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 difference s in their distribution patterns. However, more analogies are evident with hamsters than with rats. Plasma lipoproteins of golden Syrian ham ster comprise significant amounts of the VLDL, LDL and HDL classes, an d 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, respectivel y. The LDL class represents about the 12% of total lipoprotein through out the life-span examined by us (1.5-9-month-old animals). The VLDL f raction shows an age-related increase from 15% in younger animals to 2 4% in older ones. We observed also that in the hamsters the distributi on of cholesterol between free and esterified forms, and the distribut ion of phospholipid classes in the different lipoprotein fractions are more similar to those found in man than to those in the Wistar rat. T his suggests that the golden Syrian hamster, particularly when older t han 6 months, is a better model for experimental studies on lipoprotei n metabolism than Wistar rats.