UPTAKE AND TRANSPORT OF IMPOSIL BY GLOMERULAR MESANGIUM IN MOUSE

Abstract

The mesangial uptake and transport of particulate material was studied using an iron-dextran complex, Imposil, as a tracer particle. The tracer was given as a single dose into the tail vein of the mouse and animals were killed at intervals from 5 min to 48 h. Light microscopy and EM showed that the iron-dextran complex was initially taken into the matrix channels of the mesangium from which it progressed over the course of 8 h to the matrix of the juxtaglomerular apparatus and intercellular spaces of the macula densa. This delineated a continuous functional pathway from the glomerular capillary lumen to the macula densa cells of the distal tubule for material taken up by the mesangium. The products of inflammatory lesions in the glomerulus may affect the secretory function of the granular cells of the juxtaglomerular apparatus as it appears that such products must circulate in the immediate environment of these cells.