Concentration and composition of human serum lipoproteins at birth

By ultracentrifugation of sera from 69 cord bloods very low (VLDL), low (LDL) and high density lipoproteins (HDL) were obtained and analysed for triglycerides (TG) and cholesterol (CHOL). Electrophoresis in agarose gel was performed on serum, VLDL and LDL + HDL. VLDL lipids were present in all newborns. VLDL contained 30 and 5% of serum TG and CHOL. The range of TG in VLDL was wide (0.02-0.62 mmol/l), but there was a constant ratio between TG and CHOL. The electrophoretic mobility of VLDL was slower than in adults. LDL contained 50% of both serum TG and CHOL, and HDL contained 15 and 50% of these serum lipids. A published formula for calculating CHOL in VLDL and LDL from serum CHOL and TG and CHOL in HDL gave values for CHOL in LDL which corresponded well with the determined values. For VLDL, however, the calculated values were too high.