The localization of amyloid beta protein (A beta), A beta 40, A beta 4
2, and transthyretin (TTR) was investigated immunohistochemically in t
he autopsied human kidney, using polyclonal antibodies against TTR, A
beta and C-terminal end-specific antibodies against A beta 40 and 42.
Immunoreactivities of A beta and A beta 40 were found both in the prox
imal and distal tubular epithelial cells. But the immunolocalization o
f A beta 40 was observed predominantly in the distal tubules whereas t
hat of A beta 42 was predominantly recognized in the proximal tubules.
TTR, sequestrating protein for A beta, was present in the proximal tu
bules. The mechanism by which A beta does not form amyloid in Alzheime
r's disease outside the brain remains unknown. The tubular epithelial
cells in the kidney may provide a useful system to shed light on this
issue. (C) 1997 Elsevier Science Ireland Ltd.