Intersex differences in plasma lipid content and in various lipoprotein fractions in New Zealand albino rabbits.

Total lipids in plasma were determined and also the content of cholesterol, triglycerides, phospholipids and proteins were assayed in various lipoprotein fractions (VLDL, LDL, HDL) isolated by means of preparative ultracentrifugation, in rabbits of both sexes of the New Zealand albino strain. Significant intersex differences were noted in total plasma lipids as also in the cholesterol, triglyceride and phospholipid content in all the lipoprotein fractions. These parameters proved to be significantly higher in females than in males. Cholesterol content was higher in the fraction of low density lipoproteins (LDL) and lower in that of high density lipoproteins (HDL) in the males. As to females, cholesterol was uniformly distributed in both the LDL and HDL fractions. Determination of the representation of the various apoproteins with the aid of gel electrophoresis failed to yield any intersex differences.