抄録
The localization of apo A-IV was examined in several organs of rats using an immunohistochemical technique. It is well known that rat apo A-IV is synthesized in the small intestine and in the liver. However, the catabolic site of apo A-IV has not been fully understood. In the present study, apo A-IV was positive in the epithelium of the small intestine, liver cells, and renal proximal tubular cells, and was negative in the large intestine. Apo A-IV was localized in villus epithelium both in the jejunum and ileum, and the intensity of staining for apo A-IV was greater in jejunum than ileum. The stained liver cells were scattered around the central vein. The positive findings both in the small intestine and the liver are compatible with the fact that these organs are responsible for the synthesis of apo A-IV. On the other hand, apo A-IV was also detected in renal proximal tubular cells when glomerulus was not stained.
Since it is considered that apo A-IV is not synthesized in the kidney, it is feasible that apo A-IV in the plasma passes through the glomerulus, and is then taken up by tubular cells as well as other lowmolecular-weight proteins.
