Regulation of Redox Profile and Genomic Instability by Physical Exercise Contributes to Neuroprotection in Mice with Experimental Glioblastoma.

Glioblastoma (GBM) is an aggressive, common brain cancer known to disrupt redox biology, affecting behavior and DNA integrity. Past research remains inconclusive. To further understand this, an investigation was conducted on physical training's effects on behavior, redox balance, and genomic stability in GBMA models. Forty-seven male C57BL/6J mice, 60 days old, were divided into GBM and sham groups (n = 15, n = 10, respectively), which were further subdivided into trained (Str, Gtr; n = 10, n = 12) and untrained (Sut, Gut; n = 10, n = 15) subsets. The trained mice performed moderate aerobic exercises on a treadmill five to six times a week for a month while untrained mice remained in their enclosures. Behavior was evaluated using open-field and rotarod tests. Post training, the mice were euthanized and brain, liver, bone marrow, and blood samples were analyzed for redox and genomic instability markers. The results indicated increased latency values in the trained GBM (Gtr) group, suggesting a beneficial impact of exercise. Elevated reactive oxygen species in the parietal tissue of untrained GBM mice (Gut) were reduced post training. Moreover, Gtr mice exhibited lower tail intensity, indicating less genomic instability. Thus, exercise could serve as a promising supplemental GBM treatment, modulating redox parameters and reducing genomic instability.

Physical Training Protects Against Brain Toxicity in Mice Exposed to an Experimental Model of Glioblastoma.

Glioma 261 (Gl261) cell-mediated neurotoxicity has been reported in previous studies examining glioblastoma (GBM), and the effects of physical exercise (PE) on this neurotoxicity have been poorly investigated. This study aimed to evaluate the effects of a PE program in animals with experimental GBM. Male C57BL/6J mice were randomized into sham or GBM groups and subjected to a PE program for four weeks. Gl261 cells were administered into the intraventricular region at 48 h after the last exercise session. Body weight, water and feed consumption, and behavior were all evaluated for 21 days followed by euthanasia. The right parietal lobe was removed for the analysis of glial fibrillary acidic protein (GFAP), epidermal growth factor receptor (EGFR), vimentin, C-myc, nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1ß), interleukin 6 (IL-6), hydrogen peroxide, the glutathione system, and oxidative damage to proteins. The results revealed changes in the behavioral patterns of the trained animals, and no anatomopathological changes were observed in response to PE training. In contrast, animals with GBM subjected to PE exhibited lower immunoexpression of c-MYC, vimentin, and GFAP. Although experimental GBM altered the redox profile and inflammatory mediators, no significant alterations were observed after PE. In conclusion, our data provide consistent evidence of the relationship between PE and the improvement of tumorigenic parameters against the neurotoxicity of GL261 cells.

Effect of watercress extract supplementation on lipid profile and oxidative stress markers in overweight people with physical disability: A randomized, double-blind, and placebo-controlled trial.

Studies have demonstrated that diet rich in cruciferous vegetables of the Brassicaceae family can reduce the risk of cardiovascular diseases and oxidative stress levels. Nasturtium officinale (Brassicaceae), commonly known as watercress is a perennial dicotyledonous plant usually found close to water. Although previous investigations have demonstrated the beneficial effects of watercress on hypercholesterolemia in animal studies, until now no such studies have been conducted with humans, up to this time. This study aimed to investigate whether overweight individuals were able to improve or maintain their serum lipid and oxidative stress markers when given standardized extract of Nasturtium officinale (SENO) as a supplement. This was a randomized, double-blind, and placebo-controlled trial conducted over 5 weeks. Thirty-four overweight people with physical disabilities were selected randomly to participate in this study and then they were assigned randomly to two groups, one treated with 750 mg//kg/d of SENO and the other treated with 750 mg/kg/d of placebo. The results indicated that SENO caused a significant improvement in the levels of low-density lipoprotein cholesterol, creatinine, and lipid peroxidation. However, SENO did not cause a significant statistical change in total serum cholesterol, triacylglycerol, and high-density lipoprotein levels; catalase, superoxide dismutase, creatinine, alanine aminotransferase, aspartate aminotransferase, and urea parameters. The present data might provide supportive evidence that SENO did not cause any harm and positively affected low-density lipoprotein cholesterol profile and creatinine as well as lipid peroxidation levels in the participants. Nevertheless, further studies are suggested to clarify the results presented in this clinical trial.

Fish oil supplementation enhances colon recovery after experimental colitis.

INTRODUCTION: Fish oil (FO) has an anti-inflammatory and pro-resolution activity and it has been used to restore physiological disturbances on inflammatory conditions. Here, we investigate whether FO supplementation could, acutely, prevent or restore inflammatory damages on experimental colitis. METHODS: Wistar rats orally received 2 g.kg-1.day-1 of FO for 30 days before induction of experimental colitis. Specimens were collected on the 2nd and 7th days after colitis-induction and intestinal mucus, inflammatory activity and colon integrity were determined. RESULTS: Experimental colitis did cause colon disruption and FO, acutely, did not prevent the loss of intestinal and fecal mucus, neither the increase of inflammatory activity and intestinal permeability. On the 7th day of colitis, FO soften the perturbations of experimental colitis, increasing histological and fecal mucus and, also decreased inflammatory activity, but this was not accompanied by intestinal permeability. CONCLUSION: FO did not protect, acutely, intestinal damages from experimental colitis, but at long run promotes higher intestinal recovery.

Does Oil Rich in Alpha-Linolenic Fatty Acid Cause the Same Immune Modulation as Fish Oil in Walker 256 Tumor-Bearing Rats?

OBJECTIVE: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. METHODS: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. RESULTS: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. CONCLUSIONS: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.

Wound healing treatment by high frequency ultrasound, microcurrent, and combined therapy modifies the immune response in rats

BACKGROUND: Therapeutic high-frequency ultrasound, microcurrent, and a combination of the two have been used as potential interventions in the soft tissue healing process, but little is known about their effect on the immune system. OBJECTIVE: To evaluate the effects of therapeutic high frequency ultrasound, microcurrent, and the combined therapy of the two on the size of the wound area, peritoneal macrophage function, CD4+ and CD8+, T lymphocyte populations, and plasma concentration of interleukins (ILs). METHOD: Sixty-five Wistar rats were randomized into five groups, as follows: uninjured control (C, group 1), lesion and no treatment (L, group 2), lesion treated with ultrasound (LU, group 3), lesion treated with microcurrent (LM, group 4), and lesion treated with combined therapy (LUM, group 5). For groups 3, 4 and 5, treatment was initiated 24 hours after surgery under anesthesia and each group was allocated into three different subgroups (n=5) to allow for the use of the different therapy resources at on days 3, 7 and 14 Photoplanimetry was performed daily. After euthanasia, blood was collected for immune analysis. RESULTS: Ultrasound increased the phagocytic capacity and the production of nitric oxide by macrophages and induced the reduction of CD4+ cells, the CD4+/CD8+ ratio, and the plasma concentration of IL-1β. Microcurrent and combined therapy decreased the production of superoxide anion, nitric oxide, CD4+-positive cells, the CD4+/CD8+ ratio, and IL-1β concentration. CONCLUSIONS: Therapeutic high-frequency ultrasound, microcurrent, and combined therapy changed the activity of the innate and adaptive immune system during healing process but did not accelerate the closure of the wound.

Wound healing treatment by high frequency ultrasound, microcurrent, and combined therapy modifies the immune response in rats.

BACKGROUND: Therapeutic high-frequency ultrasound, microcurrent, and a combination of the two have been used as potential interventions in the soft tissue healing process, but little is known about their effect on the immune system. OBJECTIVE: To evaluate the effects of therapeutic high frequency ultrasound, microcurrent, and the combined therapy of the two on the size of the wound area, peritoneal macrophage function, CD4+ and CD8+, T lymphocyte populations, and plasma concentration of interleukins (ILs). METHOD: Sixty-five Wistar rats were randomized into five groups, as follows: uninjured control (C, group 1), lesion and no treatment (L, group 2), lesion treated with ultrasound (LU, group 3), lesion treated with microcurrent (LM, group 4), and lesion treated with combined therapy (LUM, group 5). For groups 3, 4 and 5, treatment was initiated 24 hours after surgery under anesthesia and each group was allocated into three different subgroups (n=5) to allow for the use of the different therapy resources at on days 3, 7 and 14 Photoplanimetry was performed daily. After euthanasia, blood was collected for immune analysis. RESULTS: Ultrasound increased the phagocytic capacity and the production of nitric oxide by macrophages and induced the reduction of CD4+ cells, the CD4+/CD8+ ratio, and the plasma concentration of IL-1ß. Microcurrent and combined therapy decreased the production of superoxide anion, nitric oxide, CD4+-positive cells, the CD4+/CD8+ ratio, and IL-1ß concentration. CONCLUSIONS: Therapeutic high-frequency ultrasound, microcurrent, and combined therapy changed the activity of the innate and adaptive immune system during healing process but did not accelerate the closure of the wound.

α-Linolenic Fatty Acid Supplementation Decreases Tumor Growth and Cachexia Parameters in Walker 256 Tumor-Bearing Rats.

Fish oil (FO) has been shown to affect cancer cachexia, tumor mass, and immunity cell. n-3 PUFA, specifically α-linolenic fatty acid (ALA), has controversial effects. We investigated this in nontumor-bearing Wistar rats fed regular chow (C), fed regular chow and supplemented with FO or Oro Inca oil (OI), and Walker 256 tumor-bearing rats fed regular chow (W), fed regular chow and supplemented with FO (WFO) or OI (WOI). Rats were supplemented (1g/kg body weight/day) during 4 wk and then the groups tumor-bearing were inoculated with Walker 256 tumor cells suspension and 14 days later the animals were killed. WFO increased EPA fivefold and DHA 1.5-fold in the tumor tissue compared to W (P < 0.05). OI supplementation increased of threefold of ALA when compared to W (P < 0.05). Tumor mass in WFO and OI was of 2.3-fold lower, as well as tumor cell proliferation of 3.0-fold tumor tissue lipoperoxidation increased of 76.6% and cox-2 expression was 20% lower. Cachexia parameters were attenuate, blood glucose (25% higher), Triacylglycerolemia (50% lower), and plasma TNF-α (65% lower; P < 0.05) and IL-6 (62.5% lower). OI, rich in ALA, caused the same effect on cancer as those seen in FO.

Glucose intolerance induced by glucocorticoid excess is further impaired by co-administration with ß-hydroxy-ß-methylbutyrate in rats.

Glucocorticoid (GC) excess alters glucose homeostasis and promotes modifications in murinometric and anthropometric parameters in rodents and humans, respectively. ß-hydroxy-ß-methylbutyrate (HMB), a leucine metabolite, has been proposed as a nutritional strategy for preventing muscle wasting, but few data regarding its effects on glucose homeostasis are available. Here, we analyzed whether the effects of GC excess on glucose homeostasis may be attenuated or exacerbated by the concomitant ingestion of HMB. Adult Wistar rats (90-days-old) were assigned to four groups: (1) vehicle treated (Ctl), (2) dexamethasone (DEX) treated (Dex), (3) HMB treated (Hmb), and (4) DEX plus HMB treated (DexHmb). Dex groups received DEX (1 mg·kg body weight (BW)(-1), intraperitoneal) for 5 consecutive days. HMB groups ingested HMB (320 mg·kg BW(-1), oral gavage) for the same 5 days. HMB ingestion did not attenuate the effects of DEX on food intake and body weight loss, changes in masses of several organs, insulin resistance, and glucose intolerance (p > 0.05). In fact, in DexHmb rats, there was increased fasting glycemia and exacerbated glucose intolerance with the main effect attributed to DEX treatment (p < 0.05). HMB exerted no attenuating effect on plasma triacylglycerol levels from DexHmb rats, but it seems to attenuate the lipolysis induced by ß-adrenergic stimulation (20 µmol·L(-1) isoproterenol) in fragments of retroperitoneal adipose tissue from DexHmb rats. Therefore, HMB does not attenuate the diabetogenic characteristics of GC excess. In fact, the data suggest that HMB may exacerbate GC-induced glucose intolerance.

Fish oil supplementation for two generations increases insulin sensitivity in rats.

We investigated the effect of fish oil supplementation for two consecutive generations on insulin sensitivity in rats. After the nursing period (21 days), female rats from the same prole were divided into two groups: (a) control group and (b) fish oil group. Female rats were supplemented with water (control) or fish oil at 1 g/kg body weight as a single bolus for 3 months. After this period, female rats were mated with male Wistar rats fed on a balanced chow diet (not supplemented). Female rats continued to receive supplementation throughout gestation and lactation periods. The same treatment was performed for the next two generations (G1 and G2). At 75 days of age, male offspring from G1 and G2 generations from both groups were used in the experiments. G1 rats did not present any difference with control rats. However, G2 rats presented reduction in glycemia and lipidemia and improvement in in vivo insulin sensitivity (model assessment of insulin resistance, insulin tolerance test) as well as in vitro insulin sensitivity in soleus muscle (glucose uptake and metabolism). This effect was associated with increased insulin-stimulated p38 MAP kinase phosphorylation and lower n-6/n-3 fatty acid ratio, but not with activation of proteins from insulin signaling (IR, IRS-1 and Akt). Global DNA methylation was decreased in liver but not in soleus muscle. These results suggest that long-term fish oil supplementation improves insulin sensitivity in association with increased insulin-stimulated p38 activation and decreased n-6:n-3 ratio in skeletal muscle and decreased global DNA methylation in liver.

Fish oil supplementation improves neutrophil function during cancer chemotherapy.

Cancer chemotherapy is associated with neutropenia and impaired neutrophil function. This study aimed to investigate whether supplementation with low dose fish oil (FO), providing n-3 polyunsaturated fatty acids, in cancer patients receiving chemotherapy after surgical tumor (mainly gastrointestinal) removal is able to improve the function of blood neutrophils. Patients (n = 38) receiving chemotherapy (5-fluorouracil and leucovorin) were randomized into two groups; one group (control) did not receive a supplement, while the other group (FO) received 2 g FO/day for 8 weeks; the FO provided 0.3 g eicosapentaenoic acid plus 0.4 g docosahexaenoic acid per day. Patients in the control group lost an average of 2.5 kg of weight over the 8 weeks of the study. The number of blood polymorphonuclear cells (PMNC), mainly neutrophils, and their functions (phagocytosis and hydrogen peroxide production) decreased in the control group (average decreases of approximately 30, 45 and 17%, respectively). FO prevented these decreases and actually increased body weight (average of 1.7 kg weight gain; p < 0.002 vs. control group), PMNC number (average 29% increase), phagocytosis (average 14% increase) and superoxide production (average 28% increase). FO may be useful in preventing chemotherapy-induced decline in neutrophil number and function.

ß-Hydroxy-ß-methylbutyrate modifies human peripheral blood mononuclear cell proliferation and cytokine production in vitro.

OBJECTIVE: The main objective was to investigate the potential immunomodulatory effects of ß-hydroxy-ß-methylbutyrate (HMB) in human cells. METHODS: Peripheral blood mononuclear cells were isolated from the blood of eight volunteers and assayed for proliferation, cell cycle progression, surface expression of CD25, intracellular expression of pERK1/2, and cytokine production after in vitro exposure to a range of HMB concentrations (0.1 to 10 mM). RESULTS: Above 1 mM, HMB decreased the extent of proliferation normally observed after stimulation by concanavalin A. The decrease was evident at 10 mM HMB, when the proliferation index was 50% reduced when compared with the absence of HMB. Cell cycle analysis demonstrated an increase in the proportion of cells at the G0-G1 phase at 10 mM HMB. CD25 and pERK1/2 expression were not related to the observed effect on proliferation. HMB affected the concentrations of all five cytokines measured following stimulation. Tumor necrosis factor-α concentration in the culture medium was reduced by ~35% at all HMB concentrations. Th1/Th2 cytokine production was modified toward a Th2 profile when HMB was at 1 or 10 mM. Thus, HMB at 10 mM impairs lymphocyte proliferation and progression through the cell cycle. The lowest concentration used here (0.1 mM) exerted some actions on cytokine production, including decreasing TNF-α production, but not on proliferation and cell cycle progression. CONCLUSION: HMB may be a useful agent to consider for modulation of immune function in specific situations.

Walker-256 tumor growth is inhibited by the independent or associative chronic ingestion of shark liver and fish oil: a response linked by the increment of peritoneal macrophages nitrite production in Wistar rats.

Fish oil (FO) is widely known by its capacity to positively modulate immune parameters and decrease the growth of some tumors. Despite the enormous number of studies addressing the effects of FO, there are few reports showing similar results using other marine sources of lipid compounds with biologic importance. This study aimed to compare the effects of shark liver oil (SLO), which is a source of omega-3 fatty acids and alkylglycerols, with those obtained with FO administration, or the association of both, on tumor growth and the innate immune system in Walker-256 tumor-bearing rats. Beginning at 21 days of age, Wistar rats were fed regular chow and/or FO and/or SLO supplement (1 g/kg body weight per day) for 14 weeks. Walker-256 tumor cells were inoculated on the 90th day. As expected, 14 days after inoculation, rats fed with FO presented tumor weights that were 50% lower than the control tumors (P < .05). The association of both FO and SLO and ingestion of SLO alone also reached the same reduction level. Except for adhesion, all macrophage parameters assayed were 200% higher in rats fed with FO and those supplemented with both FO and SLO compared with control rats. Only reactive nitrogen species production was increased by SLO. These results suggest that SLO might also have indirect antitumor properties. Conversely, there were no additive effects when SLO was administered with FO. Therefore, SLO is another marine compound with in vivo antitumor effects, but its action mechanisms seem not to be related to major modifications on macrophage function.

Lymphocytes transfer [(14)C]-labeled fatty acids to skeletal muscle in culture; modulation by exercise.

Previous studies have shown that lipids are transferred from lymphocytes (Ly) to different cell types including macrophages, enterocytes, and pancreatic beta cells in co-culture. This study investigated whether [(14)C]-labeled fatty acids (FA) can be transferred from Ly to skeletal muscle (SM), and the effects of exercise on such phenomenon. Ly obtained from exercised (EX) and control (C) male Wistar rats were preloaded with the [(14)C]-labeled free FA palmitic (PA), oleic (OA), linoleic (LA), or arachidonic (AA). Radioactively loaded Ly were then co-cultured with SM from the same Ly donor animals. Substantial amounts of FA were transferred to SM being the profile PA = OA > AA > LA to the C group, and PA > OA > LA > AA to the EX group. These FA were incorporated predominantly as phospholipids (PA = 66.75%; OA = 63.09%; LA = 43.86%; AA = 47.40%) in the C group and (PA = 63.99% OA = 52.72%; LA = 55.99%; AA = 63.40%) in the EX group. Also in this group, the remaining radioactivity from AA, LA, and OA acids was mainly incorporated in structural and energetic lipids. These results support the hypothesis that Ly are able to export lipids to SM in co-culture. Furthermore, exercise modulates the lipid transference profile, and its incorporation on SM. The overall significance of this phenomenon in vivo remains to be elucidated.

Dietary supplementation with soybean lecithin increases pulmonary PAF bioactivity in asthmatic rats.

The prevalence of asthma has risen over the last few decades, and some studies correlate this with the greater consumption of polyunsaturated fatty acids (PUFAs). Dietary PUFAs are known to increase the susceptibility of biological structures to lipid peroxidation, a process by which platelet-activating factor (PAF)-like lipids can be generated. These lipids functionally mimic the bioactivity of PAF, a potent proinflammatory mediator that exerts several deleterious effects on asthma. Thus, this work aimed to investigate if dietary supplementation with soybean lecithin (SL), a source of PUFAs, increases lipid peroxidation and PAF bioactivity in lungs of asthmatic Wistar rats. Animals were separated into groups: control, supplemented, asthmatic, asthmatic supplemented with SL (2 g/kg body weight), asthmatic supplemented with SL (2 g/kg body weight) and DL-alpha-tocopheryl acetate (100 mg/kg body weight). Asthmatic inflammation increased pulmonary lipid peroxidation, PAF bioactivity, alveolar-capillary barrier permeability and production of nitric oxide. In asthmatics, dietary supplementation with SL promoted an increase in pulmonary lipid peroxidation and PAF bioactivity, and an increase in the permeability of the alveolar-capillary barrier. Moreover, the treatment of asthmatic rats with DL-alpha-tocopheryl acetate inhibited the lipid peroxidation and decreased the PAF bioactivity. Therefore, the increase in pulmonary PAF bioactivity in asthmatic individuals elicited by the dietary supplementation with SL probably involves the generation of PAF-like lipids. This finding suggests that PAF-like lipids may account for the deleterious effects of dietary PUFAs on asthma.

Effect of fish oil supplementation for two generations on changes of lymphocyte function induced by Walker 256 cancer cachexia in rats.

Fish oil supplementation has been shown to improve the cachectic state of tumor-bearing animals and humans. Our previous study showed that fish oil supplementation (1 g per kg body weight per day) for 2 generations had anticancer and anticachetic effects in Walker 256 tumor-bearing rats as demonstrated by reduced tumor growth and body weight loss and increased food intake and survival. In this study, the effect of fish oil supplementation for 2 generations on membrane integrity, proliferation capacity, and CD4/CD8 ratio of lymphocytes isolated from mesenteric lymph nodes, spleen, and thymus of Walker 256 tumor-bearing animals was investigated. We also determined fish oil effect on plasma concentration and ex vivo production of cytokines [tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-6, and IL-10]. Lymphocytes from thymus of tumor-bearing rats presented lower viability, but this change was abolished by fish oil supplementation. Tumor growth increased proliferation of lymphocytes from all lymphoid organs, and fish oil supplementation abolished this effect. Ex vivo production of TNF-alpha and IL-6 was reduced in supplemented animals, but IL-4 and IL-10 secretion was stimulated in both nontumor and tumor-bearing rats. IL-10 and IFN-gamma plasma levels was also decreased in supplemented animals. These results suggest that the anticachetic effects of fish oil supplementation for a long period of time (2 generations) in Walker 256 tumor-bearing rats may be associated to a decrease in lymphocyte function as demonstrated by reduced viability, proliferation capacity, and cytokine production.

Soy lecithin supplementation alters macrophage phagocytosis and lymphocyte response to concanavalin A: a study in alloxan-induced diabetic rats.

Dietary soy lecithin supplementation decreases hyperlipidemia and influences lipid metabolism. Although this product is used by diabetic patients, there are no data about the effect of soy lecithin supplementation on the immune system. The addition of phosphatidylcholine, the main component of lecithin, to a culture of lymphocytes has been reported to alter their function. If phosphatidylcholine changes lymphocyte functions in vitro as previously shown, then it could also affect immune cells in vivo. In the present study, the effect of dietary soy lecithin on macrophage phagocytic capacity and on lymphocyte number in response to concanavalin A (ConA) stimulation was investigated in non-diabetic and alloxan-induced diabetic rats. Supplementation was carried out daily with 2 g kg(-1) b.w. lecithin during 7 days. After that, blood was drawn from fasting rats and peritoneal macrophages and mesenteric lymph node lymphocytes were collected to determine the phospholipid content. Plasma triacylglycerol (TAG), total and HDL cholesterol and glucose levels were also determined. Lymphocytes were stimulated by ConA. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) dye reduction method and flow cytometry were employed to evaluate lymphocyte metabolism and cell number, respectively. Soy lecithin supplementation significantly increased both macrophage phagocytic capacity (+29%) in non-diabetic rats and the lymphocyte number in diabetic rats (+92%). It is unlikely that plasma lipid levels indirectly affect immune cells, since plasma cholesterol, TAG, or phospholipid content was not modified by lecithin supplementation. In conclusion, lymphocyte and macrophage function were altered by lecithin supplementation, indicating an immunomodulatory effect of phosphatidylcholine.

Glucose metabolism by lymphocytes, macrophages, and tumor cells from Walker 256 tumor-bearing rats supplemented with fish oil for one generation.

Here we investigated the effect of lifelong supplementation of the diet with coconut fat (CO, rich in saturated fatty acids) or fish oil (FO, rich in n-3 polyunsaturated fatty acids) on tumor growth and lactate production from glucose in Walker 256 tumor cells, peritoneal macrophages, spleen, and gut-associated lymphocytes. Female Wistar rats were supplemented with CO or FO prior to mating and then throughout pregnancy and gestation and then the male offspring were supplemented from weaning until 90 days of age. Then they were inoculated subcutaneously with Walker 256 tumor cells. Tumor weight at 14 days in control rats (those fed standard chow) and CO supplemented was approximately 30 g. Supplementation of the diet with FO significantly reduced tumor growth by 76%. Lactate production (nmol h(-1) mg(-1) protein) from glucose by Walker 256 cells in the group fed regular chow (W) was 381.8 +/- 14.9. Supplementation with coconut fat (WCO) caused a significant reduction in lactate production by 1.6-fold and with fish oil (WFO) by 3.8-fold. Spleen lymphocytes obtained from W and WCO groups had markedly increased lactate production (553 +/- 70 and 635 +/- 150) when compared to non-tumor-bearing rats ( approximately 260 +/- 30). FO supplementation reduced significantly the lactate production (297 +/- 50). Gut-associated lymphocytes obtained from W and WCO groups increased lactate production markedly (280 +/- 31 and 276 +/- 25) when compared to non-tumor-bearing rats ( approximately 90 +/- 18). FO supplementation reduced significantly the lactate production (168 +/- 14). Lactate production by peritoneal macrophages was increased by tumor burden but there was no difference between the groups fed the various diets. Lifelong consumption of FO protects against tumor growth and modifies glucose metabolism in Walker tumor cells and lymphocytes but not in macrophages.

Endogenous opioids: role in prostaglandin-dependent and -independent fever.

This study evaluated the participation of mu-opioid-receptor activation in body temperature (T(b)) during normal and febrile conditions (including activation of heat conservation mechanisms) and in different pathways of LPS-induced fever. The intracerebroventricular treatment of male Wistar rats with the selective opioid mu-receptor-antagonist cyclic d-Phe-Cys-Try-d-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP; 0.1-1.0 microg) reduced fever induced by LPS (5.0 microg/kg) but did not change T(b) at ambient temperatures of either 20 degrees C or 28 degrees C. The subcutaneous, intracerebroventricular, and intrahypothalamic injection of morphine (1.0-10.0 mg/kg, 3.0-30.0 microg, and 1-100 ng, respectively) produced a dose-dependent increase in T(b). Intracerebroventricular morphine also produced a peripheral vasoconstriction. Both effects were abolished by CTAP. CTAP (1.0 microg icv) reduced the fever induced by intracerebroventricular administration of TNF-alpha (250 ng), IL-6 (300 ng), CRF (2.5 microg), endothelin-1 (1.0 pmol), and macrophage inflammatory protein (500 pg) and the first phase of the fever induced by PGF(2alpha) (500.0 ng) but not the fever induced by IL-1beta (3.12 ng) or PGE(2) (125.0 ng) or the second phase of the fever induced by PGF(2alpha). Morphine-induced fever was not modified by the cyclooxygenase (COX) inhibitor indomethacin (2.0 mg/kg). In addition, morphine injection did not induce the expression of COX-2 in the hypothalamus, and CTAP did not modify PGE(2) levels in cerebrospinal fluid or COX-2 expression in the hypothalamus after LPS injection. In conclusion, our results suggest that LPS and endogenous pyrogens (except IL-1beta and prostaglandins) recruit the opioid system to cause a mu-receptor-mediated fever.

Glutamine concentration and immune response of spinal cord-injured rats.

BACKGROUND/OBJECTIVES: Glutamine plays a key role in immune response. Spinal cord injury (SCI) leads to severe loss of muscle mass and to a high incidence of infections. This study investigated the acute effect of SCI (2 and 5 days) on the plasma glutamine and skeletal muscle concentrations and immune responses in rats. METHODS: A total of 29 adult male Wistar rats were divided as follows: control (C; n = 5), sham-operated (S2; n = 5) and spinal cord-transected (T2; n = 7). They were killed on day 2 after surgery/transection (acute phase). Another set was sham-operated (S5; n = 5), spinal cord-transected (T5; n = 7), and killed at day 5 after surgery/transection (secondary phase). Blood was collected; the white portion of the epitrochlearis and gastrocnemius muscles and the red portion of soleus muscles were dissected to measure the glutamine concentration. Gut-associated lymphocytes and peritoneal macrophages were obtained for immune parameters measurements. RESULTS: Glutamine concentration in the plasma, gastrocnemius, and soleus muscles in rats with SCI were significantly reduced but not in the epitrochlearis muscle in the acute (2 days) and secondary (5 days) phases. Phagocytic response was reduced in the acute phase but increased in the secondary phase in rats with SCI. Superoxide production, on the other hand, was significantly increased at days 2 and 5 after SCI, and CD8+ lymphocytes subset decreased significantly on days 2 and 5. CONCLUSIONS: Our results showed reduction in plasma glutamine and skeletal muscle concentrations after spinal cord transection. They also suggest that SCI and glutamine reduction contribute to an alteration in immune competence.