Effect of histamine and glucose on encystation of Entamoeba histolytica in vitro.

Isolates of Entamoeba histolytica grown and maintained in modified Boeck and Drbohlav's medium were used to examine the effect of histamine and glucose on encystation process in vitro. This revealed that 60-74% of the active and motile trophozoites of E. histolytica encysted within 72 hours in the presence of histamine and glucose, in contrast to 10-20% encystment in controls (with out histamine and glucose); a highly significant difference (P < 0.001). These observations also suggest the possibility of active role of histamine and glucose in encystation of E.histolytica in vivo.