Metabolic Clearance and Plasma Half-Disappearance Time of Exogenous Somatostatin in Man

The MCR and half-disappearance time of exogenously administered somatostatin have been measured during and after cessation of a constant infusion. Studies were performed on normal volunteers and patients with chronic liver disease and chronic renal failure. Immunoreactive somatostatin was measured by a sensitive and specific RIA using an antiserum directed against the core of the molecule. Normal subjects had a mean MCR of 1949 ± 250 ml/min (28.4 ± 4.2 ml/min-kg BW) (mean ± sem), similar to values found in five patients with chronic liver disease. However, patients with chronic renal failure showed a highly significant (P < 0.001) lowering of the MCR (501 ± 32.7 ml/min or 7.8 ± 0.6 ml/min-kg). The rate of disappearance of somatostatin after infusion was linear for 7–10 min, after which a much slower component was observed. In normal subjects, the ti/2 of the first component varied from 1.1–3.0 min, in patients with liver disease it varied from 1.2–4.8 min, and in patients with chronic renal failure it var...