scholarly journals Pyrogenic and neuroinflammatory properties of zymosan and its potential as an alternative to live yeast in antipyretic drug testing

FACETS ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 162-182 ◽  
Author(s):  
Rachael Dangarembizi ◽  
Christoph D. Rummel ◽  
Joachim Roth ◽  
Kennedy H. Erlwanger ◽  
Michael T. Madziva ◽  
...  

Zymosan, an immunogenic cell wall extract of Saccharomyces cerevisiae has potential for use as an experimental pyrogen. However, the short-lived sickness responses noted with intraperitoneal and intra-articular administration of zymosan limits investigations on the long-term effectiveness of antipyretic drugs. Thus, there remains a need to establish an alternative route of zymosan administration that could induce long-lived fevers and inflammation. We injected male Sprague Dawley rats (250–300 g) subcutaneously with zymosan (30 or 300 mg/kg) or saline; n = 7–8. We measured core body temperature, cage activity, food intake and body mass for 24 h after injection. Blood and brain samples were collected at 2, 8, and 18 h after injection. Zymosan (300 mg/kg) induced fever, lethargy, and anorexia, which lasted for 24 h. Zymosan-induced sickness responses were accompanied by increased blood plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α; activation of inflammatory transcription factors (nuclear factor (NF) for IL-6, signal transducer and activator of transcription (STAT)-3, and NF-κB) in the hypothalamus and circumventricular organs; and increased hypothalamic mRNA expression of TNF-α, IL-1β, and IL-6 and rate-limiting enzymes for prostaglandin synthesis. Our results confirm the suitability of subcutaneous administration of zymosan for screening antipyretic and anti-inflammatory drugs in rats.

2021 ◽  
Vol 22 (18) ◽  
pp. 9828
Author(s):  
Aimee Y. Zhang ◽  
Katherine M. Marsh ◽  
Radhika Rastogi ◽  
Di Wu ◽  
Eric J. Charles ◽  
...  

Global hypothermia prolongs survival in rats with intraabdominal feculent sepsis by inhibiting inflammatory responses. We hypothesized that topical neck cooling (TNC) has similar benefits. Septic shock was induced by cecal ligation and incision (CLI) in Sprague Dawley rats. Rats were randomized to sham laparotomy, control with CLI, CLI with TNC, or vagotomy at the gastroesophageal junction before CLI and TNC. Two more groups underwent peritoneal washout with and without TNC two hours after CLI. TNC significantly lowered neck skin temperature (16.7 ± 1.4 vs. 30.5 ± 0.6 °C, p < 0.05) while maintaining core body normothermia. TNC rats recovered from anesthesia 70 min earlier than the control (p < 0.05). Three hours following CLI, the control and vagotomy with TNC groups had significantly more splenic contraction, fewer circulating leukocytes and higher plasma IL-1β, IL-10 and TNF-α levels than TNC rats (p < 0.05). TNC prolonged survival duration after CLI by a median of four hours vs. control (p < 0.05), but no benefit was seen if vagotomy preceded TNC. Peritoneal washout alone increased survival by 3 h (9.2 (7.8–10.5) h). Survival duration increased dramatically with TNC preceding washout, to a 56% survival rate (>10 days). TNC significantly prolonged the survival of rats with severe intraabdominal sepsis by inhibiting systemic proinflammatory responses by activating vagal anti-inflammatory pathways.


2021 ◽  
Author(s):  
Lucas Degrugillier ◽  
Katharina M Prautsch ◽  
Dirk J Schaefer ◽  
Raphael Guzman ◽  
Stefan Schären ◽  
...  

Aim: To develop a consistent model to standardize research in the field of chronic peripheral nerve neuropathy. Methods: The left sciatic nerve of 8-week-old Sprague–Dawley rats was compressed using a customized instrument leaving a defined post injury nerve lumen (400 μm, 250 μm, 100 μm, 0 μm) for 6 weeks. Sensory and motor outcomes were measured weekly, and histomorphology and electrophysiology after 6 weeks. Results: The findings demonstrated compression depth-dependent sensory and motor pathologies. Quantitative measurements revealed a significant myelin degeneration, axon irregularities and muscle atrophy. At the functional level, we highlighted the dynamics of the different injury profiles. Conclusion: Our novel model of chronic peripheral nerve compression is a useful tool for research on pathophysiology and new therapeutic approaches.


Author(s):  
MANOBHARATHI VENGAIMARAN ◽  
KALAIYARASI DHAMODHARAN ◽  
MIRUNALINI SANKARAN

Objective: The central motive of this study is to explore the therapeutic impact of Diosgenin encapsulated Chitosan nanoparticles (DG@CS-NP) on mammary carcinogenesis in female Sprague Dawley rats via modulating hormonal status, cell proliferation, inflammatory responses, and Apoptosis. Methods: 7,12-dimethylbenz(a)anthracene (DMBA) was administered subcutaneously near the mammary gland (25 mg/kg b. wt) to provoke mammary tumor in female Sprague Dawley rats. Following the progress of a tumor, DMBA-induced tumor-bearing rats were medicated orally with 5 mg/kg b. wt of DG@CS-NP. Consequently, the expression of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, Bcl-2, Caspases-3, and p53 in experimental rats were revealed via architectural immunohistochemistry. Further, Diosgenin interactions with these proteins were evidently confirmed by molecular docking analysis. Results: As a result, we noticed diminished levels of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, and Bcl-2 expressions in DG@CS-NP medicated rats as well as with elevated levels of Caspases-3 and p53 expressions. In DMBA rats, the expressions were vice versa. Additionally, molecular docking analyses support these outcomes by highlighting the strong interaction between Diosgenin and breast cancer targets. Conclusion: These reports prove that DG@CS-NP imposes its therapeutic impact by hormonal adjustments, downregulating proteins involved in inflammation and cellular proliferation, and thereby promotes apoptosis by impeding apoptotic inhibitors.


2012 ◽  
Vol 302 (1) ◽  
pp. G145-G152 ◽  
Author(s):  
Vairappan Balasubramaniyan ◽  
Gavin Wright ◽  
Vikram Sharma ◽  
Nathan A. Davies ◽  
Yalda Sharifi ◽  
...  

Ammonia is central in the pathogenesis of hepatic encephalopathy, which is associated with dysfunction of the nitric oxide (NO) signaling pathway. Ornithine phenylacetate (OP) reduces hyperammonemia and brain water in cirrhotic animals. This study aimed to determine whether endothelial NO synthase activity is altered in the brain of cirrhotic animals, whether this is associated with changes in the endogenous inhibitor, asymmetric-dimethylarginine (ADMA) and its regulating enzyme, dimethylarginine-dimethylaminohydrolase (DDAH-1), and whether these abnormalities are restored by ammonia reduction using OP. Sprague-Dawley rats were studied 4-wk after bile duct ligation (BDL) ( n = 16) or sham operation ( n = 8) and treated with placebo or OP (0.6 g/kg). Arterial ammonia, brain water, TNF-α, plasma, and brain ADMA were measured using standard techniques. NOS activity was measured radiometrically, and protein expression for NOS enzymes, ADMA, DDAH-1, 4-hydroxynonenol (4HNE), and NADPH oxidase (NOX)-1 were measured by Western blotting. BDL significantly increased arterial ammonia ( P < 0.0001), brain water ( P < 0.05), and brain TNF-α ( P < 0.01). These were reduced significantly by OP treatment. The estimated eNOS component of constitutive NOS activity was significantly lower ( P < 0.05) in BDL rat, and this was significantly attenuated in OP-treated animals. Brain ADMA levels were significantly higher and brain DDAH-1 significantly lower in BDL compared with sham ( P < 0.01) and restored toward normal following treatment with OP. Brain 4HNE and NOX-1 protein expression were significantly increased in BDL rat brain, which were significantly decreased following OP administration. We show a marked abnormality of NO regulation in cirrhotic rat brains, which can be restored by reduction in ammonia concentration using OP.


2017 ◽  
Vol 1 (S1) ◽  
pp. 60-60
Author(s):  
Andrea Lee Frump ◽  
Margie Albrecht ◽  
Sandra Breuils-Bonnet ◽  
Bakhtiyor Yakubov ◽  
Mary Beth Brown ◽  
...  

OBJECTIVES/SPECIFIC AIMS: Women with pulmonary arterial hypertension (PAH) exhibit superior right ventricular (RV) function and survival compared with men, a phenomenon attributed to poorly understood cardioprotective effects of 17β-estradiol (E2). We hypothesize that E2, through ERα, attenuates PH-induced RV dysfunction by upregulating the pro-contractile and pro-angiogenic peptide apelin. This ERα-mediated increase in apelin is mediated by the myocardial remodeling effector bone morphogenetic protein receptor 2 (BMPR2). METHODS/STUDY POPULATION: ERα, BMPR2, and apelin were measured (western blot) in RVs from patients with PAH-induced RV failure and in RV homogenates from male or female Sprague-Dawley rats with sugen/hypoxia (SuHx) or monocrotaline (MCT)-induced PH. H9c2 rat cardiomyoblasts and cardiac endothelial cells were stressed with TNF-α (10 ng/mL) or staurosporine (50 nM)±E2 (100 nM; 24 h). ERα-, BMPR2-, and apelin-dependence were evaluated by siRNA (5 pM). Downstream apelin target and pro-survival factor ERK1/2 expression was measured (western blot). p<0.05 by ANOVA was considered significant. RESULTS/ANTICIPATED RESULTS: ERα correlated positively with BMPR2 and apelin expression in SuHx-RVs and human RVs. Treatment of SuHx-PH rats with E2 or ERα agonist increased RV BMPR2 and apelin, whereas RV apelin was decreased in E2-treated hypoxic ERα knockout mice (p<0.05), but not in ERβ knockout mice. In H9c2 cells, E2 or ERα agonist attenuated TNF-α- or staurosporine-induced decreases in BMPR2, apelin, and phospho-ERK1/2 (p<0.05 for all endpoints). E2 protection was lost in presence of siRNA directed against ERα, BMPR2, or apelin (p<0.05). ERα was necessary for E2-mediated increases in BMPR2, apelin, and ERK1/2, and BMPR2 was required for the E2-mediated increase in apelin (p<0.05 for siRNA vs. scramble). ERα, BMPR2, and apelin protein was increased in decompensated human RVs but downstream phospho-ERK signaling was disrupted. DISCUSSION/SIGNIFICANCE OF IMPACT: E2, via ERα, increases BMPR2 and apelin in the failing RV and in stressed rat cardiomyoblasts. The E2-mediated increase in apelin is BMPR2-dependent and likely occurs through direct binding of ERα to the BMPR2 promoter. Harnessing this E2-ERα-BMPR2-apelin axis during RV compensation may lead to novel, RV-targeted therapies for PAH patients of either sex.


2003 ◽  
Vol 284 (4) ◽  
pp. R916-R927 ◽  
Author(s):  
Zhi-Hua Zhang ◽  
Shun-Guang Wei ◽  
Joseph Francis ◽  
Robert B. Felder

In pathophysiological conditions, increased blood-borne TNF-α induces a broad range of biological effects, including activation of the hypothalamic-pituitary-adrenal axis and sympathetic drive. In urethane-anesthetized adult Sprague-Dawley rats, we examined the mechanisms by which blood-borne TNF-α activates neurons in paraventricular nucleus (PVN) of hypothalamus and rostral ventrolateral medulla (RVLM), two critical brain regions regulating sympathetic drive in normal and pathophysiological conditions. TNF-α (0.5 μg/kg), administered intravenously or into ipsilateral carotid artery (ICA), activated PVN and RLVM neurons and increased sympathetic nerve activity, arterial pressure, and heart rate. Responses to intravenous TNF-α were not affected by vagotomy but were reduced by mid-collicular decerebration. Responses to ICA TNF-α were substantially reduced by injection of the cyclooxygenase inhibitor ketorolac (150 μg) into lateral ventricle. Injection of PGE2 (50 ng) into lateral ventricle or directly into PVN increased PVN or RVLM activity, respectively, and sympathetic drive, with shorter onset latency than blood-borne TNF-α. These findings suggest that blood-borne cytokines stimulate cardiovascular and renal sympathetic responses via a prostaglandin-dependent mechanism operating at the hypothalamic level.


1994 ◽  
Vol 79 (1) ◽  
pp. 211-215 ◽  
Author(s):  
William F. Vitulli ◽  
Rwanda Aker ◽  
Stanley W. Howard ◽  
Wendy M. Jones ◽  
Morgan W. Kimball ◽  
...  

Salt (sodium chloride) has been linked to increased blood pressure and a rise in core body temperature. The objective of this study was to investigate the role played by salt in altering behavioral thermoregulation in albino rats. Different doses of sodium chloride were administered (ip) prior to fixed-interval 2-min. schedules of microwave reinforcement in rats tested in a cold Skinner Box. Three Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of MW reinforcement in a repeated-measures reversal design. Friedman's non-parametric test showed significant differences among sodium chloride doses and physiologically normal saline. Post hoc sign tests showed that all doses of NaCI suppressed operant behavior for heat except 60 mg/kg. The hypothesis that sodium chloride lowers hypothalamic set point for heat was partially supported.


Pharmacology ◽  
2019 ◽  
Vol 104 (1-2) ◽  
pp. 71-80 ◽  
Author(s):  
Ying Zhang ◽  
Shaoyu Ren ◽  
Ying Ji ◽  
Yafeng Liang

Background: Our study investigated the therapeutic role and potential mechanisms of pterostilbene (PS) in diabetic nephropathy (DN) rats. Methods: DN models were established by high-fat diet after streptozotocin injection. A total of 50 Sprague-Dawley rats were randomly divided into control, DN, PS-treated groups (PS-H, PS-M, PS-L). PS was administered to rats by gavage for 8 weeks at 3 different doses (25, 10, and 5 mg/kg/day). The levels of oxidative stress activity (superoxide dismutase [SOD], malondialdehyde [MDA], glutathione peroxidase [GSH-PX]) and inflammatory factors (tumor necrosis factor [TNF]-α, interleukin (IL)-6, IL-1β, monocyte chemoattractant factor [MCP]-1) were detected by ­ELISA. TGF-β, Smad1, and fibronectin (FN) were measured through immunohistochemistry. The relative expressions of phospho-IκBα/IκBα, phospho-IκB kinases (IKK)β/IKKβ, phospho-nuclear factor-κB (NF-κB) p65/NF-κB p65 were detected by western blot. Results: Compared with DN group, the levels of TNF-α, IL-6, IL-1β, and MCP-1 were decreased in the PS-H group (p < 0.05). Meanwhile, the levels of SOD, MDA, GSH-PX improved in kidney and serum in PS-H groups (p< 0.05). PS also significantly decreased the level of phospho-NF-κB p65 and increased the levels of phospho- IKKβ and phospho-Iκ-Bα (p < 0.05). The results showed that PS treatment decreased TGF-β, Smad1, and FN expressions. Conclusion: PS had potential therapeutic effects on DN, which may be related to the regulation of NF-κB pathway.


2007 ◽  
Vol 172 ◽  
pp. S230-S231
Author(s):  
Yana González ◽  
Ana Bada ◽  
Bárbara González ◽  
Osvaldo Hernández ◽  
Juana Hernández ◽  
...  

2011 ◽  
Vol 301 (1) ◽  
pp. R148-R158 ◽  
Author(s):  
Andrea Vecchiola ◽  
Juan Francisco de la Llera ◽  
Rodrigo Ramírez ◽  
Pablo Olmos ◽  
Cristobal I. Herrera ◽  
...  

Elastase intratracheal instillation induces early emphysema in rodents. However, Syrian Golden hamsters develop more severe emphysema than Sprague-Dawley rats. We have reported species differences in oxidant/antioxidant balance modulating antiprotease function early after instillation. We now hypothesize that other components of the initial lung response to elastase might also be species-dependent. Sprague-Dawley rats and Syrian Golden hamsters received a single dose of pancreatic elastase (0.55 U/100 g body wt) to study acute lung injury biomarkers. Using serum, lung, and bronchoalveolar lavage fluid (BALF) samples, we evaluated changes in alveolar-capillary permeability, alpha 1-antitrypsin (α1-AT) concentration and activity, glutathione content, and proinflammatory cytokines. Rats showed a large increase in alveolar-capillary permeability and few hemorrhagic changes, whereas hamsters exhibited large hemorrhagic changes ( P < 0.01) and mild transendothelial passage of proteins. Western blots showed a 30-fold increase in BALF α1-AT concentration in rats and only a 7-fold increase in hamsters ( P < 0.001), with [α1-AT-elastase] complexes only in rats, suggesting differences in antiprotease function. This was confirmed by the α1-AT bioassay showing 20-fold increase in α1-AT activity in rats and only twofold increase in hamsters ( P < 0.001). In rats, results were preceded by a 3-, 60-, and 20-fold increase in IL-6, IL-1β, and TNF-α respectively ( P < 0.001). In hamsters, only IL-1β and TNF-α showed mild increases. All parameters studied were back to baseline by 4 days. In conclusion, several components of the initial lung response showed species differences. Cytokine release pattern and functional inhibition of α1-AT were the most significant components differing among species and could account for differences in susceptibility to elastase.


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