HIGH DIETARY PROTEIN/ENERGY (P/E) RATIO SPARES TISSUE NITROGEN (N) ASCITES TUMOR-BEARING MICE TREATED WETH ACINETOBACTER GLUTAMINASE-ASPARAGINASE (AGA)

Abstract

Previously, we showed that a high protein (58g%; HP) diet caused marked N sparing of liver (L), intestine (I), thymus (T), and carcass (C) compared to an isocaloric, normal protein diet (20g%; NP) in normal mice treated with AGA (Pediatr Res 17: 192A). In the present study, 32 mice previously innoculated with Ehrlich Ascites tumor were randomized into 2 treatments: AGA (600 IU/kg/d, 7d) and 0.9% NaCl controls and into 2 diets HP or NP. In both diet groups, AGA resulted in markedly lower (p<0.01) tumor burdens as characterized by ascites volume, cell count, or tumor N content, but HP did not increase tumor burden. In the AGA group: HP resulted in significant N sparing in the following tissues (% increase from NP; P value): L (18%; P=0.05), I (25%; p<0.05), T (164%; p<0.01); HP completely prevented the N depleting effect of AGA on L and T; HP resulted in significantly (p< 0.05) higher hematocrit (42%) and serum total protein (5.5 g/dl) compared to NP (33% and 5.0 respectively) but in lower total food intake and insignificant differences in blood counts. Our conclusion may be relevant to man, to other cancers, and to those forms of chemotherapy which affect Nutilization: an increased dietary P/E ratio, even without energy supplementation, may improve N content of T, L, and I without antagonizing anti-cancer therapy. (Support: NIH Grant CA20061)