Tissues from wild-type dams on the vitamin A excess (220 IU of vitamin A/g diet) or sufficient (14 IU of vitamin A/g diet) diet during pregnancy with or without β-carotene (BC) supplementation by intraperiotenal injection (or vehicle, Veh) are from previously published studies from our laboratories [72,84]. (A) Placental qPCR analysis of Mttp, its transcriptional activator Hnf4a, and apoB in WT dams on a vitamin A sufficient or excess diet administered vehicle (Veh) or β-carotene at mid-gestation and sacrificed after 24 h. Data are presented as mean ± S.D. of duplicate determinations and are representative of three independent determinations. n= 1–2 placentas/dam from four to six wild-type dams per group. Statistical analysis by ANOVA. *, p < 0.05. Data for the vitamin A sufficient diet group where previously published (78). (B) Placental MTP activity expressed as percent transfer of lipids/mg/h (n = 1–3 placentas/dam from 3–4 β-carotene-treated dams). Dams as in panel A. (C) Ratio of β-carotene content in each placenta and its corresponding embryo expressed as percent. β-carotene was directly injected into the placentas of wild-type dams at 14.5 dpc, as previously described [84].. Data from dams on the vitamin A sufficient diet pretreated with the MTP inhibitor lomitapide (14 IU MTPi) or not (14 IU) were previously published [84].. β-carotene levels in placenta and embryos were measured by HPLC [80] Individual values are shown. n = 1–7 placentas/dam from 4 wild-type dams per group.