Figure 6. Hepatic total and VLDL and HDL apoB synthesis and secretion in mice expressing hMTP and dMTP.

(A–B) Synthesis and secretion of apoB-lipoproteins by the livers of dMTP and hMTP mice: 72 h after virus injection, mice were fasted (4 h) and intravenously injected with [³⁵S]-Promix (1 mCi). After 30 min, P407 was injected intraperitoneally and blood was collected at indicated times. Plasma (15 µl) was fractionated by 5% SDS-PAGE, dried and fluorogrpahed (A). ApoB48 and apoB100 bands were dissolved in Soluene (Perkin Elmer) and counted. Counts at 5 min, were subtracted before plotting (B). (C–F) Mice were labeled and plasma samples were collected as described above. Plasma lipoproteins were separated by FPLC. VLDL were pooled, immunoprecipitated using rabbit anti-mouse apoB antibodies, separated by SDS-PAGE and fluorographed (C) and counts in apoB48 and apoB100 bands were quantified (D), Mean ± SEM, n=4. ApoAI-lipoproteins were removed from HDL by immunoprecipitation, and apoAI-free supernatants were precipitated with anti-apoB antibodies, separated on gels and fluorographed (E). Counts in HDL-apoB48 bands were plotted (F). ^***p < 0. 001, ^**p < 0. 01, ^*p < 0. 05.