Effects of ethyl N-N-benzyl-methyl-oxamate in Meriones unguiculatus infected with Echinococcus multilocularis metacestodes. Biochemical and ultrastructural observations.

Ethyl N-N-benzyl-methyl-oxamate is a N-substituted derivative of the oxamic acid, well-known as inhibitor of the lactate dehydrogenase activity. The biochemical and ultrastructural effects of this drug in Echinococcus multilocularis metacestodes and the repercussions in the livers of receptive host, Meriones unguiculatus, were investigated. This compound decreased the specific activity of the lactate dehydrogenase in the metacestodes and the host liver by 81 and 86.8%, respectively. This N-methyl compound has shown an important repercussion on the lactate dehydrogenase activity due to its greater lipophilicity and thus allows a better penetration of the molecule. In the host liver, a fall of the alkaline and acid phosphatases activity was observed. The glucose and glycogen concentrations were also decreased. The ultrastructural study provided an alteration of the tegument of the metacestodes and damages of the muscular system. The parenchyma was disorganized. In conclusion, these biochemical and ultrastructural data obtained with ethyl-N-N-benzyl-methyl oxamate in E. multilocularis metacestodes show clearly the importance of the lactate dehydrogenase activity in the metacestodes.