Effect of Arginine‐Enriched Total Parenteral Nutrition on the Host‐Tumor Interaction in Cancer‐Bearing Rats

Abstract

By using a transplantable Yoshida sarcoma in a rat total parenteral nutrition model, we measured the effectiveness of an arginine‐enriched amino acid solution (AI‐82) in terms of leucine kinetics and nitrogen balance as indicators of host‐tumor nutrition interaction compared with that of a conventional amino acid solution (Proteamin12). When tumor‐bearing rats received isocaloric total parenteral nutrition solutions for 7 days, AI‐82 significantly improved host nitrogen balance and significantly decreased the tumor‐nitrogen trap throughout the experimental period. Leucine kinetics of whole body and tissues were also determined by a 4‐hour continuous infusion of each total parenteral nutrition solution containing ¹⁴C‐leucine. Significantly increased whole‐body leucine oxidation (p <.01) without an increase in leucine release from normal tissues was observed in the AI‐82 group. Total incorporation of ¹⁴C‐leucine into whole muscle was significantly elevated (p <.05) without changes in muscle protein degradation in the AI‐82 group. In the whole tumor, AI‐82 tended to decrease total incorporation of ¹⁴C‐leucine, but there was no difference in leucine release caused by protein breakdown between the two groups. These findings suggest that AI‐82 can improve the nutritional status of the host over that of the tumor. (Journal of Parenteral and Enteral Nutrition 17:375–383, 1993)