Evidences for the phagocytic activity of cultured rat mesangial cells

Abstract

It is known that glomerular mesangial cells have two major functions; the control of glomerular blood flow by contraction and the removal of macromolecules from the mesangial region by the endocytosis. As regards the latter function, the evidence of phagocytic activity for particulate materials is controversial. In this study, we attempted to make it clear whether mesangial cells isolated from glomeruli exhibit phagocytic activity in vitro.Male Sprague-Dawley rats, 6-8 wk old, were used. Glomeruli were isolated from rat renal cortex by the sieving technique according to Morita. The isolated glomeruli were cultured at 37°C in an atmosphere of 95% air, 5% CO2 in a medium containing 5ml of RPMI-1640 with 20% decomplemented fetal calf serum, and subcultured. Mesangial cells purified at the 6-20th succesive cultivations were identified by their morphology and antigenic phenotypes which were analyzed by immunohistochemical method using anti Thy-1, anti Ia, anti leukocyte common(LC) antigen, anti iC3bR, and Mar(anti rat macrophage antigen) 1-4 monoclonal antibodies. Fc receptor was detected with rosette forming method using sheep blood cells(SRBC).