title: The effects of hydroxysafflor yellow A on blood pressure and cardiac function.
abstract: OBJECTIVE
  This work aims to investigate the effects of HSYA on cardiac function and blood pressure.
  
  
  METHODS
  To evaluate changes in mean arterial pressure (MAP) and heart rate (HR), different groups of pentobarbitone-anesthetized normotensive and spontaneously hypertensive rats (SHR) were treated with intravenous HSYA (0.1-3 mg/kg). Isolated WKY rat hearts in Langendorff system were employed for examining the effect of HSYA on hemodynamic. After 30 min equilibration time the isolated hearts were perfused with HSYA (30 μmol/L) in a stepwise fashion. Potassium channel inhibitors were used to determine the role of potassium channel activation in HSYA effect.
  
  
  RESULTS
  Intravenous injection of the HSYA significantly reduced MAP and HR in both normotensive rats and SHR in a dose-dependent manner. HSYA reduced left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of increase of left ventricular pressure (+dp/dt(max)) and heart rate (HR) in a dose-dependent manner. HSYA had no remarkable effect on the maximum rate of decrease of left ventricular pressure (-dp/dt(max)); BK(Ca) and K(ATP) blocker can weakened the inhibitory effect of HSYA on heart function and HR, but K(V) and K(ACh) blocker did not significantly weaken the HSYA effects.
  
  
  CONCLUSIONS
  Our results show that HSYA could significantly reduce blood pressure and heart rate, which may be related to activation of BK(Ca) and K(ATP) channels.
authors.affiliation: Department of Physiology, Basic Medical College, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Pei-He
authors.initials: PH
authors.lastname: Nie
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Zhang
authors.forename: Wei-Fang
authors.initials: WF
authors.lastname: Rong
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Zhi
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D002121:Calcium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use; D015220:Calcium Channels; D031187:Carthamus tinctorius; D002599:Chalcone / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D035264:Flowers; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000188:drug therapy*; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D026902:Potassium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use; D015221:Potassium Channels / Q000187:drug effects; D011809:Quinones / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012016:Reference Values; D016277:Ventricular Function, Left / Q000187:drug effects*
chemical_list: D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010936:Plant Extracts; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011809:Quinones; C085278:hydroxysafflor yellow A; D002599:Chalcone