IMMUNOHISTOCHEMICAL STUDY ON THE DEPOSITION OF APOLIPOPROTEIN-E IN CEREBRAL AND ISLET AMYLOIDOSES IN CYNOMOLGUS MONKEYS (MACACA-FASCICULARIS)

To investigate the role of apolipoprotein E (ape E) in amyloidoses of cynomolgus monkeys, the localization of apo E in cerebral amyloid, inc luding senile plaques and cerebrovascular amyloid, and in islet amyloi d was examined immunohistochemically. Mature types of senile plaques w ith amyloid deposits and cerebrovascular amyloid showed intense immuno reactivity to both antisera to apo E and amyloid beta protein (A beta) . In contrast, diffuse plaques without obvious Congophilic amyloid sho wed weak immunoreactivity to antiserum to apo E, but intense reactivit y to antiserum to A beta. In addition, the number of these apo E-posit ive diffuse plaques was small compared with that of A beta-positive pl aques. On the other hand, diabetic islet amyloid that was negative wit h A beta, reacted intensely with antiserum to apo E. These findings su ggest that apo E plays an important role in amyloid fibril formation i n several types of amyloidoses.