Abstract
A study was made of the effects of hydralazine on K+ contractures in rabbit aortic strips. Measurements were made of effects on tension generation, Ca++ accumulation measured using 45Ca++ (lanthanum method) and 45Ca++ efflux. Hydralazine relaxed established K+ contractures and inhibited tension development when tissue exposure to hydralazine preceded K+ depolarization. Both the threshold and the maximum tension responses of strips to Ca++ (K+-depolarized tissues) were altered by hydralazine in a dose-dependent manner. The Ca++ uptake associated with K+ depolarization was inhibited by relaxant doses of hydralazine; however, hydralazine did not significantly affect the rate of 45Ca++ efflux. Hydralazine also raised the threshold to the inhibitory (relaxant) effects of higher (>2.5 mM) bath concentrations of Ca++. It is suggested that hydralazine inhibits K+ contractures in aortic strips by interference with the entry of Ca++ into the cell, reflecting an effect of hydralazine at the cell surface membrane.
| Original language | English |
|---|---|
| Pages (from-to) | 40-48 |
| Number of pages | 9 |
| Journal | Journal of Pharmacology and Experimental Therapeutics |
| Volume | 207 |
| Issue number | 1 |
| State | Published - 1 Dec 1978 |
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Interaction of hydralazine with tension development and mechanisms of calcium accumulation in K+-stimulated rabbit aortic strips. / McLean, A. J.; Du Souich, P.; Barron, Kirk; Briggs, A. H.
In: Journal of Pharmacology and Experimental Therapeutics, Vol. 207, No. 1, 01.12.1978, p. 40-48.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Interaction of hydralazine with tension development and mechanisms of calcium accumulation in K+-stimulated rabbit aortic strips
AU - McLean, A. J.
AU - Du Souich, P.
AU - Barron, Kirk
AU - Briggs, A. H.
PY - 1978/12/1
Y1 - 1978/12/1
N2 - A study was made of the effects of hydralazine on K+ contractures in rabbit aortic strips. Measurements were made of effects on tension generation, Ca++ accumulation measured using 45Ca++ (lanthanum method) and 45Ca++ efflux. Hydralazine relaxed established K+ contractures and inhibited tension development when tissue exposure to hydralazine preceded K+ depolarization. Both the threshold and the maximum tension responses of strips to Ca++ (K+-depolarized tissues) were altered by hydralazine in a dose-dependent manner. The Ca++ uptake associated with K+ depolarization was inhibited by relaxant doses of hydralazine; however, hydralazine did not significantly affect the rate of 45Ca++ efflux. Hydralazine also raised the threshold to the inhibitory (relaxant) effects of higher (>2.5 mM) bath concentrations of Ca++. It is suggested that hydralazine inhibits K+ contractures in aortic strips by interference with the entry of Ca++ into the cell, reflecting an effect of hydralazine at the cell surface membrane.
AB - A study was made of the effects of hydralazine on K+ contractures in rabbit aortic strips. Measurements were made of effects on tension generation, Ca++ accumulation measured using 45Ca++ (lanthanum method) and 45Ca++ efflux. Hydralazine relaxed established K+ contractures and inhibited tension development when tissue exposure to hydralazine preceded K+ depolarization. Both the threshold and the maximum tension responses of strips to Ca++ (K+-depolarized tissues) were altered by hydralazine in a dose-dependent manner. The Ca++ uptake associated with K+ depolarization was inhibited by relaxant doses of hydralazine; however, hydralazine did not significantly affect the rate of 45Ca++ efflux. Hydralazine also raised the threshold to the inhibitory (relaxant) effects of higher (>2.5 mM) bath concentrations of Ca++. It is suggested that hydralazine inhibits K+ contractures in aortic strips by interference with the entry of Ca++ into the cell, reflecting an effect of hydralazine at the cell surface membrane.
UR - http://www.scopus.com/inward/record.url?scp=0018142646&partnerID=8YFLogxK
M3 - Article
VL - 207
SP - 40
EP - 48
JO - Journal of Pharmacology and Experimental Therapeutics
JF - Journal of Pharmacology and Experimental Therapeutics
SN - 0022-3565
IS - 1
ER -