FUNDAMENTAL AND CLINICAL INVESTIGATION ON THE BINDING-PROTEIN TO INDOCYANINE GREEN

Abstract

The binding of Indocyanine Green (ICG) with serum proteins and rat liver supernatant was investigated by Gel-filtration using Sephadex G-200.
By investigating the binding of various amounts of ICG, it was found that, in low concentration, it bound with high molecular proteins, but, in high concentration, with low molecular proteins.
By examining the chromatographic patterns, the amount (mg; mg/g of protein) of ICG binding to each peak was calculated from samples of various liver diseases and from normal subjects. It was revealed that ICG significantly increased (p<0.05) in peak III in cases of acute hepatitis, chronic hepatitis and liver cirrhosis, while in peak II ICG was significantly decreased (p<0.025) in cases of chronic hepatitis.
In the investigation of ICG binding to rat liver supernatant, ICG bound more to the Y protein than the X protein under low concentration (3.7mg/dl of supernatant), which was close to the initial concentration of the clinical ICG test. From these results it was presumed that the role of the Y protein was clinically more important than either the X or Z protein.
Chromatographically, when a patient's serum (ICG-highly abnormal; BSP-normal) containing ICG was added to the rat liver supernatant, the transport of ICG was similar to the normal control. It is suggested that the abnormality of ICG binding to serum protein is not the cause of ICG abnormal retention phenomenon.