Author/Editor		Japelj, Irena; Budihna, Metka V; Stanovnik, Lovro; Krisch, Igor
Title		Stereoselective and endothelium-independent action of nicardipine on the isolated porcine coronary artery
Type		članek
Source		Eur J Pharmacol
Vol. and No.		Letnik 369
Publication year		1999
Volume		str. 43-7
Language		eng
Abstract		The qualitative and quantitative effects of the (+)-S and (-)-R enantiomers and of the racemic mixture of the Ca2+ channel antagonist, nicardipine, were compared on the isolated porcine coronary artery with intact and removed endothelium. All three forms of nicardipine inhibited the contractions induced by KC1 (5-90 mM) in both vessel preparations. The potency (IC50) of the (+)-S and (-)-R enantiomers and of the racemic mixture was 6.6, 31.8 and 10.9 nM in the vessel with endothelium and 6.4, 41.9 and 9.8 nM inthe vessel without endothelium. The parameters of the concentration-response curves for each form of nicardipine at a submaximal KCI (60 mM) concentration and the potency ratios between the two enantiomers (( + )-S/( - )-R) were not statistically significantly different (P>0.05) in the two vessel preparations. In conclusion, qualitatively, all three forms of nicardipine showed only Ca2+ channel antagonistic effects in both vessel prepartions. Quantitatively, the inhibition of contraction was stereoselective, the ( + )-S enantiomer being the most potent, and was endothelium-independent.
Descriptors		STEREOISOMERISM NICARDIPINE CALCIUM CHANNEL AGONISTS CALCIUM CHANNELS CORONARY VESSELS ENDOTHELIUM, VASCULAR DISEASE MODELS, ANIMAL