Figure 3. Sdc1^–/– mice exhibit delayed plasma clearance of triglycerides and postprandial lipoproteins.

(A) Clearance of human VLDL apoB-100 was measured by ELISA using human apoB-100–specific mAb MB47. Representative data from 3 different experiments is shown and plotted on a semi-log scale. Wild-type mice, t_1/2 = 46 ± 7 minutes (n = 6 mice); Sdc1^–/– mice, t_1/2 = 92 ± 18 min (n = 6 mice). The difference in t_1/2 between the genotypes was significant (P = 0.0009). (B) Retinol ester clearance was measured in wild-type (filled circles, n = 3), and Sdc1^–/– (open circles, n = 3) mice. Animals were fasted for 4 hours and given 200 μl of corn oil containing [³H]retinol by gavage. Blood samples were taken and radioactivity remaining in 10 μl of serum was determined by scintillation counting. The values are expressed as mean ± SD. The areas under the curve were 4,100 ± 1,200 for the wild-type and 8,400 ± 30 for Sdc1^–/– mice. Clearance was significantly delayed in Sdc1^–/– mice compared with wild-type (P = 0.0034). Right: Triglyceride values were measured 4 hours after injection. (C) Sdc1^–/– mice were injected with AdSdc1 (n = 6 mice) or AdGFP (n = 6 mice). Plasma retinol ester levels were measured as described above and compared with wild-type mice (filled circles). The areas under the curve were 3,700 ± 1,100 for wild-type, 7,400 ± 2,600 for AdGFP Sdc1^–/–, and 3,200 ± 900 for AdSdc1 Sdc1^–/–. Animals treated with AdSdc1 demonstrated clearance similar to that wild-type animals (gray circles, P = 0.1272) and significantly faster clearance than Sdc1^–/– mice treated with AdGFP (P = 0.0037).