Distribution, molecular forms, and bioactivity of immunoreactive gastrin in a patient with metastatic gastrinoma

A patient with metastatic gastrinoma whose plasma gastrin ranged from 7.6 nmol X ml-1 at presentation to 18.9 nmol X ml-1 just before death 4 yr later has been studied. The presence of such high circulating levels facilitated study of the biological and immunological activities as well as the molecular forms of gastrin in plasma, ascitic fluid, urine and cerebrospinal fluid. The results indicate: 1) the 34 amino acid gastrin (G34) was the only molecular form detectable in the body fluids studied; 2) bioactivity of G34 is maintained despite passage across the renal endothelium and the blood brain barrier; 3) the blood brain barrier significantly limits diffusion of G34.