WHY PREFER THE GOLDEN SYRIAN-HAMSTER (MESOCRICETUS-AURATUS) TO THE WISTAR RAT IN EXPERIMENTAL STUDIES ON PLASMA-LIPOPROTEIN METABOLISM

Plasma lipoproteins in human and rodent species show marked differences in their distribution patterns. However, more analogies are evident with hamsters than with rats. Plasma lipoproteins of golden Syrian hamster comprise significant amounts of the VLDL, LDL and HDL classes, and the HDL fraction does not appear to be divided into subclasses. HDL is the main Lipoprotein class and shows an age-related reduction from 73% to 65% of total lipoproteins in young and old animals, respectively. The LDL class represents about the 12% of total lipoprotein throughout the life-span examined by us (1.5-9-month-old animals). The VLDL fraction shows an age-related increase from 15% in younger animals to 24% in older ones. We observed also that in the hamsters the distribution of cholesterol between free and esterified forms, and the distribution of phospholipid classes in the different lipoprotein fractions are more similar to those found in man than to those in the Wistar rat. This suggests that the golden Syrian hamster, particularly when older than 6 months, is a better model for experimental studies on lipoprotein metabolism than Wistar rats.