title: [Study of stinging crystals in tian nanxing].
abstract: OBJECTIVE
  To test whether the raphides in Tian Nanxing (Pinellia pedatisecta Schott) caused irritation.
  
  
  METHODS
  Scan Electron Microscope and Microscope Oberservation; Animal experimental study.
  
  
  RESULTS
  Through the comparision of unprocessed Tian Nanxing to processed ones which included 36 h, 72 h, 120 h processed samples, the great modifications in the structure of raphides, especially for the ones with barbs in the processed samples was observed with time course study. A further animal experimental study went to show that the rate of change for raphides with barbs existed a dose-reponse relationship to irritation.
  
  
  CONCLUSIONS
  Investigations of the causes of these reactions showed that raphides of calcium oxalate are, at least in part, responsible for the Tian Nanxing's irritation.
authors.affiliation: Inst of Chinese Materia Medica, China Academy of Tradional Chinese Medicine, 100700 Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.forename: Xue-feng
authors.initials: XF
authors.lastname: Feng
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
mesh_terms: D019342:Acetic Acid; D000534:Alum Compounds; D000818:Animals; D002129:Calcium Oxalate / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D003229:Conjunctival Diseases / Q000139:chemically induced*; D003460:Crystallization; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000139:chemically induced*; D006358:Hot Temperature; D030021:Pinellia / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D011817:Rabbits; D027343:Rhizome / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000534:Alum Compounds; D002129:Calcium Oxalate; C041524:aluminum sulfate; D019342:Acetic Acid