The effect of streptozotocin-induced diabetes mellitus on the ability of rat serum to stimulate human fibroblast proliferation.

Abstract

Impaired tissue repair, tumor growth, and diminished uterine response to β-estradiol are characteristics of experimental diabetes mellitus; this may be due to a specific defect in cellular proliferation. The aim of this study was to determine whether circulating growth factors other than the somatomedins are deficient in diabetic rat serum. We examined the effect of streptozotocin-induced diabetes mellitus on the ability of rat serum to stimulate the growth of cultured human diploid skin fibroblasts, a cell line that has been shown to proliferate in somatomedin-depleted serum. Normal rat serum resulted in a dose-dependent increase in the number of human skin fibroblasts [HES; 2.78 ± 0.15 × 105 (±SEM) for 5% serum vs. 0.21 ± 0.02 ± 105 for no serum; P < 0.0005]. In contrast, serum from untreated diabetic rats resulted in significantly less proliferation than normal serum (0.35 ± 0.01 × 105 vs. 2.78 ± 0.15 × 105; P < 0.0005 for 5% diabetic and normal rat serum, respectively). Similarly, serum from untreated...