Growth of rabbit aortic smooth muscle cells in serum from patients with juvenile diabetes.

The effect of human diabetic serum on the growth of rabbit arterial smooth muscle cell cultures was studied in the stationary phase of growth. The serum was obtained from young, male, non-obese, juvenile diabetics and non-diabetics. The experiments were carried out using dialysed as well as non-dialysed serum. The concentration of cholesterol and triglycerides were equal in normal and diabetic serum. Media supplemented with diabetic serum from both short term and long term diabetics stimulated the outgrowth of the smooth muscle cells significantly (2p less than 0.01). A statistically significantly stimulation of growth was also observed using dialysed human diabetic serum (2p less than 0.05). Autoradiographic studies showed that the number of 3H-thymidine labelled cells and of cells in mitosis increased appreciably after incubation in diabetic human serum (2p less than 0.005). The present data show that human serum from juvenile diabetics contains a factor or factors which promote an excessive growth of arterial medial cells. The factor(s) is not lipids as hyperlipemia was not present nor is it glucose, aminoacids, fructose or ketones, as the growth effect remained after dialysis.