promega and Body-Weight

The effects of a fish oil supplement on lipid and lipoprotein levels, platelet function, and vital signs were investigated in 31 hypercholesterolemic patients. Thirteen patients took 5 g of encapsulated fish oil per day and 18 patients took 5 g of encapsulated safflower oil "placebo" per day for 28 days. Diet and exercise patterns were kept as constant as possible during the study. The fish oil group had significant increases in several lipid/lipoprotein values at the end of the treatment, including an increase of total cholesterol of 14% (P = 0.0001), LDL of 16% (P = 0.003), HDL of 13% (P = 0.015) and HDL2 of 36% (P = 0.009). The triglyceride level fell 24%, a nonsignificant change (P = 0.217). The ratios of total cholesterol/HDL and LDL/HDL were increased at the end of fish oil treatment, and returned to baseline 30 days after fish oil was stopped. The placebo group had no significant changes in any of the lipid/lipoprotein values. Neither the fish oil nor the placebo group had significant changes in vital signs or platelet function tests (bleeding time, thromboxane B2, platelet factor 4 and beta-thromboglobulin) during the study. These results suggest that fish oil supplements may have an adverse effect on lipid/lipoprotein values in hypercholesterolemic patients.

Topics: Adolescent; Adult; Blood Pressure; Body Weight; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Double-Blind Method; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Female; Fish Oils; Humans; Hypercholesterolemia; Lipids; Lipoproteins; Male; Middle Aged; Platelet Function Tests; Random Allocation

In the present study the putative chemopreventive effect of dietary fish oil (MaxEPA) on azaserine-induced pancreatic carcinogenesis in rats was investigated. Groups of rats were maintained on a semipurified low-fat (LF; 5 wt%) diet or on semipurified high-fat (HF; 25 wt%) diets containing 5 wt% linoleic acid (LA) and including 0.0, 1.2, 2.4, 4.7, 7.1 or 9.4 wt% MaxEPA. Animals fed a HF diet developed significantly higher mean numbers of atypical acinar cell nodules (AACNs), adenomas and carcinomas than animals fed a LF diet. Dietary MaxEPA caused a significant (P < 0.01) dose-related increase in mean number of AACNs (0.5 < phi < 3.0 mm). The mean number of adenomas and carcinomas remained similar among the groups. Cell proliferation was significantly lower in AACNs from animals fed HF containing 9.4% MaxEPA in comparison with HF without MaxEPA and with LF. LA levels had increased and arachidonic acid (AA) levels had decreased in blood plasma and pancreas with increasing dietary MaxEPA. Feeding MaxEPA resulted in significant decreases in 6-keto-prostaglandin (PG) F1 alpha (P < 0.05) and PGF2 alpha (P < 0.01) in non-tumorous pancreas, whereas PGE2, PGF2 alpha and thromboxane B2 (TXB2) levels were significantly (P < 0.001) higher in pancreatic tumour tissue than in non-tumorous pancreatic tissue. It is concluded that (i) dietary MaxEPA enhances dose-relatively growth of putative preneoplastic AACNs in the pancreas of azaserine-treated rats; (ii) dietary MaxEPA inhibits the conversion of LA to AA, as well as the conversion of AA to TXB2 or PGF2 alpha in non-tumorous pancreatic tissue; (iii) the high levels of PGE2, PGF2 alpha and TXB2 in pancreatic adenocarcinomas indicate a possible role for these eicosanoids in modulation of tumour growth.

Topics: Animals; Anticarcinogenic Agents; Azaserine; Body Weight; Carcinogens; Cell Division; Cocarcinogenesis; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Drug Combinations; Drug Synergism; Eating; Eicosapentaenoic Acid; Fatty Acids; Fatty Acids, Omega-3; Female; Fish Oils; Liver; Organ Size; Pancreatic Neoplasms; Precancerous Conditions; Pregnancy; Prostaglandins; Rats; Rats, Wistar

We investigated the effects of dietary MaxEPA (a major source of eicosapentaenoic acid in fish oil) supplementation on blood pressure (BP) responses and heart rate (HR) of Dahl salt-sensitive (SS) rats fed low (0.4% NaCl) and high (8.0% NaCl) sodium diets. During a four week treatment period, BP remained normotensive in rats on low salt diet but was significantly elevated in those on high salt diet, causing 50% mortality. MaxEPA diminished the BP elevation and prevented the high salt-induced mortality. HR was not affected by either salt diet alone but was reduced in the presence of MaxEPA. At the end of the treatment period, the distribution of [3H]nitrobenzylthioinosine ([3H]NBMPR) binding, a putative marker of adenosine transport and metabolism, was estimated in selected rat tissues in order to evaluate the role of the purinergic system in the BP lowering effect of MaxEPA. Maximal [3H]NBMPR binding capacity (Bmax) in the kidney and platelets were 39% and 82% lower, respectively, in rats on high salt diet than in those on low salt diet. MaxEPA significantly blunted the decrease in Bmax in the kidney but not in platelets and increased Bmax in heart (48%) of low salt group. There were no changes in dissociation constants (Kd). The results suggest that MaxEPA can attenuate salt-induced hypertension, reduce salt-induced mortality and protect the integrity of kidney NBMPR binding sites in salt-induced hypertension.

Topics: Affinity Labels; Animals; Binding Sites; Blood Platelets; Blood Pressure; Body Weight; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Heart Rate; Hypertension; Kidney; Male; Rats; Rats, Sprague-Dawley; Sodium Chloride, Dietary; Thioinosine

The Mrl lpr/lpr (Mrl/l) mouse is a model for systemic lupus erythematosus and rheumatoid arthritis in humans. The diet of Mrl/l mice was supplemented with EPA (see Introduction) in menhaden oil or in the commerical fish oil MaxEPA. The survival of mice was not affected by the dietary manipulations. The addition of menhaden oil decreased the severity of the renal pathology. However, MaxEPA containing the same amount of eicosapentaenoic acid was considerably less effective. A diet deficient in polyunsaturated fatty acids did not ameliorate any manifestations of the disease. Anti-DNA antibody levels in serum were not influenced by the therapy. Myocardial abscesses and/or ulcerating valvular lesions were observed in about one third of the mice, irrespective of the diet given.

Topics: Animals; Body Weight; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Female; Fish Oils; Kidney; Lupus Erythematosus, Systemic; Lymph Nodes; Mice; Myocardium; Skin Ulcer

This study was designed to investigate the effects of dietary modification of prostaglandin (PG) synthesis on blood pressure regulation in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats under conditions of normal and elevated salt intake. Forty rats from both strains were placed on either a two-series PG inhibitory diet of Max eicosapentaenoic acid (EPA) fish oil or a control diet of saturated fat for an initial period of 4 weeks. The groups were then divided into two, so that half of each received 1.5% saline in place of their drinking water for 1 week. Blood pressure of the SHR and WKY were unaffected by dietary fat before the addition of saline, but with salt loading, the Max EPA-fed SHRs showed a mean blood pressure increase of 21 mmHg relative to the EPA-fed SHR with access to water. Rats fed EPA showed impaired ability to generate serum thromboxane (TXB2) and in the groups with access to water, diminished excretion of urinary 6-keto-PGF1 alpha and PGE2. Salt loading increased prostanoid synthesis and excretion. Spontaneously hypertensive rats had greater serum TXB2 generating capacity than WKYs, but diminished urinary PGE2 excretion in those animals with access to water. The increased blood pressure observed in the salt-loaded SHR on the Max EPA-diet may be explained by reduced PG synthesis resulting in either mild sodium retention and/or increased vascular reactivity.

Topics: Animals; Blood Pressure; Body Weight; Coconut Oil; Dietary Fats; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Electrolytes; Fatty Acids; Fatty Acids, Unsaturated; Hydrogenation; Male; Plant Oils; Prostaglandins; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Sodium Chloride; Thromboxanes