MICROAFFINITY CHROMATOGRAPHIC-SEPARATION AND CHARACTERIZATION OF LIPOPROTEIN FRACTIONS IN RAT AND MONGOLIAN GERBIL SERUM

A rapid, routine microaffinity chromatographic procedure with spectrom etric detection was evaluated to measure the concentration of total an d free cholesterol, triglycerides, and phospholipids linked to the alp ha- and beta-/pre-beta-lipoproteins in very small serum samples from s mall experimental animals and from humans. This procedure overcomes ma ny of the limitations presented by methods involving ultracentrifugati on, electrophoresis, or precipitation. Using this method, we report th at in 35 adult male Mongolian gerbils (Meriones unguiculatus) fed a ba sal commercial diet with no cholesterol supplementation, the mean (+/- SD) concentration of total and free cholesterol linked to the alpha-l ipoprotein fraction (in mmol/L) is 2.85 +/- 0.81 and 0.33 +/- 0.14, re spectively; phospholipids were 1.99 +/- 0.41, and triglycerides were 0 .64 +/- 0.42. The concentration (mmol/L) of total and free cholesterol associated with the beta-/pre-beta-lipoprotein fraction is 0.92 +/- 0 .26 and 0.22 +/- 0.06, respectively; phospholipids were 0.28 +/- 0.17, and triglycerides were 0.49 +/- 0.31.