Lymphoid tissue responses to emulsified perfluorochemicals: comparative aspects

Retention of perfluorochemicals in rat liver and spleen

The uptake and retention of perfluorochemicals (PFCs) into rat liver and spleen have been measured for up to 28 d following injection of either the commercial PFC emulsion, Fluosol, or a novel perfluorodecalin (FDC)-based emulsion. Both quantitative and qualitative differences in the retention of individual PFCs were observed, depending on composition of emulsion administered. Nevertheless, uptake of PFCs into the spleen was consistently greater than into the liver, irrespective of formulation injected.

Lymphoid tissue responses to concentrated perfluorochemical emulsions in rats

The effects of injecting perfluorochemical (PFC) emulsions of varying concentrations on lymphoid tissues have been studied in rats. Tissue weights were increased in proportion with quantity of PFC injected, with spleen responses consistently greater than those of the liver. PFC droplets recovered from tissues had mean diameters in the 1-10 microns range, with those from the spleen being larger than from the liver. Recovered droplet diameters were considerably greater than freshly-prepared emulsion mean particle sizes (0.20-0.25 microns). This suggests that coalescence of emulsion droplets following accumulation in tissues is a pre-requisite to the eventual excretion of PFC vapour through the lungs.

Effects of emulsified perfluorochemicals on liver aryl esterase in rats

1. The effects of intravenous (i.v.) injection of various perfluorochemical (PFC) emulsions have been studied separately in male and female rats. 2. Injection of 10 ml/kg body weight of either Fluosol-DA 20% (F-DA) or a novel perfluorodecalin emulsion containing a C-16 oil additive in male rats increased liver weight up to 7 days later; no corresponding change occurred in response to injection of Oxypherol (FC-43). 3. Liver weight was also increased in female rats at 72 hr after injection of the novel emulsion but this was less pronounced than in males; liver weight in female rats was unchanged in response to injection of either F-DA or FC-43. 4. Mean liver aryl esterase activity in male rats was increased 2- to 3-fold (P less than 0.05) at 7 days after injection of the novel emulsion. No significant alterations in aryl esterase activity occurred in response to injection of either F-DA or FC-43, although in both cases there was a trend towards increased activity. 5. Liver aryl esterase activity in female rats was significantly (P less than 0.05) decreased at 72 hr following FC-43 injection with similar, but much less pronounced, changes occurring in response to injection of F-DA and the novel emulsion. 6. These results show that injection of a single low dose of emulsified PFCs into rats can alter hepatic microsomal aryl esterase activity but the response is highly variable, depending on composition of emulsion injected and sex of recipient.

Oxygen-transport fluid based on perfluorochemicals: effects on liver biochemistry

The effects of (1) i.v. injection of various perfluorochemical (PFC) emulsions, (2) different fractions of the non-ionic poloxamer surfactant, Pluronic F-68, or (3) i.p. injection of component PFC oils have been studied separately in male and female rats. Injection of 10 ml/kg body wt of either Fluosol-DA 20% (F-DA) or a novel perfluorodecalin emulsion containing a C-16 oil additive in male rats increased liver weight up to 7 days later; no corresponding effect occurred in response to injection of Oxypherol (FC-43). Liver weight was also increased in female rats at 72 hr after injection of the novel emulsion but this was less pronounced than in males; liver weight in female rats was unchanged in response to injection of either F-DA or FC-43 but was 12% greater at 72 hr after injection of FDC oil. Mean liver microsomal cytochromes P-450 concentrations in male rats were increased 2-3 fold at 72 hr after injection of either FDC, F-DA or the novel emulsion; a less pronounced increase was also seen at 7 days in animals receiving the novel emulsion. No significant alterations in cytochromes activity occurred in response to injection of FTPA, FTBA, the C-16 oil, FC-43 or either commercial grade or purified pluronic solution. Liver cytochromes P-450 concentrations in female rats were unaffected by any of the experimental treatments.

Effects of emulsified perfluorochemicals on liver cytochromes P-450 in rats

1. The effects of intravenous (i.v.) injection of various perfluorochemical (PFC) emulsions or different fractions of the non-ionic poloxamer surfactant, Pluronic F-68, have been studied separately in male and female rats. 2. Injection of 10 ml/kg body wt of either Fluosol-DA 20% (F-DA) or a novel perfluorodecalin emulsion containing a C-16 oil additive in male rats increased liver weight up to 7 days later; no corresponding effect occurred in response to injection of Oxypherol (FC-43). 3. Liver weight was also increased in female rats at 72 hr after injection of the novel emulsion but this was less pronounced than in males; liver weight in female rats was unchanged in response to injection of either F-DA or FC-43. 4. Mean liver microsomal cytochromes P-450 concentrations in male rats were increased 2-3 fold at 72 hr after injection of either F-DA or the novel emulsion with a less pronounced increase also seen at 7 days in animals receiving the novel emulsion. No significant alterations in cytochrome concentration occurred in response to injection of FC-43 or either commercial grade or purified pluronic solution. 5. Liver cytochromes P-450 concentrations in female rats were unaffected by any of the experimental treatments. 6. These results show that injection of a single low dose of emulsified PFCs into male rats can increase hepatic microsomal cytochromes P-450 concentration but the response is highly variable, depending on composition of emulsion injected.

Effects of a novel perfluorochemical emulsion on lymphoid tissues and immunocompetence in rats: time course effects relative to immunological challenge

1. The effects of intravenous (i.v.) injection of low doses of a novel perfluorochemical (PFC) emulsion on lymphoid tissues and antibody production against i.v.-injected sheep red blood cells (SRBC) have been studied relative to the timing of immunization in rats. 2. Spleen and, to a lesser extent, liver weights were significantly increased in response to injection of emulsion but no consistent pattern was observed. 3. Thymus weight was consistently decreased following injection of emulsion; in contrast, mesenteric lymph node (MLN) weights were unchanged throughout except for a significant increase in animals injected with emulsion 24 hr prior to immunization. 4. The mean plasma antibody titre to SRBC showed a variable response in animals receiving the emulsion: titres were significantly increased in rats injected with emulsion 1 hr prior to immunization whereas they were significantly reduced in animals injected with emulsion 7 days before SRBC. 5. These results show that lymphoid tissue weights and plasma antibody titres to SRBC vary according to the time of a previous or subsequent injection of PFC emulsion.