DECREASED SECRETION OF VERY-LOW-DENSITY LIPOPROTEIN TRIACYLGLYCEROL AND APOLIPOPROTEIN-B IS ASSOCIATED WITH DECREASED INTRACELLULAR TRIACYLGLYCEROL LIPOLYSIS IN HEPATOCYTES DERIVED FROM RATS FED OROTIC-ACID ORN-3 FATTY-ACIDS

Hepatocytes from rats fed a chow (control) diet or from rats fed a cho w diet supplemented with either erotic acid (OA; 1 %, w/w) or fish oil (FO; 20%, v/w) were maintained in culture for periods up to 48 h. Dur ing the first 24 h period, the low rates of output of very-low-density lipoprotein (VLDL)-associated triacylglycerol (TAG) and apolipoprotei n B (apoB) in hepatocytes from the FO- and OA-fed animals were associa ted with significantly lower rates of intracellular TAG lipolysis and reesterification. Most of the VLDL TAG secreted was mobilized via lipo lysis of the intracellular TAG pool, but the proportion of VLDL TAG se creted via this route in cells from the FO-fed and OA-fed animals was decreased compared with that in the controlled animals' cells. In the presence of exogenous oleate the inhibitory effect of OA feeding on VL DL apoB and TAG secretion persisted in the derived hepatocytes for up to 48 h following isolation. However, when oleate was absent no inhibi tory effect on the secretion of TAG and apoB was observed between 24 a nd 48 h. Under these conditions the rate of intracellular TAG turnover returned to normal. The initial inhibitory effect of FO feeding on VL DL TAG and apoB secretion did not persist in the derived hepatocytes b etween 24 h and 48 h of culture in the presence of exogenous oleate. A lthough intracellular TAG lipolysis and VLDL TAG and apoB secretion ra tes appear to be positively correlated, a causal relationship has not been conclusively established.