title: [Antagonistic effect of hydroxysafflor yellow A on the platelet activating factor receptor].
abstract: OBJECTIVE
  To observe the antagonistic effect of hydroxysafflor yellow A (HSYA) on the platelet activating factor (PAF).
  
  
  METHODS
  Washed rabbit platelet (WRP) aggregation and rabbit polymorphonuclear leukocytes (PMNs) aggregation induced by PAF were observed by turbidimetric assay in vitro. The PAF receptor antagonistic effect of HSYA was investigated by radio ligand binding assay (RLBA).
  
  
  RESULTS
  In RLBA the specific binding inhibition effect of HSYA was found to be concentration-dependent in three different [3H]PAF concentrations. In the experiments, WRP aggregation and rabbit PMNs aggregation induced by PAF (9.55 x 10(-10), 9.55 x 10(-6) mol.L-1) were both inhibited by HSYA in a concentration-dependent manner in vitro. The IC50 of HSYA to inhibit WRP and rabbit PMNs aggregation was 0.99 and 0.70 mmol.L-1, respectively.
  
  
  CONCLUSIONS
  The PAF receptor binding can be antagonized by HSYA.
authors.affiliation: Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China.
authors.forename: Bao-xia
authors.initials: BX
authors.lastname: Zang
authors.forename: Ming
authors.initials: M
authors.lastname: Jin
authors.forename: Nan
authors.initials: N
authors.lastname: Si
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Yong-zhe
authors.initials: YZ
authors.lastname: Piao
mesh_terms: D000818:Animals; D031178:Carthamus / Q000737:chemistry; D002449:Cell Aggregation / Q000187:drug effects; D002599:Chalcone / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009504:Neutrophils / Q000187:drug effects; D010946:Plants, Medicinal / Q000737:chemistry; D010974:Platelet Aggregation / Q000187:drug effects*; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors*; D011809:Quinones / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors*
chemical_list: D010980:Platelet Membrane Glycoproteins; D011809:Quinones; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; C085278:hydroxysafflor yellow A; D002599:Chalcone