Brain Cell and Tissue Recovery in Rats Made Deficient in n-3 Fatty Acids by Alteration of Dietary Fat

Abstract

Rats were fed a purified diet containing either 1.5% sunflower oil [940 mg linoleic acid [18:2(n-6)]/100 g diet; 6 mg alpha-linolenic acid [18:3(n-3)]/300 g diet] or 1.9% soybean oil [940 mg 18:2(n-6)/100 g diet; 130 mg 18:3(n-3)/100 g diet]. In all cases and tissues examined 22:6(n-3) was lower and 22:5(n-6) was higher in rats fed sunflower oil than in rats fed soybean oil. Levels of 22:4(n-6) and 20:4(n-6) were largely unaffected. Expressed as a percentage of that in soybean oil-fed rats, 22:6(n-3) in sunflower oil-fed rats was as follows: neurons, 49; astrocytes, 47; oligodendrocytes, 10; lung, 27; testes, 32; retina, 36; liver, 35 and kidneys, 45. Ten wk after the change in diet of 60-d-old rats from one containing sunflower oil to one containing soybean oil, the fatty acid composition of the brain cells had not reached control values, e.g., that obtained in animals continuously fed soybean oil; 22:6(n-3) was 77, 65 and 80% of control levels for astrocytes, oligodendrocytes and neurons, respectively. In contrast, the recovery measured by the decay of 22:5(n-6) was complete within 10 wk. For 22:6(n-3), it took approximately 2 wk for liver and kidney to recover to the control value, 3 wk for lung, 6 wk for retina and 10 wk for testes. The decrease of 22:5(n-6) was rapid: the control values were reached within 2 wk for kidney, liver and lung and within 6 wk for retina.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary low linolenic acid compared with docosahexaenoic acid alter synaptic plasma membrane phospholipid fatty acid composition and sodium–potassium ATPase kinetics in developing rats

“…The low V max of Na,K-ATPase in SPM of rats fed low LNA compared with rats fed control or AA + DHA diet is similar to that reported by Bourre et al (1989) and Tsutsumi et al (1995). The increased 22:5n-6 and decreased 22:6n-3 in the low LNA compared with control or AA + DHA fed rats may account for the low V max in low LNA compared with control or AA + DHA fed rats at two and five weeks of age.…”

“…Alterations in diet fat have been shown to induce changes in the phospholipid content (Foot et al 1982;Hargreaves and Clandinin 1987) and fatty acyl composition of SPM (Foot et al 1982), accompanied by alterations in activity of membrane-associated enzymes (Foot et al 1983;Tsutsumi et al 1995;Gerbi and Maixent 1999), and regulation of neurotransmitters (Zimmer et al 1998;Innis and de la Presa Owens 2001). Feeding rats and their offspring diets deficient in 18:3n-3 linolenic acid (LNA) dramatically alters the fatty acid composition of SPM phospholipids by decreasing n-3 PUFA and increasing n-6 PUFA, particularly, 22:4n-6 and 22:5n-6 (Bourre et al 1989). Long-term n-3 deficiency affects membrane-bound enzyme activities (Bourre et al 1984) decreasing Na,K-ATPase activity at optimal (Bourre et al 1984) and sub-optimal (Tsutsumi et al 1995) ATP concentrations.…”

Can Prenatal N-3 Fatty Acid Deficiency Be Completely Reversed after Birth? Effects on Retinal and Brain Biochemistry and Visual Function in Rhesus Monkeys

“…Bourre et al (36) found that brain levels of DHA were slow to reach normal levels when prenatally n-3 fatty acid deficient rats were switched to a repletion diet at 60 d of age. Ten weeks later, brain DHA had increased to only approximately 75% of control, although brain 22:5(n-6) decayed completely to control values within this time period.…”

Essential fatty acids as determinants of lipid requirements in infants, children and adults

“…Essential fatty acids R Uauy et al S67 from humans have established that brain phospholipid DHA decreases while n-9 and n-7 mono-and polyunsaturated fatty acids increase when LA and LNA or only n-3 fatty acids are de®cient in the diet (Galli et al, 1971;Menon & Dhopeshwarkar, 1982;Bourre et al, 1989a). Typically, n-3 fatty acid de®cient cells have decreased DHA and increased levels of the end products of n-6 metabolism, docosapentaenoic acid (DPA).…”