The nature of big plasma somatostatin: Implications for the measurement of somatostatin-like immunoreactivity in human plasma

✍ Scribed by J.Michael Conlon; Myrtle Bridgeman; K.George M.M. Alberti

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 747 KB
• Volume: 125
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(82)90002-1

✦ Synopsis

Big plasma somatostatin (BPS) represents an artifact of measurement. High-molecularweight globulins (CY, 8, and y) in human plasma inhibit, in a concentration-dependent manner, the binding of radiolabeled somatostatin analogs to antibody directed against somatostatin. The magnitude of inhibition varies with antibody and plasma sample and is greatest for the cu-globulin fraction. The mechanism of inhibition involves binding of plasma globulins to antibody, thereby blocking tracer-binding sites, and does not involve inhibition by somatostatin bound noncovalently to plasma proteins or tracer degradation. Thus BPS arises from a property of plasma rather than of somatostatin and so it is suggested that this mechanism may account for the presence of other "big" forms of hormones in plasma.