THE CATABOLISM OF APOLIPOPROTEIN-B FROM VERY-LOW-DENSITY LIPOPROTEIN AND TRIGLYCERIDE-RICH LIPOPROTEIN REMNANTS IN FASTED SEPTIC RATS

The catabolism of apolipoprotein B (apo B) from very low density lipop roteins (VLDL) and triglyceride-rich lipoprotein (TRL) remnants in fas ted control (C) and Escherichia coli-treated septic (S) rats was measu red. In Experiment 1, [I-125]VLDL was injected into rats from C and S groups. Blood was collected from 0 to 60 min postdose and apo B was is olated and counted for radioactivity. No significant difference in the half-life (t1/2) or fractional catabolic rate (FCR) of apo B was obse rved in the VLDL fraction. In Experiment 2, [I-125]TRL remnants were i njected into rats from C and S groups. Blood was collected from 0 to 9 0 min postdose and apo B isolated. The t1/2 was 2.5 times longer in th e S compared with the C and the FCR was slower in the S rats. These ex periments suggest that S rats do not clear triglyceride-rich lipoprote ins as easily as normal-sized lipoproteins.