[Electrophoresis studies of the pre-natal status of serum lipoproteins of various species].

The relative proportions of alpha-, beta-, and pre-beta-lipoproteins in the fetal serum of mouse, rat, rabbit, guinea pig, mini-pig, and man were determined by agarose gel electrophoresis and subsequent scan evaluation. No distinct species-independent, fetal-specific common features could be detected. In mouse, rabbit and rat an increase in alpha-lipoproteins and a decrease of the proportion of beta-lipoproteins can be observed during prenatal development. In human cord serum of the 30th week alpha-LP are prevalent; at delivery their proportion is still 50%, like in the serum of adults. Five of the species investigated reveal low, if any, pre-beta-lipoprotein levels in fetal serum, while those in the adult organism amount to 19-33%. The lipoprotein spectrum of the mini-pig at the end of the gestational period is identical with that of the adult animal. In the serum of the fetal and adult guinea pig no alpha-lipoprotein band is detectable. On the other hand, a pre-albumin fraction appeared in the prenatal period, amounting to 25% of total lipoproteins. In total, the findings reported here reflect a largely species-specific development of the fetal lipoprotein patterns.