Chromaffin cells express Alzheimer amyloid precursor protein in the same manner as brain cells

Amyloid precursor protein (APP) 695 is remarkably expressed in the brain as compared with APP751 and APP770 which are dominant in other tissues. This study showed that human and bovine adrenal medullae dominantly expressed mRNA of APP695 as do brain nerve cells, while the adrenal cortexes expressed mRNAs of APP751 and APP770 as in other non-neural tissues. In immunohistochemistry, chromaffin cells of young rat adrenal medullae and primary cultured bovine chromaffin cells were significantly stained with a monoclonal antibody (mAb) against the common domain of the amino-terminal side of human APPs. At higher magnification, the immunostained cells revealed that APP was granularly distributed not only in the perikaryon but also in the cell processes. These results suggest that primary cultured chromaffin cells representing the state of adrenal medulla in vivo are a useful model for studying the pathophysiological functions of APPs and the mechanism of processing of APPs as a model of neuronal systems.