钙通道和钾通道参与丹参和葛根汤诱导的猪冠状动脉左前降支舒张

Fung, K.P.; 509A, Lo Kwee-Seong Integrated Biomedical Sciences Building, Area 39, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; email:kpfung@cuhk.edu.hk

Danshen (Salviae Miltiorrhizae Radix) and Gegen (Puerariae Lobatae Radix) have been widely used in treating cardiovascular diseases for thousands of years in China. The present study was carried out to evaluate the effects of a Danshen and Gegen decoction (DG) on the vascular reactivity of a porcine isolated coronary artery and the underlying mechanisms involved. Porcine coronary rings were precontracted with 15 nM U46619. The involvement of endothelium-dependent mechanisms was explored by removing the endothelium; the involvement of potassium channels was investigated by the pretreatment of the artery rings with various blockers, and the involvement of the calcium channels was investigated by incubating the artery rings with Ca 2+-free buffer and priming them with high [K +] prior to adding CaCl 2 to elicit contraction. The involvement of Ca 2+ sensitization was explored by evaluating the Rho-activity expression. The results revealed that DG elicited a concentration-dependent relaxation on a U46619-precontracted coronary artery ring. These relaxation responses were not altered by the pretreatment of inhibitors of endothelium-related dilator synthases, cGMP and cAMP pathway inhibitors, potassium channel (BK Ca, SK Ca, K V and K ATP) blockers and endothelium removal. The K IR channel blocker BaCl 2 only slightly attenuated the DG-induced relaxation. However, the Ca 2+-induced artery contraction was inhibited by DG. Additionally, the expression of the phosphorylated myosin light chain was inhibited by DG whereas the activity of RhoA was not affected. Therefore, DG could be a useful cardioprotective agent for vasodilation in patients who have hypertension. © 2012 Elsevier GmbH. All rights reserved.

Institute of Chinese Medicine, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong