Pharmacokinetic study of PAF-acether. Preliminary results after the intravenous administration of a 3H-labelled product to the rabbit.

3H-PAF-acether was rapidly distributed and deacetylated to 3H-lyso-PAF-acether after its intravenous administration to the rabbit. Within 30 min, an equilibrium was established between PAF-acether (10%) and lyso-PAF-acether (90%). A pharmacokinetic study and a preliminary metabolic evaluation were carried out in three rabbits, after the intravenous administration of 3H-labelled PAF-acether (40 Ci/mM, CEA, Saclay, France). This work required the development of a method for the separation of the unchanged product from its potential plasma metabolites, particularly from lysoPAF which appears to be the only early degradation product.