Distribution and biomarker of carbon-14 labeled fullerene C sub(60) ([ super(14)C(U)]C sub(60)) in pregnant and lactating rats and their offspring after maternal intravenous exposure

A comprehensive distribution study was conducted in pregnant and lactating rats exposed to a suspension of uniformly carbon-14 labeled C sub(60) ([ super(14)C(U)]C sub(60)). Rats were administered [ super(14)C(U)]C sub(60) (~0.2mg [ super(14)C(U)]C sub(60) kg super(-1) body weight) or 5% polyvinylpyrrolidone (PVP)-saline vehicle via a single tail vein injection. Pregnant rats were injected on gestation day (GD) 11 (terminated with fetuses after either 24h or 8days), GD15 (terminated after 24h or 4days), or GD18 (terminated after 24h). Lactating rats were injected on postnatal day 8 and terminated after 24h, 3 or 11days. The distribution of radioactivity in pregnant dams was influenced by both the state of pregnancy and time of termination after exposure. The percentage of recovered radioactivity in pregnant and lactating rats was highest in the liver and lungs. Radioactivity was quantitated in over 20 tissues. Radioactivity was found in the placenta and in fetuses of pregnant dams, and in the milk of lactating rats and in pups. Elimination of radioactivity was < 2% in urine and feces at each time point. Radioactivity remained in blood circulation up to 11days after [ super(14)C(U)]C sub(60) exposure. Biomarkers of inflammation, cardiovascular injury and oxidative stress were measured to study the biological impacts of [ super(14)C(U)]C sub(60) exposure. Oxidative stress was elevated in female pups of exposed dams. Metabolomics analysis of urine showed that [ super(14)C(U)]C sub(60) exposure to pregnant rats impacted the pathways of vitamin B, regulation of lipid and sugar metabolism and aminoacyl-tRNA biosynthesis. This study demonstrated that [ super(14)C(U)]C sub(60) crosses the placenta at all stages of pregnancy examined, and is transferred to pups via milk. In an investigation of the distribution of radioactivity after administration of [ super(14)C(U)]C sub(60) (a 5% PVP-saline suspension) in pregnant and lactating rats after a single tail vein injection, biomarkers of inflammation, cardiovascular injury and oxidative stress were measured. The goals of the investigation were to provide a basic understanding of the distribution, elimination, biological impact and distribution of radioactivity in exposed adult rats, and in their fetuses and pups.