Effects of praeruptorin C and E isolated from 'Qian-Hu' on swine coronary artery and guinea-pig atria.
Praeruptorin C and E isolated from Peucedanum praeruptorum Dunn. decreased the maximum contractile effect of Ca2+ in potassium-depolarized swine coronary strips and shifted the concentration-response curve to the right in a non-parallel manner. The calcium antagonistic activity of praeruptorin C and E expressed as pD'2 value was 5.7 and 5.2, respectively. Nifedipine, with a pD'2 value of 6.88, was used as a known calcium antagonistic drug to compare the potency of the drugs studied. The relaxation induced by praeruptorin C was concentration-dependent and the IC50 value was 79 microM. Praeruptorin C also reduced the maximum contractile response and shifted the concentration-response curve for calcium to the right in a non-parallel manner in potassium-depolarized guinea-pig left atria (pD'2 = 5.52) but its potency was much less than that of nifedipine (pD'2 = 7.19). The results suggest that praeruptorin C and E relaxed swine coronary artery and decreased contractility in guinea-pig left atria. These effects are similar in many respects to those displayed by drugs that have calcium entry blocking activity.
Rao
M R
MR
Department of Cardiovascular Pharmacology, Nanjing Medical College, China.
Shen
X H
XH
Zou
X
X
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers; D003331:Coronary Vessels / Q000187:drug effects; D003374:Coumarins / Q000494:pharmacology*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects*
D002121:Calcium Channel Blockers; D003374:Coumarins; D004365:Drugs, Chinese Herbal; C036455:praeruptorin E; C058808:praeruptorin C; D002118:Calcium