Long-term observation of PFC storage in organs of rats after various dosages.

The study reports long term observations concerning the proliferation of connective tissue and histological changes in the liver, spleen and lung of Wistar rats after intravenous injection of fluorocarbons (Fluosol-DA 20% and 35%). No elevated connective tissue values were observed after a single injection of 2.3-3.1 g fluorocarbons per kg body weight with F-DA 20% or 4.1-5.1 g/kg body weight with F-DA 35% at determination of the stroma using the hydroxyproline method. After repeated intravenous injections of F-DA 20% (up to 22 g fluorocarbons/kg body weight) and F-DA 35% (up to 31 g/kg body weight), elevated levels of hydroxyproline were found in the liver as proof of proliferation of connective tissue. When F-DA 20% was injected, normal levels of hydroxyproline were found even after one year. In neither case were quantitative changes in the connective tissue of the lungs observed. Representative results for the spleen could not be reported because of methodological reasons. Histological changes were demonstrated and discussed. Since the given doses of F-DA 35% were significantly higher than those normally used, we can assume that the connective tissue proliferation occurs only after a very high limit is exceeded.