Modification to dietary intake of sodium, potassium, calcium, magnesium and trace elements can influence arachidonic acid metabolism and eicosanoid production

Level of Potassium Is Associated with Saturated Fatty Acids in Cell Membranes and Influences the Activation of the 9 and 13 HODE and 5 HETE Synthesis Pathways in PCOS

Potassium helps to maintain the water–electrolyte and acid–base balance. There is little research on the relationship between plasma fatty acids (FAs), inflammatory mediators and red blood cell potassium levels in women with polycystic ovary syndrome (PCOS). This study included 38 Caucasian women with PCOS. Potassium in the erythrocytes was determined by inductively coupled atomic plasma emission spectrometry. The FAs were analysed with gas chromatography, and liquid chromatography was used to separate the eicosanoids. The relationships between the potassium content and the amounts of fatty acids, as well as potassium and arachidonic acid (AAs) derivatives, were analysed. Significant negative correlations were found with, among others, pentadecanoic acid, palmitic acid, stearic acid and arachidic acid, whereas a positive correlation was found with neuronic acid. Positive correlations were observed with 9, 13 HODE (derivatives synthetized from linolenic acid) and 5 oxo ETE and 5 HETE (from 5 LOX pathway). Saturated fatty acids reduce the influx of potassium into the cell by destabilizing the pH of the cytosol, and thus exacerbating the inflammatory response through the activation of the AA cascade. Therefore, improving the flow of potassium inside the cell is important in the treatment of patients.

Potential role of dietary lipids in the prophylaxis of some clinical conditions

An imbalance of dietary lipids may potentially have a significant role in the pathobiology of some chronic diseases. Public health dietary fat recommendations have emphasized that low saturated fat, high monounsaturated fat, and high polyunsaturated fat with a lower ω-6 to ω-3 fatty acid ratio intake are necessary for normal health. However, such universal recommendations are likely to be hazardous, since the outcome of recommended lipid intake may depend on the consumption of other important dietary constituents that have an important role in the metabolism of lipids. In addition, consumption of fatty acids as per the individually tailored specific requirements in the context of other nutritional factors may have the potential to stabilize hormones, mood and sleep, and minimize adverse events. In support of this proposal, we review various factors that influence fatty acid metabolism, which need to be taken into consideration for appropriate utilization and consequently prevention of various diseases.

Interrelationship of ascorbate, arachidonic acid and prostaglandin E2 in B16 melanoma cells

Previous studies have shown that ascorbate (Asc) supplementation affects arachidonic acid (AA) and prostaglandin E2 (PGE2) levels in B16 murine melanoma cells. In this study, non-malignant LLCMK cells and malignant B16 cells were respectively supplemented with 20 microCi 15-3H AA, to investigate whether these two cell types were able to take up AA from the media. Furthermore, these cells were also supplemented with Asc (0-100 micrograms/ml) to determine the effect of Asc supplementation on 15-3H AA uptake. Both cell types incorporated 15-3H AA, while Asc supplementation enhanced this 15-3H AA uptake. To determine the site of the AA incorporation, both cell types were supplemented with 2.5 microM AA and Asc (0-100 micrograms/ml). The % AA composition of the stroma fractions of both cell types was increased with 100 micrograms/ml Asc supplementation. Supplementation of these cells with AA (0-50 microM) resulted in an increase in PGE2 levels in the B16 cells. Since PGE2 has been shown, in turn, to stimulate adenylate cyclase (AC) activity, the LLCMK and B16 cells were supplemented with 0-100 microM PGE2. A 3-fold increase of AC activity in the B16 cells occurred as a result of this supplementation.

Effects of starvation on the urinary contents of primary thromboxane and prostacyclin metabolites and a possible selenium-dependent role of prostacyclin in the renal handling of ketone bodies

The aim of this study was to investigate whether urinary prostanoids, as an index of renal synthesis of these compounds, are affected in selenium (Se) deficiency and, if so, whether such changes could add to our understanding of the high excretion of ketone bodies in Se-deficient rats (p < 0.005 vs Se-adequate rats). Male rats were fed a Se-deficient diet with less than 0.01 mg Se/kg or the same diet supplemented with 0.2 mg Se/kg. The urinary contents of prostaglandin E2 (PGE2), PGF2 alpha and 6-keto PGF1 alpha were not significantly affected by the Se status. However, there was a positive correlation between the urinary contents of ketone bodies and 6-keto PGF1 alpha in Se deficiency (with p < 0.02 for acetaoacetate and p < 0.05 for 3-hydroxybutyrate). In contrast, only negative (nonsignificant) relationships were observed between these same parameters in Se-adequate rats. No correlations between urinary contents of ketone bodies and PGE2, PGF2 alpha or thromboxane B2 (TXB2) were obtained. Compared to fed rats, starvation caused a 4-fold increase in the urinary TXB2 content in Se-adequate, as well as in Se-deficient rats (p < 0.001). Starvation had an opposite effect on the content of 6-keto PGF1 alpha, which decreased (to 64% that of fed animals p < 0.001) in Se-adequate rats and, nonsignificantly (to 93% that of fed animals) in the Se-deficient group. It is concluded that starvation profoundly affects the urinary contents (and thus, probably renal synthesis) of TX and prostacycline (PGI2).(ABSTRACT TRUNCATED AT 250 WORDS)