The protein binding of vinblastine in the serum of normal subjects and patients with Hodgkin's disease.

The protein binding of vinblastine was measured in the serum from 6 normal subjects and 9 patients with Hodgkin's disease. Cellulose acetate electrophoresis showed that the predominant binding protein fractions were the alpha 1- and alpha 2-globulins with little binding to albumin and beta- and gamma-globulins. At a serum concentration of 10 nM a significantly lower percentage bound was found in the patient group (p = 0.001). Binding to both groups was very high at 99.7% bound in the normal subjects and 98.9% bound in the patient group. Binding in both groups was best described by a two class protein binding model with higher and lower affinity binding sites. No significant difference was found on inter-group comparisons of binding parameter values.