Figure 4.

Metabolism of gavaged all-trans–retinaldehyde in RDH11 knockout (KO) mice versus wildtype (WT) littermates. Retinaldehyde (30 mg/kg body weight in corn oil:ethanol (85:15) was administered by gavage. Retinoids were extracted from serum collected at the indicated time points after gavage and analyzed by reversed-phase HPLC. Zero time point values reflect baseline retinoid levels after administration of vehicle. A–C, several animals were analyzed at 0-, 60-, and 240-min time points: KO males, n = 10, WT males, n = 6; KO females, n = 4–16, WT females, n = 3–12. Single animals were used for additional time points. A statistically significant decrease in retinoic acid levels was observed in serum of KO females relative to WT females at 60 min after gavage (*, p = 0.033; n = 16 (KO), n = 12 (WT)). However, at 240 min, serum retinoic acid levels were higher in KO mice (*, p = 0.0005; n = 4 (KO), n = 3 (WT)) (B). No significant differences were observed in serum retinoids of males as well as in liver retinol in males or females (C).