[The effects of endothelin and bFGF on proliferation of MC and synergetic effect of insulin].

The effects of basic fibroblast growth factor (bFGF), insulin and endothelin-1 (ET-1) on proliferation of rat glomerular mesangial cells (MC) cultured in vitro and the synergetic effects of insulin and bFGF or ET-1 on MC proliferation were determined by H-TdR incorporation experiment. The results showed that bFGF at concentrations of 5-200 ng/ml and insulin at concentrations of 0.1-2.4 U/ml significantly increased the value of 3H-TdR incorporated into MC (the cpm value). The effect of ET-1 on the cpm value was different at different doses. At concentration ranging from 10(-9) mol/L to 10(-7) mol/L, the cpm value significantly increased with increasing the concentration of ET-1, and the highest value was at concentration of 10(-8) mol/L, However, the cpm value decreased at concentration of 10(-6) mol/L ET-1. When MCs were incubated simultaneously with insulin and bFGF or lower concentration of ET-1 (< 10(-8) mol/L), the cpm value was significantly higher than the sum of that induced independently by insulin and bFGF or ET-1. But the joint effect of insulin and higher concentration of ET-1 (> 10(-7) mol/L) on the cpm value was lower than the sum of that induced separately by insulin and ET-1. It was indicated that bFGF, insulin and ET-1 significantly stimulated MC proliferation; insulin exhibited positive synergetic effect with bFGF or lower concentration of ET-1 on MC proliferation, negative synergetic effect with higher concentration of ET-1 on MC proliferation.