RESUMO
<p><b>OBJECTIVE</b>To investigate the substance basis and the mechanism of pseudoanaphylactoid reactions (PR) induced by Shuanghuanglian injection (SHLI).</p><p><b>METHOD</b>(1)The study of PR and the substance basis of PR of SHLI: ICR mice were divided into different test groups, the mice were intravenously injected with solutions of different concentration of SHLI, baicalin, forsythin, caffeotannic acid, positive control Compound 48/80 and normal sodium. All test substances were mixed with 0.4% Evans blue. The reaction and vascular permeability of the ears were observed and measured 30 min after SHLI injection. (2) The study of mechanisms: Mice were pretreated with an oral administration of Astemizol, intraperitoneal injection of cyclophosphamide 75 mg x kg(-1) or Compound 48/80 4 mg x kg(-1), then mice were intravenously injected with SHLI. At last, vascular permeability of the ears in pretreated groups was compared with SHLI treatment alone group.</p><p><b>RESULT</b>SHLI of 300 mg x kg(-1) and 600 mg x kg(-1) caused obvious vascular hyperpermeability, but baicalin, forsythin and caffeotannic didn't cause vascular hyperpermeability in the ears. The Astemizol can decrease the degree of SHLI-induced vascular hyperpermeability of the ears in the mice. After intraperitoneal injected with cyclophosphamide, there was a slight decrease in the degree of SHLI-induced vascular hyperpermeability, but there was no marked changes in the degree of the SHLI-induced vascular hyperpermeability after the mice were pretreated with Compound 48/80.</p><p><b>CONCLUSION</b>SHLI in clinic equivalent dose can cause vascular hyperpermeability. Baicalin, forsythin and caffeotannic may not result in the PR of SHLI. The mechanism of the PR maybe relate to that SHLI stimulates histamine release, the activation of leucocyte maybe take part in the SHLI-induced PR, too. Antihistamine drug can prevent the genesis of PR which induced by SHLI.</p>