Ultrastructural localization of three major basement membrane components--type IV collagen, heparan sulfate proteoglycan and laminin in the normal human GBM

Abstract

Human glomerular basement membrane (GBM) is known to contain type IV collagen, heparan sulfate proteoglycan (HS-PG) and laminin in the extracellular matrix. In this study, ultrastructural distribution of these antigens was investigated in normal human glomeruli using the immunogold technique. Type IV collagen was present throughout the GBM, mainly on the lamina densa, and all over the mesangial region. HS-PG was present on the laminae rarae, predominantly on the lamina rara externa, and periphery of the mesangial region. Laminin was present throughout the GBM and peripheral region of the mesangial matrix. Our study demonstrated the preferential localization of each component in the GBM.