Original ArticleVasorelaxant Activities of Danhong Injection and Their Differential Effects on the Rat Abdominal Aorta and Mesenteric ArterySu, Xianming MD, PhD*; Zhi, Xiaowen MS*,†; Cui, Ting MS*,‡; Zheng, Qiaowei MS*; Wang, Shixiang PhD§; Cao, Yongxiao PhD¶; Cui, Changcong MD*; Feng, Weiyi PhD*Author Information *First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, China; †Shaanxi General Hospital of Chinese People's Armed Police Forces, Xi'an, China; ‡China Resources Sanjiu Medical & Pharmaceutical Co. Ltd, Shenzhen, China; §College of Life Science, Northwest University, Xi'an, China; and ¶Medical College of Xi'an Jiaotong University, Xi'an, China. Reprints: Weiyi Feng, PhD, Pharmacy Department, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, 277 Yanta West Rd, Xi'an 710061, China (e-mail: firstname.lastname@example.org). Supported by grants from the Natural Science Foundation of China (81071765 and 81372379) and The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2011, the 41th package), and Technological Project of Shaanxi Province (2012K15-02-01). W. Feng designed and performed research, collected and analyzed data and wrote manuscript. X. Su designed research, analyzed data and wrote manuscript. X. Zhi performed research. T. Cui performed research. Q. Zheng and S. Wang collected and analyzed data. Y. Cao designed research. C. Cui designed research and analyzed data. X. Su, X. Zhi, and T. Cui have contributed equally. The authors report no conflicts of interest. Received June 11, 2014 Accepted September 02, 2014 Journal of Cardiovascular Pharmacology: January 2015 - Volume 65 - Issue 1 - p 62-71 doi: 10.1097/FJC.0000000000000164 Buy Metrics Abstract Abstract: Previous studies have found that Danhong injection (DHI), an extensively used herbal extract preparation in China, might be a powerful vasodilator. The aims of this study were to determine the vascular activity of DHI and its effects on arteries of different sizes. The results showed that DHI significantly inhibited rat-hindquarters and rabbit-ear vasoconstriction elicited by norepinephrine (NE) perfusion and markedly relaxed KCl-contracted and NE-contracted rat abdominal aortic and mesenteric artery rings. The endothelium made only a minor contribution to the vasorelaxant effect of DHI on artery segments. The vasorelaxant effect of DHI varied with the artery size, with larger arteries exhibiting a more sensitive and potent vasodilator response. DHI relaxed NE-induced vasoconstriction probably through inhibition of the intracellular Ca2+ release through the inositol triphosphate receptor system in the abdominal aorta and mesenteric artery, along with blockage of extracellular Ca2+ influx through the receptor-linked Ca2+ channels in the mesenteric artery. In addition, DHI completely relaxed KCl-induced contraction in both of the arteries, suggesting that inhibition of Ca2+ influx through voltage-gated Ca2+ channels is involved in the vasorelaxant effect of DHI. This elucidation of the vascular effects of DHI and the underlying mechanisms could lead to improved clinical applications. © 2015 by Lippincott Williams & Wilkins.