Intestinal uptake of hexoses and fatty acids in tumor-bearing rats

An in vitro technique was used to examine the rate of uptake of varying concentrations of glucose, galactose, and a homologous series of saturated fatty acids into the jejunum of control rats and Noble rats bearing prostatic tumor variants of primary human prostatic adenocarcinoma 52. Both groups of animals were healthy, eating and gaining weight normally. The uptake of acetic and butyric acid was reduced in tumor-bearing rats, but the uptake of four medium chain-length fatty acids was unchanged. The similar value of the incremental change in free energy in the control and tumor-bearing animals indicates similar passive permeability properties of the jejunum in the two groups. The uptake of varying concentrations of glucose and galactose was similar in the control and in the tumor-bearing animals. It is concluded that there are only subtle changes in nutrient uptake in tumor-bearing rats that are eating and gaining weight normally. It is suggested that any alteration in nutrient absorption which might occur in the cachectic tumor-bearing animal is probably due to alterations in food intake or body weight, rather than due to a direct effect of the tumor on the intestine.