Ageing influences the effect of pre-hypoxic administration of clonidine, an alpha₂-adrenoceptor agonist, on post-hypoxic vasomotricity

M J Gourdin, O Ponchau, J Jamart, M De Kock

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Abstract

In a previous study, we showed that clonidine, an α₂-adrenoceptor agonist, administered prior to hypoxia improves post-hypoxic contractility (PC) and endothelium-dependent dilatation (PED) in isolated young rat aortas. These effects were not investigated in old rats. Ageing influences vascular physiology and modifies the response to vasoactive drugs. Some drugs, such as simvastatin, improve endothelial function, a pivotal component of vascular homeostasis. This study intends to investigate the effect of pre-hypoxic clonidine administration on post-hypoxic vasomotricity in old rats with or without simvastatin. Isolated aortic rings from young and old rats were submitted to hypoxia/reoxygenation (20 min/40 min). For each aorta ring from one rat, clonidine (10⁻⁵ M) was administered in two randomised baths and washed out before hypoxia; two other baths constituted the control group. In some experiments, the old rats were treated with simvastatin (10 mg x kg⁻¹ x day⁻¹) 3 days prior to hypoxia. PED and PC were assessed in all baths. Clonidine enhances PED in young rats (p<0.001) but decreases it in old rats (p=0.038). In young rats, clonidine improves PC (p<0.001), but this effect is not present in old rats (p=0.339). Without endothelium, clonidine does not influence PC in young rats (p= 0.687) but decreases it in old rats (p<0.001). In the simvastatin group, clonidine improves PED (p<0.001) but does not influence PC (p=0.203). In young rats, clonidine increases PED and PC, while it decreases PED and does not influence PC in old rats. With simvastatin, clonidine improves PED but does not influence PC.

Original languageEnglish
Pages (from-to)165-171
Number of pages7
JournalJournal of physiology and pharmacology : an official journal of the Polish Physiological Society
Volume63
Issue number2
Publication statusPublished - 2012

Fingerprint

Clonidine
Adrenergic Receptors
Endothelium
Dilatation
Simvastatin
Baths
Blood Vessels
Aorta
Pharmaceutical Preparations
Homeostasis

Keywords

  • Adrenergic alpha-2 Receptor Agonists
  • Aging
  • Animals
  • Anoxia
  • Aorta, Thoracic
  • Clonidine
  • Endothelium, Vascular
  • In Vitro Techniques
  • Male
  • Rats
  • Rats, Wistar
  • Vasodilation
  • Journal Article
  • Research Support, Non-U.S. Gov't

Cite this

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title = "Ageing influences the effect of pre-hypoxic administration of clonidine, an alpha₂-adrenoceptor agonist, on post-hypoxic vasomotricity",
abstract = "In a previous study, we showed that clonidine, an α₂-adrenoceptor agonist, administered prior to hypoxia improves post-hypoxic contractility (PC) and endothelium-dependent dilatation (PED) in isolated young rat aortas. These effects were not investigated in old rats. Ageing influences vascular physiology and modifies the response to vasoactive drugs. Some drugs, such as simvastatin, improve endothelial function, a pivotal component of vascular homeostasis. This study intends to investigate the effect of pre-hypoxic clonidine administration on post-hypoxic vasomotricity in old rats with or without simvastatin. Isolated aortic rings from young and old rats were submitted to hypoxia/reoxygenation (20 min/40 min). For each aorta ring from one rat, clonidine (10⁻⁵ M) was administered in two randomised baths and washed out before hypoxia; two other baths constituted the control group. In some experiments, the old rats were treated with simvastatin (10 mg x kg⁻¹ x day⁻¹) 3 days prior to hypoxia. PED and PC were assessed in all baths. Clonidine enhances PED in young rats (p<0.001) but decreases it in old rats (p=0.038). In young rats, clonidine improves PC (p<0.001), but this effect is not present in old rats (p=0.339). Without endothelium, clonidine does not influence PC in young rats (p= 0.687) but decreases it in old rats (p<0.001). In the simvastatin group, clonidine improves PED (p<0.001) but does not influence PC (p=0.203). In young rats, clonidine increases PED and PC, while it decreases PED and does not influence PC in old rats. With simvastatin, clonidine improves PED but does not influence PC.",
keywords = "Adrenergic alpha-2 Receptor Agonists, Aging, Animals, Anoxia, Aorta, Thoracic, Clonidine, Endothelium, Vascular, In Vitro Techniques, Male, Rats, Rats, Wistar, Vasodilation, Journal Article, Research Support, Non-U.S. Gov't",
author = "Gourdin, {M J} and O Ponchau and J Jamart and {De Kock}, M",
year = "2012",
language = "English",
volume = "63",
pages = "165--171",
journal = "Journal of physiology and pharmacology : an official journal of the Polish Physiological Society",
issn = "0867-5910",
publisher = "Polskie Towarzystwo Fizjologiczne",
number = "2",

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TY - JOUR

T1 - Ageing influences the effect of pre-hypoxic administration of clonidine, an alpha₂-adrenoceptor agonist, on post-hypoxic vasomotricity

AU - Gourdin, M J

AU - Ponchau, O

AU - Jamart, J

AU - De Kock, M

PY - 2012

Y1 - 2012

N2 - In a previous study, we showed that clonidine, an α₂-adrenoceptor agonist, administered prior to hypoxia improves post-hypoxic contractility (PC) and endothelium-dependent dilatation (PED) in isolated young rat aortas. These effects were not investigated in old rats. Ageing influences vascular physiology and modifies the response to vasoactive drugs. Some drugs, such as simvastatin, improve endothelial function, a pivotal component of vascular homeostasis. This study intends to investigate the effect of pre-hypoxic clonidine administration on post-hypoxic vasomotricity in old rats with or without simvastatin. Isolated aortic rings from young and old rats were submitted to hypoxia/reoxygenation (20 min/40 min). For each aorta ring from one rat, clonidine (10⁻⁵ M) was administered in two randomised baths and washed out before hypoxia; two other baths constituted the control group. In some experiments, the old rats were treated with simvastatin (10 mg x kg⁻¹ x day⁻¹) 3 days prior to hypoxia. PED and PC were assessed in all baths. Clonidine enhances PED in young rats (p<0.001) but decreases it in old rats (p=0.038). In young rats, clonidine improves PC (p<0.001), but this effect is not present in old rats (p=0.339). Without endothelium, clonidine does not influence PC in young rats (p= 0.687) but decreases it in old rats (p<0.001). In the simvastatin group, clonidine improves PED (p<0.001) but does not influence PC (p=0.203). In young rats, clonidine increases PED and PC, while it decreases PED and does not influence PC in old rats. With simvastatin, clonidine improves PED but does not influence PC.

AB - In a previous study, we showed that clonidine, an α₂-adrenoceptor agonist, administered prior to hypoxia improves post-hypoxic contractility (PC) and endothelium-dependent dilatation (PED) in isolated young rat aortas. These effects were not investigated in old rats. Ageing influences vascular physiology and modifies the response to vasoactive drugs. Some drugs, such as simvastatin, improve endothelial function, a pivotal component of vascular homeostasis. This study intends to investigate the effect of pre-hypoxic clonidine administration on post-hypoxic vasomotricity in old rats with or without simvastatin. Isolated aortic rings from young and old rats were submitted to hypoxia/reoxygenation (20 min/40 min). For each aorta ring from one rat, clonidine (10⁻⁵ M) was administered in two randomised baths and washed out before hypoxia; two other baths constituted the control group. In some experiments, the old rats were treated with simvastatin (10 mg x kg⁻¹ x day⁻¹) 3 days prior to hypoxia. PED and PC were assessed in all baths. Clonidine enhances PED in young rats (p<0.001) but decreases it in old rats (p=0.038). In young rats, clonidine improves PC (p<0.001), but this effect is not present in old rats (p=0.339). Without endothelium, clonidine does not influence PC in young rats (p= 0.687) but decreases it in old rats (p<0.001). In the simvastatin group, clonidine improves PED (p<0.001) but does not influence PC (p=0.203). In young rats, clonidine increases PED and PC, while it decreases PED and does not influence PC in old rats. With simvastatin, clonidine improves PED but does not influence PC.

KW - Adrenergic alpha-2 Receptor Agonists

KW - Aging

KW - Animals

KW - Anoxia

KW - Aorta, Thoracic

KW - Clonidine

KW - Endothelium, Vascular

KW - In Vitro Techniques

KW - Male

KW - Rats

KW - Rats, Wistar

KW - Vasodilation

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

M3 - Article

C2 - 22653903

VL - 63

SP - 165

EP - 171

JO - Journal of physiology and pharmacology : an official journal of the Polish Physiological Society

JF - Journal of physiology and pharmacology : an official journal of the Polish Physiological Society

SN - 0867-5910

IS - 2

ER -