[Effect of GMDP encapsulated into liposomes on metastatic spread of Lewis lung carcinoma]

N-acetylglucosaminyl-N-acetylmuramyl-L-alanyl-D-isoglutamine (GMDP), a new liposome-encapsulated muramyl dipeptide analog, was studied for its effect on the Lewis lung carcinoma metastatic spreading as well as on the adenosine deaminase (ADA) and 5'-nucleotidase (5-N) activity in the alveolar and peritoneal mice macrophages. The drug administration was found to cause a sharp dose-dependent decrease in the lung metastases volume and number as compared to those in mice not treated with GMDP. The antimetastatic effect of GMDP is accompanied by an increase in the functional macrophage activity determined by ADA and 5-N level in these cells.