Effect of growth factors present in serum on insulin resistance and endothelial dysfunction in endothelial cells

Abstract

Insulin Resistance is a pathophysiological function of Type II Diabetes Mellitus which can be comprehended by quantifying the parameters critical in the insulin signaling pathway. Serum has a profound role in evaluating cellular growth and metabolism in vitro. The growth factors present in serum such as IGF, EGF, FGF affects the regulatory components of insulin signaling pathway that leads to insulin resistance. This study explores the effect of growth factors present in Fetal Bovine Serum (FBS) in insulin signaling and endothelium regulation in endothelial cells (Ea. hyp926). The dose-dependent and time-dependent treatment of FBS on the cells displayed changes that were detected by MTT and 2-NBDG assays for assessing cell viability and glucose uptake. Spectrophotometric analysis of nitric oxide (NO) and lactate dehydrogenase (LDH) determined vascular homeostasis and no cytotoxic effects of serum, respectively, in endothelial cells. These findings indicate that FBS at higher levels could possibly lead to loss of NO activity which in turn could impair endothelium-mediated dilation. The inhibition of enzymatic activity of eNOS may activate the release of LDH in endothelial cells. In conclusion, our findings indicate a specific concentration of serum enhances insulin signaling and endothelium cell regulation by modulating glucose uptake and NO production.