Plasma Lipid Levels in Normal Post-Absorptive Dogs.

Abstract

In this study 10 healthy male dogs kept under standard conditions of exercise, maintained at a weight that varied less than 5% and fed a constant diet were bled 15 hours post-absorptive over a period of a month, at intervals of 1-16 days. Analyses for total lipid were carried out on 5 cc. samples of plasma according to the methods outlined by Bloor, using also his technique for the colorimetric determination of cholesterol by the Liebermann-Burchard reaction. 1

The reliability of the procedures claimed by Bloor was verified, the total lipid method giving a standard deviation of ±1.4% and the cholesterol ±2.6%. Significant changes in lipid levels were taken as average differences of more than twice the standard deviation, or 5.1%. It was found that the method for phospholipid (1929) was reproducible with a standard deviation of ±4.1% on stock alcohol-ether extracts and on purified petroleum ether solutions of phospholipid, but when applied to the plasma extracts from the dogs under study, low values which could not be duplicated were obtained.

The average standard deviation for 4 post-absorptive determinations of cholesterol was ±6%. The values for the individual dogs varied from 68 mg. % to 118 mg. % with a standard deviation of ±28%.

The total fatty acid levels for the individual animal varied by a standard deviation of ±7%, and the means varied from 205 mg. % to 348 mg. %, with a standard deviation of ±13%.

It is evident that the cholesterol and total fatty acid levels in an individual dog are relatively constant over the period of one month of controlled conditions, ant1 that there may be large differences between one (log atid another. The lowest values for cholesterol and total fatty acid ua-e given by young dogs, and the highest values were obtained from an old dog.