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Modification of arterial smooth muscle reactivity in cyclosporine A pretreated arteries
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Abstract
Background In the present study the interactions between phenylephrine - selective α1-adrenoceptor agonist, arg-vasopressine - selective agonist of vasopressine receptor type 1 (V1) and modulator - cyclosporine A were investigated.
Material and methods Experiments were performed on perfused rat tail arteries. Using classical pharmacometric methods the relationship between concentration-response curves (CRCs) for agonists performed in the absence and presence of cyclosporine A were analyzed.
Results In the presence of cyclosporine A the reduction in ED50 values for agonists was observed. Dissociation constants for agonists calculated in the presence of cyclosporine A did not differ significantly from controls.
Conclusions Changes in plots of agonists responses against receptor occupancy for agonists and changes in KA/ED50 value suggest increase in receptor reserve. This increase was not significantly reduced in the presence of losartan. Our results suggest that changes in receptor reserve are result of changes in signal transduction.
Abstract
Background In the present study the interactions between phenylephrine - selective α1-adrenoceptor agonist, arg-vasopressine - selective agonist of vasopressine receptor type 1 (V1) and modulator - cyclosporine A were investigated.
Material and methods Experiments were performed on perfused rat tail arteries. Using classical pharmacometric methods the relationship between concentration-response curves (CRCs) for agonists performed in the absence and presence of cyclosporine A were analyzed.
Results In the presence of cyclosporine A the reduction in ED50 values for agonists was observed. Dissociation constants for agonists calculated in the presence of cyclosporine A did not differ significantly from controls.
Conclusions Changes in plots of agonists responses against receptor occupancy for agonists and changes in KA/ED50 value suggest increase in receptor reserve. This increase was not significantly reduced in the presence of losartan. Our results suggest that changes in receptor reserve are result of changes in signal transduction.
Keywords
cyclosporine-A; α1-adrenoceptors; vasopressine receptors; receptor reserve
About this articleTitle
Modification of arterial smooth muscle reactivity in cyclosporine A pretreated arteries
Journal
Issue
Article type
Original paper
Pages
21-26
Published online
2007-01-24
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711
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1665
Bibliographic record
Nadciśnienie tętnicze 2007;11(1):21-26.
Keywords
cyclosporine-A
α1-adrenoceptors
vasopressine receptors
receptor reserve
Authors
Grzegorz Grześk
Iwona Świątkiewicz
Maciej Słupski
Sławomir Manysiak
Michał Wiciński
Katarzyna Szadujkis-Szadurska
Grażyna Odrowąż-Sypniewska
Leszek Szadujkis-Szadurski