Table 2.

Serum and Liver PFOS Concentration

	SD	SD +PFOS	H-SD	H-SD +PFOS	HFD	HFD +PFOS
Serum (μg/mL)	<LLOQ	40.0 ± 6.9	<LLOQ	34.8 ± 6.1 ¶	<LLOQ	42.4 ± 2.0
Liver PFOS (μg PFOS/g tissue)	<LLOQ	200.2 ± 22.5	<LLOQ	148.0 ± 16.1 *	<LLOQ	137.0 ± 32.8 *
Total Liver PFOS (μg PFOS)		363.5 ± 20.2		272.7 ± 18.0 *¶		354.1 ± 38.4
Liver/Serum Ratio		5.2 ± 0.33		4.4 ± 0.44		3.3 ± 0.34 *
Serum PFOS (mg PFOS/mL per mg of PFOS consumed)		2.32 ± 0.14		2.19 ± 0.14 ¶		6.01 ± 0.13 *
Liver PFOS (mg PFOS/g tissue per mg of PFOS consumed)		11.6 ± 0.5		9.3 ± 0.4 ¶		19.4 ± 2.1 *

Male C57BL/6N mice were fed either control standard chow diet (SD) or a 60% kCal high fat diet (HFD).After 4 weeks, half of HFD mice were switched to a SD (H-SD) to induce weight loss, and mice were further divided with a subset having 0.0003% PFOS in diet. Mice were kept on study for an additional 10 weeks. PFOS was extracted from liver and serum and quantified using LC-MS/MS. All mice that were not dosed with PFOS had concentrations below the lower limit of quantification (LLOQ, 15 ng/mL, 3 μg/g tissue).Total liver PFOS was calculated by multiplying concentration by total liver weights and PFOS concentrations were also normalized to average food consumption within each diet group. The HFD and H-SD mice had a lower liver PFOS concentration, and the H-SD mice had less overall liver PFOS. The HFD mice had a higher liver and serum PFOS concentration relative to the amount of PFOS consumed within the diet. Calculations were performed using a one-way ANOVA followed by Fisher’s LSD test. All values are means ± SD; N=5–8.

^*indicates p<0.05 versus SD+PFOS

^¶indicates p<0.05 for H-SD+PFOS versus HFD+PFOS.