Distribution, metabolism, and excretion of [14C] glutaraldehyde

Radiolabeled glutaraldehyde (GA) was infused into rats in order to determine its distribution between cellular and humoral fractions of the blood, its potential metabolism by RBC's, its rate of excretion, and the nature of its urinary products. This study demonstrated that [14C]GA was distributed between the RBC's and plasma at a ratio greater than 1. Although the absolute counts of both fractions dropped 80% over 3 days, the percentage bound or incorporated increased over time. Despite the extensive uptake by RBC's these cells were unable to metabolize GA to CO2. Urinary excretion of the radiolabel was rapid; the predominant form in the urine was less than 1 kDa in size. All evidence suggested that it was not native GA. We conclude that the RBC's can incorporate GA, but can not metabolize it completely to CO2. Nevertheless, much of the infused GA was rapidly converted to nonreactive metabolites and eliminated by the kidney.