[Course of alcohol concentration in the vascular and extravascular space in the rabbit following subcutaneous implantation of Teflon capsules].

The availability of the interstitial space for pharmacokinetic research work has been an unfulfilled aspiration until today. As a model s.c. implanted Teflon capsules were proposed. It was thought that the fluid, which is excreted some time after implantation into the cavity of the capsules, is comparable to interstitial fluid as to its physical and chemical properties. This paper deals with the experimental elucidation of the question whether the Teflon model can be of importance to research work on ethyl alcohol. The capsules were implanted under the skin of ten rabbits. After 8-10 days the animals were infused with 0.8 g ethanol per kg body weight, and the capsules punctured at regular intervals. The ethanol content of the punctate water was estimated and compared to the arterial blood-water ethanol concentrations. During the first phase after infusion all Teflon estimates lay below the blood-alcohol concentrations; after 60-90 min the concentration-time curves crossed each other so that the maximum of the Teflon-alcohol concentrations followed that of the arterial blood. Afterwards, the courses were nearly parallel, that of the Teflon fluid above the respective blood levels. This type of behaviour is very similar to experimental results on transcellular fluids, such as vitreous-body and synovial fluid. For ethyl alcohol it is thus very questionable whether the Teflon model reflects the interstitial circumstances to a competent degree.