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Effects of selective ETB-receptor stimulation on arterial, venous and capillary functions in cat skeletal muscle

Ekelund, Ulf LU ; Adner, Mikael LU ; Edvinsson, Lars LU and Mellander, Stefan LU (1994) In British Journal of Pharmacology 112(3). p.887-894
Abstract
1. This paper describes, in quantitative terms, the in vivo effects of two selective ETB-receptor agonists (IRL 1620 and BQ 3020) on vascular resistance (tone) in the following consecutive sections of the vascular bed of sympathectomized cat skeletal muscle: large-bore arterial resistance vessels (> 25 microns), small arterioles (< 25 microns) and the veins. The effects on capillary pressure transcapillary fluid exchange were also recorded. 2. Both IRL 1620 and BQ 3020, infused i.a. to the muscle preparation, evoked an initial transient dilator response followed by a moderate dose-dependent constrictor response, both being preferentially confined to the small arterioles. The dilator response was associated with a transient increase,... (More)
1. This paper describes, in quantitative terms, the in vivo effects of two selective ETB-receptor agonists (IRL 1620 and BQ 3020) on vascular resistance (tone) in the following consecutive sections of the vascular bed of sympathectomized cat skeletal muscle: large-bore arterial resistance vessels (> 25 microns), small arterioles (< 25 microns) and the veins. The effects on capillary pressure transcapillary fluid exchange were also recorded. 2. Both IRL 1620 and BQ 3020, infused i.a. to the muscle preparation, evoked an initial transient dilator response followed by a moderate dose-dependent constrictor response, both being preferentially confined to the small arterioles. The dilator response was associated with a transient increase, and the constrictor response with a sustained decrease, in capillary pressure, the latter causing net transcapillary fluid absorption. The capillary filtration coefficient decreased during the constrictor response, indicating constriction of terminal arterioles/precapillary sphincters. 3. The vascular responses to the ETB-receptor agonists were unaffected by blockade of endothelium-derived nitric oxide (NG-nitro-L-arginine methyl ester) and by selective ETA-receptor blockade (FR139317). However, blockade of prostacyclin production with indomethacin decreased the amplitude of the dilator response, and decreased the time required to reach a steady-state vasoconstrictor response to the ETB-receptor agonists. 4. The effect of ETB-receptor stimulation on vascular tone was also evaluated in vitro on the cat femoral artery and vein. IRL 1620 had no effect on the femoral artery but caused a weak dose-dependent relaxation in the femoral vein. This large vein relaxation response seemed to be mediated by endothelium-derived nitric oxide and not by prostacyclin.(ABSTRACT TRUNCATED AT 250 WORDS) (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Arteries, capillaries, capillary pressure, endothelins, ETA-receptor, ETB-receptor, microcirculation, prostacyclin, veins
in
British Journal of Pharmacology
volume
112
issue
3
pages
887 - 894
publisher
The British Pharmacological Society
external identifiers
  • pmid:7921617
  • scopus:0028178651
ISSN
1476-5381
language
English
LU publication?
yes
id
01cfe916-c6ef-42a9-9d68-49bbaeb6f558 (old id 1107950)
alternative location
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1910201&blobtype=pdf
date added to LUP
2008-07-23 10:15:16
date last changed
2017-08-06 04:34:29
@article{01cfe916-c6ef-42a9-9d68-49bbaeb6f558,
  abstract     = {1. This paper describes, in quantitative terms, the in vivo effects of two selective ETB-receptor agonists (IRL 1620 and BQ 3020) on vascular resistance (tone) in the following consecutive sections of the vascular bed of sympathectomized cat skeletal muscle: large-bore arterial resistance vessels (&gt; 25 microns), small arterioles (&lt; 25 microns) and the veins. The effects on capillary pressure transcapillary fluid exchange were also recorded. 2. Both IRL 1620 and BQ 3020, infused i.a. to the muscle preparation, evoked an initial transient dilator response followed by a moderate dose-dependent constrictor response, both being preferentially confined to the small arterioles. The dilator response was associated with a transient increase, and the constrictor response with a sustained decrease, in capillary pressure, the latter causing net transcapillary fluid absorption. The capillary filtration coefficient decreased during the constrictor response, indicating constriction of terminal arterioles/precapillary sphincters. 3. The vascular responses to the ETB-receptor agonists were unaffected by blockade of endothelium-derived nitric oxide (NG-nitro-L-arginine methyl ester) and by selective ETA-receptor blockade (FR139317). However, blockade of prostacyclin production with indomethacin decreased the amplitude of the dilator response, and decreased the time required to reach a steady-state vasoconstrictor response to the ETB-receptor agonists. 4. The effect of ETB-receptor stimulation on vascular tone was also evaluated in vitro on the cat femoral artery and vein. IRL 1620 had no effect on the femoral artery but caused a weak dose-dependent relaxation in the femoral vein. This large vein relaxation response seemed to be mediated by endothelium-derived nitric oxide and not by prostacyclin.(ABSTRACT TRUNCATED AT 250 WORDS)},
  author       = {Ekelund, Ulf and Adner, Mikael and Edvinsson, Lars and Mellander, Stefan},
  issn         = {1476-5381},
  keyword      = {Arteries,capillaries,capillary pressure,endothelins,ETA-receptor,ETB-receptor,microcirculation,prostacyclin,veins},
  language     = {eng},
  number       = {3},
  pages        = {887--894},
  publisher    = {The British Pharmacological Society},
  series       = {British Journal of Pharmacology},
  title        = {Effects of selective ETB-receptor stimulation on arterial, venous and capillary functions in cat skeletal muscle},
  volume       = {112},
  year         = {1994},
}