Christer Alling

Lipid alterations in apparently normal white matter in multiple sclerosis

Abstract Apparently normal white matter from 6 subjects who had multiple sclerosis (MS) for 5–41 years was compared with roughly age-matched normal material. Determinations were made of the concentrations and fatty acid patterns of all major lipid classes except gangliosides. Cholesterol, phospholipids and galactolipids were slightly lower in the MS brains, but significantly lower values were found only for serine phophoglycerides and sulfatides. The fatty acid patterns of the MS brain were strikingly similar to those of the normal brains. Nevertheless the concentrations of some of the fatty acids characteristic of white matter were slightly lower in the MS brains. The investigation produced no evidence for a primary lipid defect of myelin. The abnormalities in the lipid and the fatty acid composition might instead be completely explained by the presence of small lesions overlooked at isolation of apparently normal white matter.

The Effect of Different Dietary Levels of Essential Fatty Acids on Growth of the Rat

Sprague-Dawley rats received three dietary levels of essential fatty acids (EFA) during gestation and the suckling period and up to adult age by raising them on their respective diets for more than two generations. The relative difference in body weight was most pronounced between 13 and 23 days of age, after which it gradually diminished. Between 25 and 60 days of age, rats fed 0.07 cal% EFA had a significantly lower body weight than rats fed 0.75 cal% and the latter had a significantly lower body weight than those fed 3.0 cal%. The difference was slightly more Pronounced for females than for males.

Effect of Different Dietary Levels of Essential Fatty Acids on Liver and Serum Lipids in the Rat

Rats were fed diets with three different levels of essential fatty acids (EFA); 3.0, 0.75 and 0.07 cal·% for more than two generations. The concentrations of serum phospholipids and cholesterol rose during the suckling period and fell rapidly after weaning. In the liver the triglycerides reached their highest value early in the suckling period. The concentration of the triglycerides was the same in the EFA-deficient groups as in the control group. The fatty acid patterns of serum and liver lecithins in the four dietary groups were similar in several respects, but the concentration of the highly unsaturated fatty acids, primarily arachidonic and docosahexaenoic acids, were higher in the liver. The largest deficiency of EFA in serum and in liver was found at birth and during the late suckling and early postsuckling periods. This deficiency was compensated for mainly by an increase in the fatty acid 20:3 (n-9) as well as in the monoenoic acids 16:1 and 18:1. The proportions of fatty acids of the linolenic acid series were reduced more than those of the linoleic acid series at all ages, both in the groups which received 0.75 and in those which received 0.07 cal% EFA.

CHROMATOGRAPHIC STUDIES OF THE LIPIDS IN CEREBROSPINAL FLUID (CSF)

During the last fifty years several attempts have been made to obtain a quantitative estimation of the lipids in CSF. Tourtellotte (1958 a) and Munk Plum (1964) have given complete reviews of the literature in this field. Determinations of cholesterol and total phospholipids have received the most attention. As the amount of lipids present in a limited sample of CSF is very small, about 1-2mg per cent, the determination may give rise to considerable experimental errors. To rectify technological objections Tourtellotte (195Sb, 1958c, 1959a and 1959b) has proposed an analytical scheme, suitable for small samples of CSF. Though this method was an advance, the inaccuracy is marked, yielding results of limited value as will be illustrated later in this paper. I n recent years improved c;hromatographic technics have greatly increased the ability to separate, identify and now even to estimate quantitatively the different lipids in CSF. The first attempts were made partly by Curtis & Xeipel (1961) with the use of silicic acid-impregnated glass paper, and partly by Blomstrand & Nakayama (1961) with ordinary paper chromatography and subsequent analysis by neutron activation. The technic of thin layer chromatography, which was mainly worked out by Xtahl (1956), has since that time been applied to the determination of phospholipids and glycolipids in nervous tissue. The quantitative application of this method for cerebral lipids has recently been reported by Davison & GrahamWolfaard (1964) and Jatzekewitz (1964). In this method the spots, together with the silica gel layer, are scraped off for subsequent microanalysis. A densitometric estimation, after thin layer chromatography, of cerebral lipids has recently been reported by Payne (1964). Two essential papers concerning the lipids in CSF, have been published, dealing with the two possible chromatographic procedures. One is by McArdle & Zilkha (1962) using paper chromatography, the other is by Phillips & Robinson (1963) using thin layer chromatography. With these two different methods, very similar results have been achieved concerning the normal amount of the different lipids and indicate that the phospholipid pattern is very similar in CSF and serum. On the other hand, it is known that nervous

The Effect of Different Dietary Levels of Essential Fatty Acids on Body Composition of the Rat

Three dietary levels of essential fatty acids (EFA) 3.0, 0.75, and 0.07 cal% were studied for their influence on the concentration of lipids, linoleic and arachidonic acids, water, nitrogen, potassium

Effect of different dietary levels of essential fatty acids on the fatty acid composition of lecithin in rat skeletal muscle.

Three dietary levels of essential fatty acids (EFA); 3.0, 0.75 and 0.07 cal%, and with a linoleic/linolenic acid ratio of 4:1, were fed to rats for more than two generations. The phospholipid concentration and fatty acid composition of lecithin in skeletal muscle were analyzed from term to 120 days of age. Muscle from rats, fed the 3.0- and 0.75-cal% diets, always had a higher concentration of phospholipids than those of rats fed the 0.07-cal% diet. At all ages the concentration of polyenoic acids in the muscle lecithin was influenced by the level of EFA in the diet, but after the age of 45 days, the difference between rats fed 3.0 and 0.75 cal% EFA was very small. The most pronounced influences were found at birth and at weaning of the rats. The sums of fatty acids of the linoleic and linolenic acid series were diminished roughly to the same extent, when rats fed 0.75 cal% were compared to those fed 3.0 cal%, but the levels of fatty acids of the linolenic acid series were more reduced than those of the linoleic acid series in the rats fed 0.07 cal% EFA. Arachidonic acid varied more with the dietary level of EFA than did linoleic acid, while the minor fatty acids of the linoleic acid series were only slightly affected. The deficiency in EFA was to some extent compensated for by the fatty acid 20:3 (n-9), but mainly by monoenoic acids. The saturated fatty acids were not influenced at all.