Demonstration of a Specific Transport Protein for Cardiac Glycosides in Bovine Blood^a

A Specific Binding Protein for Cardiac Glycosides Exists in Bovine Serum

“…Antibodies against a Cardiac Glycoside-binding Protein-In preliminary experiments, we were able to demonstrate the existence of a minor protein in the globulin fraction of bovine serum that was labeled specifically by the protein-reactive digoxigenin derivative HDMA (26) (Fig. 1).…”

“…Impure fractions of CGBG were essentially prepared as described earlier (26). Briefly, the bovine serum globulin fraction was given at pH 8.0 to a CM-Sephadex C50 column.…”

“…This finding encouraged us to investigate the possibility that mammals may have a specific cardiotonic steroid-binding globulin (CGBG) 1 in their blood plasma, and the present paper reports evidence in support of this. A preliminary report has been given (26).…”

The digitalis-like steroid hormones: New mechanisms of action and biological significance

“…Hydroxylation by cytochrome P450 (CYP) enzymes and conjugation with glucuronide and sulfate are among the major hepatic pathways of steroid inactivation (Guengerich, 1989;Tukey and Strassburg, 2000). Like other steroid hormones, DLC bind to specific plasma proteins, as was first demonstrated in toad (Lichtstein et al, 1993a) and later in bovine (Antolovic et al, 1997) and human (Komiyama et al, 1998) …”