Apolipoprotein C-II synthesis as studied in explants of rat liver in culture.
Adult male Sprague-Dawley rats (200-250 g) were used to study apolipoprotein C-II synthesis and secretion. Liver slices were prepared and incubated in RPMI 1629-medium (tissue amount and incubation time studies) and in Minimum Essential Medium (Eagle) with Earle's salts (hormone experiments). Incubation was performed in scintillation vials in a 95% O2-5% CO2 atmosphere, at 37 degrees C from 1 to 21 hr (2 and 4 hr with hormones). The hormones used and their amounts per millilitre medium were: oestradiol-17 beta 0.1 microgram, progesterone 3.0 micrograms and dexamethasone 1.5 micrograms. Apolipoprotein C-II was determined by specific double immunoprecipitation technique and TCA-insoluble protein fraction represented total protein. Optimal tissue amount was 100 mg/vial and the results show that liver slices quickly secrete the newly synthesized apo C-II (also total protein) into the surrounding medium. There were only minor differences between apo C-II values with the hormones used. The portion of apo C-II synthesis from total protein synthesis was 0.47-1.50%. After 4 hr incubation the [3H]leucine incorporation was almost equal for controls and hormone treated slices.
D000818:Animals; D053304:Apolipoprotein C-II; D001053:Apolipoproteins / Q000096:biosynthesis*; D001056:Apolipoproteins C; D011232:Chemical Precipitation; D046508:Culture Techniques; D003600:Cytosol / Q000378:metabolism; D007120:Immunochemistry; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D053304:Apolipoprotein C-II; D001053:Apolipoproteins; D001056:Apolipoproteins C