI-PLC inhibitor U73122 had no effect on P2Y receptormediated contractions of rat pulmonary artery under conditions that inhibited the responses induced by PGF2a. This calls into question the involvement of PLC in the P2Y receptor-mediated contraction of rat pulmonary artery and further studies are ongoing to determine the involvement of other intracellular signalling components.

KW - phopholipase c inhibitor

KW - U73122

KW - P2Y receptor-mediated contractions

KW - rat isolated pulmonary artery

UR - http://strathprints.strath.ac.uk/19500/

U2 - 10.1111/j.1472-8206.2008.00595.x

DO - 10.1111/j.1472-8206.2008.00595.x

M3 - Conference Contribution

VL - 22

SP - 60

EP - 60

JO - Fundamental and Clinical Pharmacology

T2 - Fundamental and Clinical Pharmacology

JF - Fundamental and Clinical Pharmacology

SN - 0767-3981

IS - S2

ER -