Cyclosporin A suppresses proliferation of renal mesangial cells in culture.

Rat glomerular mesangial cells were isolated and grown in culture for a prolonged period of time. The proliferation of these cells was suppressed by the immunosuppressivum Cyclosporin A (CSA) up to 75%, as measured by the incorporation of radiolabeled thymidine. This was dependent on the concentration of CSA used, being in the range of 125-2000 ng/ml. This effect was specific for CSA and other immunosuppressive derivatives thereof, while a non-immunosuppressive cyclosporin was ineffective. Neither the density of the cultures, nor the time of application had any influence on the susceptibility of the cells to CSA. The suppression of MC proliferation was proliferation was reversible after removal of CSA. These studies demonstrate a suppressive effect of Cyclosporin A on the proliferation of non-lymphocytic cells, the glomerular mesangial cells. This observation may help to explain the beneficial results reported with CSA in the treatment of some kidney diseases.