Serum cholesterol levels of inbred rats

¹ Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania

Changes in serum cholesterol levels with age have been studied in male and female rats of three inbred strains (BN, DA, and Lewis) and one random-bred strain (Wistar). The mean serum cholesterol levels at each age differed among strains. Serum cholesterol levels (mg/100 ml) for male rats at 30, 60, and 90 days were: BN-65, 46, and 47; DA-105, 85, and 101; Lewis-79, 76, and 57; and Wistar-64, 63, and 73. For female rats the values were: BN-56, 45, and 47; DA-86, 74, and 91; Lewis-77, 83, and 67; and Wistar-59, 71, and 83. The variation of serum cholesterol with age was different between strains, but similar for males and females within each strain. There was no correlation between body weight and serum cholesterol. Liver cholesterol levels (mg/100 g) determined at 90 days were, for the males, BN-187, DA-233, Lewis-247, and Wistar-300, and for the females, BN-188, DA-244, Lewis-216, and Wistar-249. No correlation with body weight or serum cholesterol was observed.

Key Words: sex differences • strain differences • liver cholesterol

Submitted on December 13, 1963