linoleic-acid and Kidney-Diseases

Topics: Animals; Autoimmune Diseases; Dietary Fats; Fatty Acids, Essential; Fish Oils; Humans; Kidney Diseases; Linoleic Acid; Linoleic Acids

Analysis of oxylipins derived from fatty acids may provide insight into the biological effects of dietary lipids beyond their effects on tissue fatty acid profiles. We have previously observed that diets with higher amounts of α-linolenic acid (ALA; 18:3n3) are associated with reduced obesity-related glomerulopathy (ORG). Therefore, to examine the renal oxylipin profile, the effects of dietary linoleic acid (LA; 18:2n6) and ALA on oxylipins and renal phospholipid fatty acid composition, and the relationship between oxylipins and ORG, diet-induced obese rats displaying ORG were fed 8 different diets for 8 wk as follows (oil/oil = combination of two oils) [shown as ALA/LA (in g) per 100 g oil]: canola/flax (20/18), canola (8/18), soy (9/53), high-oleic canola/canola (5/16), high-oleic canola (2/15), lard/soy (1/8), and safflower (0.2/73). Targeted lipidomic analysis by HPLC-tandem mass spectrometry revealed that LA and ALA oxylipins comprised 60% of the total renal oxylipin profile examined. Of the >60 oxylipins screened, only those derived either directly or indirectly from ALA were associated with less glomerulomegaly, indicative of reduced ORG progression. Both the amount and ratio of dietary LA and ALA influenced renal polyunsaturated fatty acids (PUFAs); in contrast, only fatty acid amount altered oxylipins derived from these fatty acids, but there was no apparent competition by LA or ALA on their formation. Dietary LA incorporation into renal phospholipids was higher than for ALA, but ALA oxylipin:ALA ratios were higher than the analogous LA ratios for select lipoxygenase reactions. This indicates that the effect of dietary ALA on renal oxylipins exceeded what was reflected in renal PUFA composition. In conclusion, dietary LA and ALA have differential effects on renal oxylipins and PUFAs, and ALA-derived oxylipins are associated with renoprotection in this model of ORG.

Topics: alpha-Linolenic Acid; Animals; Diet; Dietary Fats; Dietary Fats, Unsaturated; Fatty Acids, Monounsaturated; Kidney; Kidney Diseases; Linoleic Acid; Male; Obesity; Oxylipins; Phospholipids; Rapeseed Oil; Rats; Rats, Sprague-Dawley; Safflower Oil; Soybean Oil

Hypertension is a major risk factor for cardiovascular diseases and is detrimental to several organs including the liver and kidneys. The flaxseed-derived polyunsaturated fatty acids including the omega-3 and omega-6 essential fatty acids have been shown to blunt the effects of hypertension. It is however, unclear whether the flaxseed, which is rich in these essential fatty acids, could improve the liver and kidney dysfunctions observed in the hypertensive condition. To test this, functional markers of the liver and kidneys, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), uric acid (UA), creatinine, and renin were examined in hypertensive male Wistar rats fed a flaxseed diet. Normotensive rats maintained on a standard diet were rendered hypertensive with a daily administration of cyclosporin A (CYS) (25 mg/kg) for 4 weeks. Subsequently, hypertensive rats were either fed a standard diet alone or a flaxseed-supplemented standard diet (FLX; 10% W/W) for 8 weeks. Compared to normotensive rats, standard diet-fed hypertensive rats had significantly elevated blood pressure, altered lipid profile, and increased plasma levels of tissue markers measured immediately following the CYS treatment and thereafter at 4 and 8 week intervals. On the other hand, rats fed the FLX-supplemented diet had significantly lower blood pressure, an improved lipid profile and decreased tissue marker levels measured after 4 and 8 week durations. The data demonstrate for the first time the favourable effects of FLX in improving liver and kidney functions in the hypertensive condition. These effects are likely to be mediated by the alpha-linolenic acid (ALA) and linoleic acid (LA) contents of flaxseed oil due to its demonstrated ability to lower the blood pressure.

Topics: alpha-Linolenic Acid; Animals; Blood Pressure; Dietary Supplements; Hypertension; Kidney Diseases; Kidney Function Tests; Linoleic Acid; Linseed Oil; Liver Diseases; Liver Function Tests; Male; Rats; Rats, Wistar

Dietary supplementation with polyunsaturated fatty acids (PUFAs) has been shown to alter the course of experimental renal disease. Although hemodynamic factors such as glomerular hypertension are felt to be important in the progression of renal disease, the effects of dietary PUFA supplementation on glomerular hemodynamics are unknown. The present investigation, therefore, was designed to evaluate the glomerular hemodynamic effects of dietary PUFA supplementation in normal rats. Male Sprague-Dawley rats were fed standard chow supplemented with either 20% (wt/wt) fish oil (FO) as a source of omega-3 PUFAs, 20% sunflower oil (SO) as a source of omega-6 PUFAs, or 20% coconut oil (CO) as a control diet. Micropuncture studies were performed after 4 to 6 weeks of dietary supplementation. Compared with CO rats, SO rats did not demonstrate any changes in glomerular hemodynamics. However, rats supplemented with FO demonstrated significant (p less than 0.05) increases in both single nephron glomerular filtration rate and single nephron plasma flow. These hemodynamic changes were not associated with alterations in glomerular capillary hydraulic pressure or the glomerular ultrafiltration coefficient. The increase in SNPF was primarily the consequence of a 37% reduction (p less than 0.05) in efferent arteriolar resistance. Thus dietary FO supplementation resulted in glomerular hyperfiltration and hyperperfusion. These hemodynamic actions may have important consequences in determining the effect of omega-3 PUFAs on the course of experimental and clinical renal disease.

Topics: Animals; Blood Pressure; Dietary Fats, Unsaturated; Food, Fortified; Hemodynamics; Kidney Diseases; Kidney Glomerulus; Linoleic Acid; Linoleic Acids; Male; Rats; Rats, Inbred Strains

1. Functional renal failure (FRF) in cirrhosis with ascites could be related to an inappropriately low renal prostaglandin (PG) production. To investigate whether the impaired renal PG synthesis in these patients is related to a PG precursor fatty acid deficiency, serum levels of linoleic and arachidonic acids and the urinary excretion of PGE2, 6-keto-PGF1 alpha and thromboxane B2 (TxB2) were measured in 10 normal subjects, 17 non-azotaemic cirrhotic patients with ascites and 10 cirrhotic patients with ascites and FRF. 2. Serum linoleic acid levels were similar in the three groups studied. Both groups of cirrhotic patients showed lower arachidonic acid levels than normal subjects; however, non-azotaemic cirrhotic patients and patients with FRF did not differ in relation to serum arachidonic acid. 3. Non-azotaemic cirrhotic patients had higher urinary PGE2, 6-keto-PGF1 alpha and TxB2 excretion than normal subjects and cirrhotic patients with FRF. Patients with FRF showed similar urinary PGE2 and TxB2 and lower urinary 6-keto-PGF1 alpha than normal subjects. In all cirrhotic patients no significant correlation was found between serum linoleic and arachidonic acid levels and urinary PGs. 4. In seven patients with FRF an acute intravenous infusion of linoleic acid induced a marked increase in serum levels of this fatty acid. However, no increase in serum arachidonic acid levels and urinary PG excretion and no improvement in renal function was observed. 5. This study suggests that an arachidonic acid deficiency is present in cirrhotic patients with ascites but that this abnormality is not a major determinant of renal function and PG production in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Arachidonic Acid; Arachidonic Acids; Female; Humans; Kidney; Kidney Diseases; Linoleic Acid; Linoleic Acids; Liver Cirrhosis; Male; Middle Aged; Prostaglandins