Localization of Amyloid SAA Gene Expression in Mouse Liver by in Situ Hybridization

Abstract

The recognition of serum amyloid A protein (SAA: the putative precursor of reactive amyloid fibril protein AA) as an acute phase reactant made it possible for us predictably to induce its synthesis under experimental conditions (1, 2). This together with the immunoradioassay and other biochemical methodologies that serve as tools to monitor the fluctuation of the SAA levels in a precise manner has contributed greatly to the definition of the cellular and molecular synthesis of SAA, one of the key factors in amyloidogenesis (1, 3–5). Recently, the molecular biological technology has further advanced our understanding of the hepatic and extrahepatic synthesis of SAA (6–12). Because these technologies primarily assay homogenates of tissues which consist of heterogenous cell populations, individual cell types that participate in SAA synthesis have not yet been clearly defined, with possible exception of hepatocytes that have been considered to be a major source of SAA.