BOLESATINE INDUCES AGGLUTINATION OF RAT PLATELETS AND HUMAN ERYTHROCYTES AND PLATELETS IN-VITRO

Bolesatine is a toxic glycoprotein isolated from the mushroom Boletus satanas Lent, which has been shown to inhibit protein synthesis in cel l-free systems and cell culture. It is toxic to rodents, the LD(50)% 2 4 h being 1 mg kg(-1) (i.p.) and 0.15 mg kg(-1) (i.v) in the rat in wh ich it induces hepatic blood stasis. Bolesatine possesses lectinic pro perties with in particular a sugar binding site for D-galactose and mi togenic activity toward lymphocytes. Tested for cell agglutination on red blood cells and platelets, bolesatine agglutinates both human and rat platelets from threshold concentrations of 30 and 300 nM respectiv ely. EDTA and PGI(2) (aggregation inhibitors) do not decrease agglutin ation induced by bolesatine, indicating that the process does not invo lve platelet activation. In contrast, fibrinogen decreases platelet ag glutination induced by bolesatine, most likely by masking the binding sites on platelets or by interacting with the toxin. Bolesatine agglut inates all red blood cells without any blood group specificity in the concentration range of 20 to 40 nM. This haemagglutination cannot be p revented by sugars, including D-galactose at a concentration of 0.5 M.