Synthesis of angiotensinogen by renin-containing neuroblastomas

Angiotensinogen in plasma is of hepatic origin, but many organs possess the ability to synthesize this protein because messenger RNA for angiotensinogen is widely distributed in the body. The cell types responsible for the extrahepatic synthesis of angiotensinogen remain to be identified. To examine whether renin-containing cells synthesize angiotensinogen, we have utilized a polyclonal antibody to angiotensinogen and immunoprecipitated metabolically labeled cells of two neuroblastomas known to contain renin. The results indicate that the cell line Neuro 2a synthesizes and releases a protein with a molecular mass of 57 kDa that is specifically recognized by the angiotensinogen antibody, indicating that Neuro 2a synthesizes angiotensinogen. Similarly, the cell line NB41A3 was also found to synthesize a protein specifically recognized by the antibody to angiotensinogen.