Glomerular basement membrane: lamina rara, lamina densa.

Electron immunohistochemical and histochemical studies of glomerular and tubular basement membranes were undertaken to elucidate the relationship between lamina rara and lamina densa. Our results indicate that the lamina rara is not a fixation artifact and it has common antigenic determinants with lamina densa (type IV collagen antigens). Therefore, lamina rara has to be considered an integral component of basement membranes, and biochemical preparations containing only lamina densa should not be considered representative of the whole basement membrane.