INCORPORATION OF N-3 POLYUNSATURATED FATTY ACIDS OF MARINE OR VEGETABLE ORIGIN INTO RAT ENTEROCYTE PHOSPHOLIPIDS

Dietary lipids modify brush border membrane composition and nutrient transport in chicken small intestine

The influence of dietary fatty acids (FA) on intestinal brush border FA composition and nutrient transport functions was studied in broiler chickens. Ross chicks (2 wk old) were fed for 14 d a standard diet (CTL) or diets enriched with saturated fatty acids (SFA; 60 g/kg lard, LAR diet), (n-3) PUFA (60 g/kg linseed oil, LSO diet) and (n-6) PUFA (60 g/kg sunflower oil, SFO diet). The SFA of the brush border membrane were within 40-44% of total FA in spite of wide variability in dietary SFA concentration (13-32%); membrane (n-6) and (n-3) PUFA strongly reflected their dietary intake and thus the (n-6)/(n-3) ratio. However, the membrane polyunsaturated/saturated ratio (P/S) was close to unity, whereas in the diets, it was between 0.9 and 5. The transport kinetic constants (V(max), K(m), K(d)) of D-glucose (substrate of the sodium glucose cotransporter 1), L-lysine (through systems b(0,+) and y(+)(m)) and L-methionine (through systems B and L) were studied in jejunal brush border membrane vesicles. The changes in dietary FA intake did not affect the K(m) of the substrates for their transporters. Both LAR and SFO diets reduced the D-glucose V(max), which was compensated for by an increase in the K(d). The LAR diet reduced lysine transport across y(+)(m), whereas the LSO diet increased the V(max) for both lysine and methionine.

Plasma phospholipid fatty acid pattern in severe liver disease

BACKGROUND/AIMS

In acute liver failure the liver has to regenerate, which may increase the consumption of essential fatty acids. Nutritional support consists mainly of infusion of glucose. It is therefore possible that essential fatty acid deficiency may develop in such patients.

METHODS

Plasma phospholipid composition was studied in healthy controls (n=11), in patients with acute liver failure, (n=10), in patients with stable cirrhosis (n=7), and in patients with acute on chronic liver disease with hepatic encephalopathy (n=6). The influence of 2 days of fat-free diet followed by infusion of glucose was studied in five healthy controls.

RESULTS

The ratio between the sums of nonessential/ essential fatty acids, (n-7+n-9)/(n-3+n-6), was higher in patients with acute liver failure (0.73+/-0.17) compared to healthy controls (0.35+/-0.06, p<0.001). The ratio was also higher in patients with acute on chronic liver disease (1.11+/-0.39) compared to patients with cirrhosis (0.61+/-0.18, p<0.01). These differences were mainly due to low levels of linoleic acid and high levels of oleic acid in the patients with acute liver failure and acute on chronic liver disease. Two days of fat-free diet followed by infusion of glucose did not change this ratio (0.40+/-0.04 vs. 0.47+/-0.05, NS) in healthy controls. The essential fatty acid deficiency indicator eicosatrienoic acid was detectable in 2 out of 11 controls, in 5/10 with acute liver failure, in 7/7 with cirrhosis, and in 6/7 with acute on chronic liver disease.

CONCLUSION

Acute severe deterioration of liver function was associated with changes in the fatty acid composition of plasma phospholipids suggestive of essential fatty acid deficiency.