DISTRIBUTION OF APOLIPOPROTEIN-E IN SENILE PLAQUES IN BRAINS WITH ALZHEIMERS-DISEASE - INVESTIGATION WITH THE CONFOCAL LASER SCAN MICROSCOPE

In order to elucidate the mechanism of the occurrence of apolipoprotei n E(ApoE) in senile plaques (SP) in the brain of Alzheimer's disease ( AD) patients, we morphologically examined double immunofluoresent-stai ned sections by scanning with the confocal laser scan microscope (LSM) and reconstructed their three-dimensional structure by a computerized imaging technique. Brain samples were obtained from six pathologicall y diagnosed AD patients, including patients with the genotype ApoE eps ilon 3/3 and epsilon 4/4 ApoE genotype. We found some clear difference s in distribution and shape in the staining patterns of plaque-shaped deposits by ApoE antibody and amyloid beta-protein (A beta) antibody. ApoE deposits were generally larger than A beta deposits in the same r egion and were distributed widely at the periphery of A beta deposits. Several A beta deposits of typical, compact and primitive plaques wer e often included in one diffuse plaque-like deposit of ApoE. Some ApoE deposits did not exhibit any A beta-immunoreactivity. Each core repre sented by ApoE and A beta did not show complete overlap. Typical plaqu es tended to be composed mainly of A beta-immunoreactivity and had lit tle ApoE-immunoreactivity. The discrepancy between ApoE and A beta dep osition may reflect different stages of amyloidogenesis in SP. The pre sence of ApoE alone in plaques may represent the pathological stage be fore the beginning of massive A beta deposition. (C) 1977 Elsevier Sci ence B.V. All rights reserved.