Immune Response In Rats Research Articles

Lymphoid follicle antigen (Ag) delivery and enhanced rodent humoral immune responses mediated by Ag-containing PEGylated liposomes

Antigen (Ag) delivery to lymphoid follicles is important in achieving adaptive immunity. We recently developed a novel two-step Ag delivery system that efficiently induces cellular immune responses to Ags in mice by using priming intravenous (i.v.) injections of empty PEGylated liposomes (PEG-Lip) followed 3 days later by Ag-entrapped PEG-Lip (Ag-PEG-lip). In this study, we looked for humoral immune responses in rats and mice with IgG production specific to the encapsulated Ags. We observed that initial i.v. injections of empty PEG-Lip triggered accumulation of subsequent doses ovalbumin-PEG-Lip (OVA-PEG-lip) in splenic follicles and enhanced IgG production against OVA in both rats and mice. Anti-OVA IgG production was diminished by inhibition of splenic follicular accumulation of OVA-PEG-Lip by fingolimod (FTY720), which inhibits lymphocyte egress from lymphoid tissues. Thisindicates that the follicular accumulation of Ags that we observed is an indispensable and unique step in the production of anti-OVA IgG. Interestingly, in BALB/c nude mice, which are T cell deficient, a high follicular accumulation of OVA-PEG-Lip was observed, but anti-OVA IgG production was not observed. This suggests that T cells are also indispensable for the induction of cellular immune responses by our two-step immunization procedure. Our unique Ag delivery platform, which efficiently delivers Ags to splenic follicles, may be a useful technique for the enhancement of cellular immunity, as well as humoral immunity. Further experimental evaluation should be undertaken in relevant animal models in order for efficacy, safety and immunological correlates to be determined.

Interleukin IL-5 alleviates sepsis-induced acute lung injury by regulating the immune response in rats

ABSTRACT To study the effect of IL-5 on the immune response and lung injury in rats with sepsis. We constructed a rat model of sepsis by cecal ligation and puncture (CLP). The rats were randomly divided into the control group, the sham group, the CLP group and the IL-5 group, with 6 rats in each group. With the induction of CLP, the lung tissue of rats was severely injured, and the water content of lung tissue was significantly increased. Moreover, the ratio of CD4+/CD8+ was significantly decreased and Th1/Th2 was significantly increased in the peripheral blood. The content of IL-6, TNF-α, and HMGB1 was found to be increased in the CLP group. However, with the injection of IL-5, the degree of lung tissue injury in CLP rats was alleviated and the water content of lung tissue was significantly reduced. The ratio of CD4+/CD8+ was increased and Th1/Th2 was significantly down-regulated in the peripheral blood and the levels of IL-6, TNF-α, and HMGB1 in serum were significantly decreased. In conclusion, IL-5 can alleviate lung injury by regulating the immune response and inhibiting the systemic inflammatory response induced by sepsis.

Donepezil protects glycerol-induced acute renal failure through the cholinergic anti-inflammatory and nitric oxide pathway in rats

Objectives Inflammation as well as oxygen metabolite play important roles in renal injury during pathogenesis of rhabdomyolysis induced myoglobinuric acute renal failure (ARF). The aim of this study was to investigate the protective effects of donepezil on immune responses in rats with glycerol-induced ARF. Methods Sixty male rats were randomly divided into six groups, the rats were given normal saline (10 ml/kg, i.m.), glycerol (50%, 10 ml/kg, i.m.), glycerol plus dexamethasone (0.1 mg/kg, i.g.), and glycerol plus donepezil (1, 5 and 10 mg/kg, i.g.) respectively. After two weeks of glycerol injections, the kidney tissues and blood samples were harvested for future biochemical and pathology analysis. The levels of creatinine (Cr) and urea nitrogen (BUN) in plasma, the content of malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) activity, total nitric oxide synthase (TNOS), inducible nitric oxide synthase (iNOS), endothelial NO synthase (eNOS) were evaluated in renal tissues. In addition, interleukin-6 (IL-6), tumor necrosis factors-α (TNF-α) in renal tissues were also determined. Results Donepezil treatment protected rats from renal dysfunction in a dose-dependent manner and through the cholinergic anti-inflammatory pathway. Additionally, donepezil significantly reduced tubular damages, prevented neutrophil infiltration and decreased productions of the IL-6, TNF-α, nitric oxide content and oxidative damage. Conclusions These data indicate that donepezil exerts a protective anti-inflammatory effect during ARF through the cholinergic pathway and Nitric oxide pathway. In addition, this study could provide an opportunity to overcome the effect of surgical cholinergic denervation during kidney transplantation and other injury.

Peroxiredoxin 6 overexpression regulates adriamycin-induced myocardial injury, oxidative stress and immune response in rats.

BackgroundAdriamycin is an anthracycline drug used to treat a variety of tumors. Adriamycin has a much stronger affinity for myocardial tissue than other body tissues. Cancer patients treated with adriamycin are prone to toxic damage to heart tissue. Peroxiredoxin 6 (PRDX6) is a novel antioxidant enzyme in metabolic diseases, the aim of this study was to investigate the role of PRDX6 in myocardial injury.MethodsSixty male specific-pathogen-free Wistar rats were enrolled and divided equally into the control group (control), the Adriamycin group, the Adriamycin + empty vector lentivirus (Adriamycin + LV) group, and the Adriamycin + Peroxiredoxin 6 overexpression (Adriamycin + PRDX6) group. Western blot, reverse transcription-polymerase chain reaction (PCR), enzyme-linked immunosorbent assay, hematoxylin and eosin staining (HE) and immunohistochemistry were used in this research.ResultsThe myocardial tissues of the Adriamycin group had significantly lower expression levels of PRDX6 and PRDX6 mRNA than those of the control group, and the myocardial tissues of the Adriamycin + PRDX6 rats had significantly higher expression levels of PRDX6 and PRDX6 mRNA than those of the Adriamycin + LV group. Serum creatine kinase isoenzyme (CK-MB), myoglobin (Mb), cardiac troponin I (cTnI), myocardial injury, positive rate of caspase-3, B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) levels, malondialdehyde (MDA), lactate dehydrogenase (LDH), IL-1β, IL-6, inducible nitric oxide synthase (iNOS), and IL-4 proteins in the adriamycin-induced rats were significantly higher than those in the control group, while superoxide dismutase (SOD) activity was significantly lower than that in the control group. PRDX6 overexpression reversed the above results.ConclusionsPRDX6 overexpression can alleviate adriamycin-induced myocardial injury in rats, which may be related to oxidative stress regulation and the levels of inflammatory factors.

Safety of photosynthetic Synechococcus elongatus for in vivo cyanobacteria-mammalian symbiotic therapeutics.

SummaryThe cyanobacterium Synechococcus elongatus (SE) has been shown to rescue ischaemic heart muscle after myocardial infarction by photosynthetic oxygen production. Here, we investigated SE toxicity and hypothesized that systemic SE exposure does not elicit a significant immune response in rats. Wistar rats intravenously received SE (n = 12), sterile saline (n = 12) or E. coli lipopolysaccharide (LPS, n = 4), and a subset (8 SE, 8 saline) received a repeat injection 4 weeks later. At baseline, 4 h, 24 h, 48 h, 8 days and 4 weeks after injection, clinical assessments, blood cultures, blood counts, lymphocyte phenotypes, liver function tests, proinflammatory cytokines and immunoglobulins were assessed. Across all metrics, SE rats responded comparably to saline controls, displaying no clinically significant immune response. As expected, LPS rats exhibited severe immunological responses. Systemic SE administration does not induce sepsis or toxicity in rats, thereby supporting the safety of cyanobacteria–mammalian symbiotic therapeutics using this organism.

Analysis of RIG-I-mediated innate immune response in rats with Kidney-Yang Deficiency Syndrome and its change following Yougui pill administration

Kidney-Yang Deficiency Syndrome (KYDS) is closely bound up with the immune response of immunocompromised patients. The study is to investigate whether retinoic acid-inducible gene-I (RIG-I)-mediated innate immune responseparticipates in the development of KYDS in rats and evaluate the effect of Yougui pill (YGP) on the response in KYDS rats. KYDS rats were induced by intramuscular injection of hydrocortisone at the dose of 10 mg/kg/d for 15 days. YGP at concentrations of 2.43 g/kg/d and 4.86 g/kg/d were administered intragastrically to KYDS rats for 30 days. The results showed that the body weight, urinary 17-hydroxycorticosteroid (17-OHCS) level, spleen size and spleen index in KYDS rats were significantly decreased compared with healthy control rats, while YGP treatment reversed them towards normal level in a dose-dependent manner. Moreover, KYDS challenge not only strikingly increased the mRNA and protein expression levels of RIG-I, tripartite motif containing 25 (TRIM25), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) but also markedly enhanced the endogenous RIG-I polyubiquitination levels. Whereas, YGP treatment effectively reversed this tendency in a dose-dependent manner. In conclusion, these findings revealed that RIG-I-mediated innate immune response was closely bound up with the development of KYDS. And YGP exhibited certain anti-inflammatory effects on KYDS rats via inhibiting the RIG-I-mediated innate immune response.

Immune response in fluid therapy with crystalloids of different ratios or colloid for rats in haemorrhagic shock

This study investigated the association between different ratios of balanced salt based-crystalloid (PLASMA SOLUTION-A [CJ HealthCare, Seoul, Korea]) (the ratios of crystalloid for blood loss, 1:1, 1:2 and 1:3) or balanced salt-based colloid (VOLULYTE 6% [Fresenius Kabi, Germany]) (the ratio of colloid for blood loss, 1:1) to restore blood loss and immune response in rats with haemorrhagic shock. About 50% of total estimated blood volume was removed after anaesthesia. The fluid was administered for resuscitation after exsanguination, according to the type of fluid and the ratios of exsanguinated volume and fluid volume for resuscitation. After sacrifice, expression of immune cells in blood and tissues was evaluated. Histological analyses and syndecan-1 immunohistochemistry assays were performed on tissues. Endothelial damage according to syndecan-1 and cytokine levels in blood was also assessed. Fluid resuscitation with same, two-fold, or three-fold volumes of crystalloid, or same volume of colloid, to treat haemorrhagic shock in rats resulted in a similar increase in blood pressure. The expression of neutrophils in blood decreased significantly after colloid administration, compared to before exsanguination. Syndecan-1 expression increased after exsanguination and fluid resuscitation in all groups, without any significant difference. In conclusion, same volume of balanced salt-based crystalloid for blood loss was enough to restore BP at the choice of fluid for the management of haemorrhagic shock in the rats, compared with different ratios of crystalloid or same volume of colloid, on the aspect of immune response.

Serum Neurofilament Light Polypeptide is a Biomarker for Inflammation in Cerebrospinal Fluid Caused by Fine Particulate Matter

ABSTRACT Epidemiological and toxicological evidence indicates that fine particulate matter (PM2.5, particulate matter < 2.5 µm in aerodynamic diameter) causes cardiopulmonary toxicity; however, its neurotoxic effects remain unclear. The objective of this study was to investigate the role of the neurofilament light (NEFL) serum polypeptide in neurotoxicity. 6-month-old male Sprague Dawley (SD) rats were exposed to traffic-related PM1 (< 1 µm in aerodynamic diameter; 16.3 µg m–3) and gaseous pollutants (via high-efficiency particulate air, HEPA) for 3 and 6 months through a whole-body exposure system. According to our observations, the levels of interleukin (IL)-4, IL-10, and tumor necrosis factor (TNF)-α in the serum of the rats significantly increased (p < 0.05) after 3 months of exposure to PM1, whereas that of NEFL polypeptide significantly increased (p < 0.05) after 3 and 6 months of exposure. Additionally, increases in the IL-2, IL-6, IL-10, IL-17a, TNF-α, and interferon (IFN)-γ levels after 3 and/or 6 months of exposure to this pollutant (p < 0.05) were observed in the cerebrospinal fluid (CSF). In terms of their respective levels, the IL-6 correlated well with the CSF IL-2 and IL-10; the TNF-α correlated well with the CSF IL-6, IL-17a, TNF-α, and IFN-γ; and the NEFL polypeptide correlated well with the CSF IL-2, IL-4, IL-6, IL-10, IL-17a, TNF-α, and IFN-γ. In summary, systemic neuroinflammatory and immune responses in rats occurred after chronic exposure to PM1. Hence, NEFL polypeptide in serum may be a suitable biomarker for neurotoxicity caused by chronic exposure to this pollutant.

Иммуннологические и функциональные показатели крыс в модели принудительного плавания с применением потенциальных адаптогенов

The aim of the work was to study the effect of different doses of two ammonium compounds, chloride (ClA) and carbonate (CrA), as well as their combination with decaffeinated green tea extract (GTE) on the immunological parameters of the peripheral blood of rats during high-intensity exercise. Changes in the absolute and relative numbers of granulocytes, lymphocytes, natural killer cells, naive and mature effector cells, as well as some minor lymphocyte fractions, were established using a hematological analyzer and a flow cytometer one day after the end of the forced swimming cycle. Immunological parameters were compared with the duration of swimming on the last day of the cycle and with the average duration over 4 days of maximum load. The revealed changes indicate a high adaptogenic effectiveness of ClA at a dose of 20 mg/kg, since the animals of this group showed high functional results and they did not show signs of maladjustment and overstrain of immunity. CrA at a dose of 10 mg/kg led to a similar increase in functional results, but this was accompanied by the mobilization of the cellular immune response in rats. Doubling the dose of CrA led to a failure of adaptation. GTE did not contribute to an increase in physical performance, however, it had a positive effect on the state of the immune system of animals. The combination of GTE with ammonium salts did not lead to a significant improvement of the functional indicators, and, in general, had a negative effect on cellular immunity of animals of the GTE+CrA10 group, and, to a lesser extent, of the GTE+ClA20 group.

Behaviorally conditioned immunosuppression with cyclosporine A forms long lasting memory trace

Behaviorally conditioned taste avoidance (CTA) paradigms using the novel taste saccharin as a conditioned stimulus (CS) and the immunosuppressive drug cyclosporine A (CsA) as unconditioned stimulus (US) demonstrate learned suppression of immune functions. However, conditioned immune responses might decrease over time depending on the period between acquisition and retrieval (retention interval). Thus, the present study investigated whether and to what extent prolonged 14- and 30-days retention intervals affect conditioned behavioral (CTA) and immune responses in rats. Our findings demonstrate that conditioned animals displayed a marked CTA after 14 and 30 days upon CS re-exposure compared to control animals. More importantly, the production of the pro-inflammatory cytokine interferon (IFN)-γ was significantly suppressed in ex vivo anti-CD3 stimulated splenocytes of conditioned animals compared to controls at both time points. These findings document that CTA paradigms using the immunosuppressive drug CsA as US form long lasting memory traces of the learned behavioral and immune responses.

Gut microbiota modulation and immune boosting properties of prebiotic dragon fruit oligosaccharides

SummaryThis is the first report of the evaluation of suitability for consumption of dragon fruit oligosaccharide (DFO) and its efficacy on gut microbiota modulation and in boosting the gut immune response in rats. The DFO produced significantly increased faecal bifidobacteria and lactobacilli but decreased bacteroides and clostridia. The DFO also showed immune‐response boosting properties by significantly increasing the plasma immunoglobulin A and G concentrations. In addition, it was confirmed by blood chemistry analysis and histology of the colon of the rats that DFO is suitable for the consumption. These results suggest that DFO is a potentially novel source of prebiotic ingredients with probiotic‐stimulation and immune boosting properties.

Shenfu injection prolongs survival and protects the intestinal mucosa in rats with sepsis by modulating immune response.

The aim of present study was to assess the protective effects of Shenfu injection (SI) on the intestinal mucosa and its regulation on the mucosal immune responses in rats with sepsis. Sprague-Dawley rats were randomly divided into the sham, model, low-dose SI (LSF), and high-dose SI (HSF) groups. Sham animals underwent laparotomy only, whereas sepsis was modeled by cecal ligation and puncture in the remaining groups. At 2 h post-surgery, the LSF and HSF groups were intraperitoneally administered 5 and 20 mL/kg SI, respectively, whereas other animals with saline. At 12 h and 24 h post-surgery, eight rats per group were sacrificed, and blood and intestinal tissues were collected. The intestinal mucosa was analyzed by hematoxylin and eosin staining. Serum tumor necrosis factor (TNF)-α and interleukin (IL)-6 concentrations, as well as secretory immunoglobulin A (sIgA) content in the intestinal mucosa, were evaluated by enzyme-linked immunosorbent assay. CD3 and γδT lymphocytes were quantified by flow cytometry. Animal survival until 72 h was also recorded. Intestinal mucosal injury was significantly higher in model animals than in sham animals at postoperative 12 h and 24 h. Serum TNF-α and IL-6 levels were markedly increased, whereas sIgA and CD3 and γδT cell amounts were overtly decreased (p<0.01). The LSF and HSF rats showed lower mortality, intestinal mucosal injury, and serum TNF-α and IL-6 levels (p<0.05), as well as higher sIgA levels and CD3 and γδT cell amounts, than the model group (p<0.01), with a dose-dependent manner. SI dose-dependently prolongs survival and protects the intestinal mucosa in rats with sepsis, possibly through strengthening innate immunity instead of acquired immunity.

Evaluation of Immunomodulatory Potentials of The Leaves of Aquilaria malaccensis

In the present study the ethanolic extract of the leaves of Aquilaria malaccensis was evaluated for immunomodulatory effect against cyclophosphamide and sheep RBC induced immune response in rats. The oral acute toxicity study conducted with extract was found to be safe and non-toxic at a dose of 2000 mg/kg. The two doses of extract 200 mg/kg and 400 mg/kg, p.o. was tested for immunomodulatory effect by assessing immune response, haematological and biochemical parameters. Both the doses of extract treated groups of animals showed dose dependent, significant increase in immune response, haematological and biochemical parameters when compared with toxic control group of cyclophosphamide and sheep RBC induced immune suppression. The above observations support the findings that, the extract of Aquilaria malaccensis leaves was able to offer significant protection against cyclophosphamide and sheep RBC induced immune response probably by the presence of array of phytoconstituents and might be beneficial in the treatment of immune suppression related disorders.

Intracerebroventricular Aβ-Induced Neuroinflammation Alters Peripheral Immune Responses in Rats.

An important marker in Alzheimer disease (AD) is the abnormal production and accumulation of β-amyloid peptide (Aß) in brain. It produces oxidative damage in neurons and inflammation due to its neurotoxic properties. The present study was designed to investigate neuroinflammation (hippocampal levels of ROS, nitrite, TNF-α, and IL-1β), neurodegeneration (plaques andchromatolysisin hippocampus), and memory impairments (working memory and reference memory) and the effect of this neuroinflammation on some peripheral immunological parameters such as phagocytic activity of blood WBC and splenic polymorphonuclear (PMN)cells, leucocyte adhesion inhibition index (LAI), and cytotoxicity of splenic mononuclear cells (MNC) after the intracebroventricular injection of aggregated Aβ(1-42)in a4week study. The results showed that the hippocampal and serum levels of ROS, nitrite, TNF-α, and IL-1β were significantly higher in the AD animals along with increased chromatolysis and impairments of memory. There was also a significant increase in the phagocytic activity of splenic PMN and cytotoxicity of splenic MNC and a decrease in the phagocytic activity of blood WBC and LAI of splenic MNC in the Aβ(1-42)-injected AD rats compared to that of control and sham-operated rats. The results indicate that the increased levels of inflammatory markers in the hippocampus may provide signals to the periphery and can alter the systemic immune responses.

The airway inflammation induced by nasal inoculation of PM2.5 and the treatment of bacterial lysates in rats

Particulate matter (PM) is one of the most important environmental issues in China. This study aimed to explore the correlation between PM2.5 and airway inflammation in healthy rats. The PM2.5 group was given an intranasal instillation of PM2.5 suspension on 15 consecutive days, and each received oral saline from day 16 to 90. The BV intervention group was treated as the PM2.5 exposure group, except that BV instead of saline was given daily. A histopathologic examination was performed to evaluate the airway inflammation. The prevalence and function of Th1/Th2/Treg/Th17 cells were detected by flow cytometry and ELISA. The expression of AhR was detected by western blot and real-time PCR. We found that epithelial damage and increased infiltration of inflammatory cell were present in the airways after PM2.5 exposure; there was an immune imbalance of Th cells in the PM2.5 group; the expression of AhR was increased in the airways after PM2.5 exposure. In the PM2.5 + BV group, we demonstrated alleviated immune imbalance and reduced inflammatory cell infiltration in the airways. Our study showed that exposure to PM2.5 induced airway inflammation. The imbalance of Th1/Th2/Treg/Th17 in PM2.5-induced airway inflammation might be associated with activation of the AhR pathway. Oral BV reduces PM2.5-induced airway inflammation and regulates systemic immune responses in rats.

Influence of lactoferrin on immune response in rats intoxicated by diazinon

This study is done to evaluate the antioxidant effect of Lactoferrin (LF) on liver injury induced byDiazinon (DZN). Seventy five rats were divided into five groups, each group contains 15 rats;control (G1): (no treatments), Lactoferrin (G2): (LF, 100 mg/kg bw orally daily for 6 weeks),diazinon (G3): (DZN, 70 mg/kg bw orally, daily for 4 weeks), DZN +LF (G4): (DZN, 70 mg/kg bworally, daily for 4 weeks followed by LF, 100 mg/kg bw orally daily for 2 weeks, and (LF +DZN)group (G5): (LF, 100 mg/kg bw orally daily for seven weeks and DZN, 70 mg/kg bw for fourweeks only started at the second week of the experiment).Total leukocyte count (TLC) anddifferential leukocyte count (DLC) were checked in whole blood, cytokine IL-10, total proteins(TP)and protein electrophoresis were checked in serum. In comparison to control group, WBCs foundincreased significantly in DZN group(P<0.005) and IL-10, TP, albumin, and globulin were foundsignificantly decreased too. In comparison to DZN group, WBCs and IL-10, levels were foundsignificantly increased in (DZN+LF) group (P < 0.05), TP, albumin, and globulin levels were alsofound significantly increased (P < 0.05), WBCs found significantly decreased in (LF+DZN) groupand IL-10, TP, albumin, and globulin were found significantly increased too(P < 0.05) .

Sodium Hyaluronate/Chitosan Composite Microneedles as a Single-Dose Intradermal Immunization System.

Enhancing the immune response to vaccines and minimizing the need for repeated inoculations remain a challenge in clinical vaccination. This study developed a composite microneedle (MN), composed of a sodium hyaluronate (HA) tip and a chitosan base, for biphasic antigen release and evaluated the potential of using this MN formulation as an intradermal delivery system for single-dose vaccination. Upon skin insertion, the dissolvable HA tip dissolved within the skin for rapid release of the encapsulated antigens, thus priming the immune system, while the biodegradable chitosan base remained in the dermis for prolonged antigen release for 4 weeks, thus further boosting the stimulated immunity. Our results showed that a single immunization with the HA/chitosan MN containing ovalbumin (OVA) (100 μg × 1) stimulated both T helper type 1 (Th1) and Th2 immune responses in rats and induced considerably higher and more durable antibody responses than a traditional two-dose (100 μg OVA × 2) or double-dose (200 μg OVA × 1) subcutaneous vaccination. Thus, the proposed MN exerts strong adjuvanticity to greatly augment the antigen's immunogenicity. Moreover, given its unique rapid and sustained release properties, the HA/chitosan MN formulation has the potential to replace the conventional prime-boost regimen to serve as an effective single-dose vaccine formulation.

Effects of Dexamethasone on Contralateral Testicular Immune Response in Wistar Strain Rats with Unilateral Testicular Torsion

The aim of this study was to prove the effects of dexamethasone on immune responses in rats with testicular torsion. This was an experimental study with post test only control group design. In this study, 27 rats were randomly divided into 3 groups. In normal or sham group (CN) orchidectomy was performed on the right testis on day 14. The positive control group (CP) had testicular torsion for 10 h, then manual detorsion was performed after 4 h, and on day 14 orchidectomy was performed on ipsilateral and contralateral testes. The treatment group (N) had testicular torsion for 10 h and received 10 mg/kgBW dexamethasone subcutaneously 30 minutes before manual detorsion 4 hours later, and on day 14 orchidectomy was performed to ipsilateral and contralateral testes. The spermatogonium count was calculated based on the average number of intratubular seminiferous tubule section observed in contralateral testicular incision with Haematoxiliyn Eosin (HE) staining. IgG count was calculated based on the average number of extratubular seminiferous tubules observed at 5 contralateral testicular incision with immunohistochemical staining (IHC). The number of spermatogonia was significantly different between CN and CP, CN and N, and CP and N (p&lt;0.05). IgG production also showed significant differences between CN and CP, CN and N, as well as CP and N (p&lt;0.05). In conclusion, administration of dexamethasone provides a protective effect on spermatogonium count and IgG production on a 10-hour testicular torsion.

Effects of extract of Urtica dioica L. (stinging nettle) on the immune response of rats with severe malnutrition.

Background. Severe malnutrition is the main cause of immunodeficiency in children under five years old in areas of economic depression in developing countries, and it is associated with generalized atrophy of lymphoid tissues. Urtica dioica L. is a medicinal herb with multiple pharmacological functions; it acts as modulator of the immune response, stimulating the proliferation of T lymphocytes in vitro. Objective: To determine the ability of U. dioica L. to modulate the immune response of malnourished rats in the first 21 days of life. Methods: Third-degree malnutrition during lactation was induced by food competition, and treatment with U. dioica L was tested. Day-old Wistar rats were randomly assigned to three groups: a) the well-nourished group, b) the untreated malnourished group and c) the malnourished group treated with 0.2 g/mL U. dioica L. on days 14, 16, 18 and 20. On day 21, animals were euthanized, and the thymus, spleen, bone marrow and blood were obtained. Lymphocyte subpopulations were determined in the thymus and leukocyte subpopulations in blood. The total number of nucleated bone marrow cells was determined, and the proliferative capability of spleen lymphocytes from malnourished rats treated with U. dioica L. was compared to that of other groups. Results: U. dioica L. decreased CD4-CD8- lymphocytes and increased CD4+CD8+ lymphocytes in the thymus, while in the blood, it increased CD4+ cells, monocytes and total T lymphocytes. The proliferation of spleen cells was stimulated in the malnourished rats, and a decrease in total nucleated bone marrow cells was observed. An increase in the red blood cell count, hemoglobin and white blood cell count was observed in malnourished rats treated with Urtica dioica L. (p≤0.05). Conclusion: U. dioica L. had immunomodulatory effects since it promoted the differentiation of CD4-CD8- T lymphocytes towards CD4+CD8+ T lymphocytes and counteracted anemia and leucopenia associated with severe malnutrition. Key words: Severe malnutrition, immunodeficiency, immunomodulatory activity, T lymphocytes, Urtica dioica L.

The effects of oat bran and soy flour on humoral immune response in rats fed hypercholesterolaemic diets

Previous studies have demonstrated the immunological and hypercholesterolaemic effects of soluble dietary fibre and soy protein in rats. In this study, we evaluated the effects of oat bran and soy flour on humoral immune response in Wistar rats fed hypercholesterolaemic diets. Animals (6 groups) fed with different diets for 6 wks were inoculated twice with antigen (IgY). Plasma samples were collected after each inoculation and anti-IgY antibody (IgM, IgG1 and IgG2a) levels were evaluated by ELISA. Animals receiving 1% cholesterol presented an increase in anti-IgY IgG1 and a reduction in anti-IgY IgM and IgG2a relative to control animals. These effects were abrogated in animals fed 1% cholesterol and oat bran or oat bran+soy protein, but not in animals fed 1% cholesterol and soy protein. Diets containing 1% cholesterol resulted in hepatic lesions and higher liver and spleen relative weights, but did not affect lipid profile, weight gain, food intake, or food conversion efficiency. In conclusion, a high-cholesterol diet influences classes of antibodies produced in response to an antigen in a way that can be reversed by oat bran.