INVESTIGATION OF THE PRESENCE OF APOLIPOPROTEIN-E, GLYCOSAMINOGLYCANS, BASEMENT-MEMBRANE PROTEINS, AND PROTEASE INHIBITORS IN SENILE INTERSTITIAL AMYLOID OF THE PITUITARY

The aim of our study was to test whether local-or organ-limited inters titial amyloid of the pituitary is associated with the presence of gly cosaminoglycans, basement membrane proteins, protease inhibitors, and apolipoprotein E (apo E), as previously observed in other amyloid synd romes. Serial sections from amyloidotic and nonamyloidotic autopsy pit uitaries of patients age 85 yr and over were stained with Congo red, A lcian blue, and, applying immunohistochemistry, with antibodies direct ed against fibronectin, collagen IV, laminin, apo E, alpha(1)-antitryp sin and alpha(1)-antichymotrypsin. Interstitial amyloid was deposited in the immediate vicinity of capillaries and around the acini of the a nterior robe. Glycosaminoglycans were found in capillaries and around the acini of both nonamyloidotic and amyloidotic glands and they were also related spatially to amyloid deposits. Immunostaining of nonamylo idotic and amyloidotic glands demonstrated the presence of fibronectin , collagen IV, and laminin, which was related to basement membranes (f ibronectin, collagen IV, and laminin), interstitium, and serum (fibron ectin only). In amyloidotic glands, each basement membrane protein pre sented with an additional spatial relationship to amyloid deposits. Ap o E was found in amyloidotic cases only within the amyloid deposits. T he results are consistent with the presence of glycosaminoglycans, bas ement membrane proteins, and apo E in local interstitial amyloid depos its of the pituitary, as previously described in other amyloid syndrom es, such as inflammatory related AA-amyloidosis or A beta-amyloidosis related to Alzheimer's disease.