DNA-synthesis-stimulating activity in the sera of anorexia nervosa.

Serum factors which stimulate DNA synthesis were investigated in patients with anorexia nervosa. The factors were assayed by examining [3H]-thymidine incorporation into the nuclei of human fibroblasts in culture using autoradiography. The mean percentage of labeled nuclei (labeling index) induced by serum was significantly lower (p < 0.005) in 5 patients with anorexia nervosa (21.0 +/- 5.9 percent, mean +/- S.D.) than in 5 normal adult subjects (33.9 +/- 3.3 percent). Two of the patients with anorexia nervosa were treated with intravenous hyperalimentation (IVH). In one of the IVH treated patients, the labeling index increased from 17.4 to 32.8 percent at the 6th week of treatment, and in the other increased from 19.4 to 29.8 percent at the 4th week. In both patients, body weight increased by 1.5 to 2 kg. IVH in these patients increased DNA-synthesis-stimulating activity.