No abstract

Adequate parenteral nutritional support improves nutritional status in cancer patients, but its effect on tumor growth remains controversial. Using a transplantable mammary adenocarcinoma in a rat-TPN model, the relative effect of different exogenous intravenous nutrients on tumor growth and host maintenance was studied. Relative to chow controls, starvation increased host depletion without reducing tumor growth. Adequate carbohydrate calories alone neither improved host maintenance nor stimulated tumor growth, yet adequate amino acids alone did improve host maintenance but also stimulated tumor growth. Adequate amino acids and carbohydrates given simultaneously maximized both host maintenance and tumor growth. In contrast, an isocaloric, isonitrogenous, intravenous diet providing non-nitrogenous calories as fat promoted host maintenance equivalent to carbohydrate-based TPN with no tumor stimulation. This apparent differential utilization of fat calories by normal and malignant cells may permit manipulation of the relative benefit of parenteral nutrition to host or to tumor, permitting host repletion without tumor stimulation or alternatively tumor stimulation at appropriate times to increase sensitivity to phase-specific antineoplastic therapy.

No abstract

To investigate the effect of stress on the dynamics of serum protein response during starvation, serum albumin, prealbumin, and transferrin changes were studied in six chair-adapted macaques during two separate 7-day test periods: (1) Starvation--NPO + IV D5/W (100 cc/kg/day), and (2) Surgery/starvation--laparotomy and gastrostomy + NPO + IV D5/W (100 cc/kg/day). During the starvation period, transferrin was the only protein that decreased from baseline values and did so at day 7 of the study period. In contrast, during the period of starvation following surgery, both prealbumin and transferrin were significantly decreased at both day 4 and day 7 of the study period, whereas albumin was only decreased at day 7 of this period. These findings indicate that the addition of a surgical stress to starvation results in a depression of serum protein levels that is not only of greater magnitude, but also more rapid in onset than observed with starvation alone. In addition, the differential response of prealbumin and transferrin to starvation and stress may provide a useful indicator of the presence and/or degree of stress in certain situations. The clinical utility of this finding remains to be ascertained.

No abstract