Damage In Rat Model Research Articles

Optimization, physical-chemical evaluation and healing activity of chitosan ointment

Context: Chitosan has received attention as a functional, sustainably renewable, nontoxic and biodegradable biopolymer for pharmaceutical applications such as healing agent. Aims: To design a semisolid pharmaceutical form (ointment), employing 1% chitosan as an active pharmaceutical ingredient. Methods: The formulation was carried out through D-optimal mixing design, with a linear model. Variation components evaluated were the concentration of sodium hydroxide, water and anhydrous lanolin. Variables included those of response pH and extensibility. Three batches were produced, and the physical and chemical stability of the ointment was assessed through stress and shelf-life tests for 24 months. Physical-chemical parameters studied included organoleptic characteristics, chitosan content, rheological behavior, apparent viscosity, pH and extensibility. Wound healing activity was also tested for burns damage model in rats. Results: The mixture design showed that the best formulation was the one containing 0.12% sodium hydroxide, 20.0% anhydrous lanolin and 40.0% water, with the mechanical-structural behavior characteristics of a semisolid product. This product had healing effects and showed adequate physical chemical stability during the time under study. Conclusions: The results of this study suggest that 1% chitosan ointment design favors scarring in the second-degree burn damage model in rats skin applied for 14 days at the rate of daily administration.

Hepatoprotective activity of royal jelly on mercuric chloride–induced damage model in rats

Background: Mercuric chloride (MC) is the chemical composition of mercury and chlorine with many side effects such as oxidative stress referring to mercury toxicity. Royal jelly (RJ) as a honey bee secretion has antioxidant activities. This study was designed to evaluate the effects of RJ against the parameters of hepatic damage in male rats induced by MC toxicity. Materials and Methods: In this study, 48 male rats were randomly assigned into six groups: sham (saline) and MC control (50 mg/kg) groups; RJ groups (200 mg/kg RJ for 1 day and 200 mg/kg RJ for 7 days, orally) and MC + RJ groups (200 mg/kg RJ orally + 50 mg/kg MC intraperitoneally for 1 day, and 200 mg/kg RJ orally and 50 mg/kg MC intraperitoneally for 7 days). Griess technique was used for the determination of serum nitric oxide (NO) level. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) concentrations were determined for liver functional disturbances value. In addition, thiobarbituric acid reactive species, antioxidant capacity, the diameter of hepatocytes, and the central hepatic vein (CHV) were investigated. Results: MC administration significantly increased the liver malondialdehyde (MDA) and NO levels, the mean diameter of CHV and hepatocyte, hepatic enzymes, and decreased tissue Ferric reducing antioxidant power (FRAP) level compared to the sham group (P < 0.01). The RJ and RJ + MC in all treatments significantly reduced the mean diameter of hepatocyte and CHV, hepatic enzymes, renal MDA and NO levels, and increased tissue FRAP level compared to the MC control group (P < 0.01). It seems that RJ administration recovers the hepatic injury induced by MC in rats.

Telmisartan regulates the development of cerebral ischemia by alleviating endoplasmic reticulum stress.

Recent studies have shown that telmisartan (TMS) is effective for the protection against ischemia/brain damage in rat models. However, the specific underlying mechanism is poorly understood. In line with previous results, our data showed that TMS improves CBF and physiological variables, including pH, pCO2, pO2. Through CD31 immunofluorescence staining, reduction of blood vessel density was found in MCAO group, but TMS treatment could enhance the cerebral vascular density in the ischemic area. Meanwhile, TMS treatment could enhance the number of BrdU/lectin double-positive cells. Furthermore, the reduction of nestin-positive cells was identified in the brain of MCAO rats, while the number of nestin-positive cells was significantly increased after TMS administration. Furthermore, the expression of ERS-related proteins, including GRP78, CHOP/GADD153, Caspase12 was increased after MCAO, but was decreased after administration of TMS, thereby enhancing angiogenesis and neuron regeneration.

MicroRNA-374 Exerts Protective Effects by Inhibiting SP1 Through Activating the PI3K/Akt Pathway in Rat Models of Myocardial Ischemia-Reperfusion After Sevoflurane Preconditioning

Ischemic heart disease is a leading cause of death in cardiovascular diseases, and microRNAs (miRs) have been reported to be potential therapeutic targets in heart disease. Herein, this study aims to investigate the effects of microRNA (miR)-374 on myocardial ischemia-reperfusion (I/R) injury in rat models pretreated with sevoflurane by targeting SP1 through the PI3K/Akt pathway. SD rats were grouped into sham, I/R and sevoflurane + I/R (sevoflurane preconditioning and I/R) groups. The biochemical indicators, pathological changes, positive expression of SP1 protein, and apoptosis rates were measured using biochemical detection, Evans blue-TTC staining, immunohistochemistry and TUNEL staining. RT-qPCR and Western blotting were used to investigate the expression of miR-374 mRNA and the protein expression of SP1, PI3K, HO-1, p53, iNOS, c-fos, Akt/p-Akt, and GSK-3β/p-GSK-3β. Cardiomyocytes were treated with miR-374 mimics, miR-374 inhibitors, or siRNA-SP1. Cardiomyocyte proliferation and cycle distribution and apoptosis were studied by MTT and flow cytometry. Compared with the I/R group, in the sevoflurane + I/R group, serum SOD and IL-10 increased, while MDA, LDH, CK, TNF-α, IL-6 and IL-10 decreased, as did the percentage of infarct area, the positive rate of SP1 and the apoptosis index. The expression of SP1, p53, iNOS and c-fos decreased, and the miR-374 expression of PI3K, HO-1, Akt/p-Akt, GSK-3β/p-GSK-3β increased. With the upregulation of miR-374 and the downregulation of SP1, the expression of SP1, p53, iNOS and c-fos decreased, as did the proportion of cells in G1 phase and the apoptosis rate; the expression of PI3K, HO-1, Akt/p-Akt, GSK-3β/p-GSK-3β increased. The results in the miR-374 inhibitor group contrasted with the above results. The results indicated that miR-374 could alleviate myocardial I/R damage in rat models pretreated with sevoflurane by targeting SP1 by activating the PI3K/Akt pathway.

Behavioral outcomes of a novel, pelvic nerve damage rat model of fecal incontinence.

Fecal incontinence (FI) has a multifactorial pathophysiology with a severe social impact. The most common cause for FI is pudendal nerve damage, which mostly occurs in women during or after labor. A better understanding of the pathophysiology is required to optimize treatment of FI. In this study, we evaluate the use of a novel pelvic nerve damage rat model of FI. This new model simulates the forces on the pelvic floor during labor by prolonged transvaginal, retro-uterine intrapelvic balloon distention in female rats. Number of fecal pellets produced per day and defecation pattern was compared between the experimental and control group for 2weeks. The cages of the rats were divided in food, nesting and latrine areas to evaluate changes in defecation pattern. The FI Index (FII) was calculated to assess the ratio of fecal pellets between the non-latrine areas and the total number of pellets. A higher score represents more random distribution of feces outside the latrine area. Total number of fecal pellets was higher in the experimental group as compared with the controls. In both groups most fecal pellets were deposited in the nesting area, which is closest to the food area. The experimental group deposited more fecal pellets in the latrine area and had a lower FII indicating less random distribution of feces outside the latrine area. Transvaginal, retro-uterine intrapelvic balloon distention is a safe and feasible animal model simulating the human physiologic impact of labor by downwards pressure on the pelvic floor.

Silencing of SOCS-1 and SOCS-3 suppresses renal interstitial fibrosis by alleviating renal tubular damage in a rat model of hydronephrosis.

Our study was performed to elucidate how SOCS-1/3 silencing suppresses renal interstitial fibrosis (RIF) by alleviating renal tubular damage in rat models affected by hydronephrosis. Male Wistar rats were randomly selected to establish hydronephrosis rat model, after which all rats were classified into normal, model, negative control (NC), siRNA-SOCS-1, siRNA-SOCS-3, and siRNA-SOCS-1 + siRNA-SOCS-3 groups. The levels of urine protein, serum creatinine (Scr), and blood urea nitrogen (BUN) were detected. ELISA was performed to determine levels of cystatin (CysC), β2-microglobulin (β2-MG), interleukin (IL)-6, and tumor necrosis factor (TNF)-α. RT-qPCR and Western blotting were used for mRNA and protein expressions of SOCS-1, SOCS-3, α-smooth muscle actin (α-SMA), and transforming Growth Factor (TGF)-β1. Compared with the normal group, the levels of Scr, BUN, urine protein, NAG, CysC, β2-MG, IL-6, and TNF-α were increased in other groups, as well as elevated mRNA and protein expressions of SOCS-1, SOCS-3, α-SMA, and TGF-β1. The siRNA-SOCS-1, siRNA-SOCS-3, and siRNA-SOCS-1 + siRNA-SOCS-3 groups were found with decreased levels of Scr, BUN, urine protein, NAG, CysC, β2-MG, IL-6, and TNF-α, as well as mRNA and protein expressions of SOCS-1, SOCS-3, α-SMA, and TGF-β1, including positive rates of SOCS-1 and SOCS-3 proteins in comparison with the model and NC groups. In comparison with the siRNA-SOCS-1 and siRNA-SOCS-3 groups, the siRNA-SOCS-1 + siRNA-SOCS-3 group exhibited decreased levels of Scr, BUN, urine protein, NAG, CysC, β2-MG, IL-6, and TNF-α. Our study demonstrated that silencing of SOCS-1/3 may suppress RIF by alleviating the renal tubular damage in rat models affected by hydronephrosis.

Hydroalcoholic extract of Dorema aucheri leaves prevents weakening of the brain antioxidant defense system and inhibits oxidative damage in rat model of ischemic stroke

Hydroalcoholic extract of Dorema aucheri leaves prevents weakening of the brain antioxidant defense system and inhibits oxidative damage in rat model of ischemic stroke

Intra-articular Recombinant Human Proteoglycan 4 Mitigates Cartilage Damage After Destabilization of the Medial Meniscus in the Yucatan Minipig

Background: Lubricin, or proteoglycan 4 (PRG4), is a glycoprotein responsible for joint boundary lubrication. PRG4 has been shown previously to be down-regulated after traumatic joint injury such as a meniscal tear. Preliminary evidence suggests that intra-articular injection of PRG4 after injury will reduce cartilage damage in rat models of surgically induced posttraumatic osteoarthritis. Objective: To determine the efficacy of intra-articular injection of full-length recombinant human lubricin (rhPRG4) for reducing cartilage damage after medial meniscal destabilization (DMM) in a preclinical large animal model. Study Design: Controlled laboratory study. Methods: Unilateral DMM was performed in 29 Yucatan minipigs. One week after DMM, animals received 3 weekly intra-articular injections (3 mL per injection): (1) rhPRG4 (1.3 mg/mL; n = 10); (2) rhPRG4+hyaluronan (1.3 mg/mL rhPRG4 and 3 mg/mL hyaluronan [~950 kDA]; n = 10); and (3) phosphate-buffered saline (PBS; n = 9). Hindlimbs were harvested 26 weeks after surgery. Cartilage integrity was evaluated by use of macroscopic (India ink) and microscopic (safranin O–fast green and hematoxylin and eosin) scoring systems. Secondary outcomes evaluated via enzyme-linked immunosorbent assay (ELISA) included PRG4 levels in synovial fluid, carboxy-terminal telepeptide of type II collagen (CTX-II) concentrations in urine and serum, and interleukin 1β (IL-1β) levels in synovial fluid and serum. Results: The rhPRG4 group had significantly less macroscopic cartilage damage in the medial tibial plateau compared with the PBS group (P = .002). No difference was found between the rhPRG4+hyaluronan and PBS groups (P = .23). However, no differences in microscopic damage scores were observed between the 3 groups (P = .70). PRG4 production was elevated in the rhPRG4 group synovial fluid compared with the PBS group (P = .033). The rhPRG4 group presented significantly lower urinary CTX-II levels, but not serum levels, when compared with the PBS (P = .013) and rhPRG4+hyaluronan (P = .011) groups. In serum and synovial fluid, both rhPRG4 (P = .006; P = .017) and rhPRG4+hyaluronan groups (P = .009; P = .03) presented decreased IL-1β levels. Conclusion: All groups exhibited significant cartilage degeneration after DMM surgery. However, animals treated with rhPRG4 had the least amount of cartilage damage and less inflammation, providing evidence that intra-articular injections of rhPRG4 may slow the progression of posttraumatic osteoarthritis. Clinical Relevance: Patients with meniscal trauma are at high risk for posttraumatic osteoarthritis. This study demonstrates that an intra-articular injection regimen of rhPRG4 may attenuate cartilage damage after meniscal injury.

Reversal of Experimental Liver Damage after Transplantation of Stem-Derived Cells Detected by FTIR Spectroscopy.

The transplantation of autologous BM-MSCs holds great potential for treating end-stage liver diseases. The aim of this study was to compare the efficiency of transplanted rBM-MSCs and rBM-MSC-derived differentiated stem cells (rBM-MSC-DSCs) for suppression of dimethylnitrosamine-injured liver damage in rat model. Synchrotron radiation Fourier-transform infrared (SR-FTIR) microspectroscopy was applied to investigate changes in the macromolecular composition. Transplantation of rBM-MSC-DSCs into liver-injured rats restored their serum albumin level and significantly suppressed transaminase activity as well as the morphological manifestations of liver disease. The regenerative effects of rBM-MSC-DSCs were corroborated unequivocally by the phenotypic difference analysis between liver tissues revealed by infrared spectroscopy. Spectroscopic changes in the spectral region from 1190–970 cm−1 (bands with absorbance maxima at 1150 cm−1, 1081 cm−1, and 1026 cm−1) indicated decreased levels of carbohydrates, in rBM-MSC-DSC-transplanted livers, compared with untreated and rBM-MSC--transplanted animals. Principal component analysis (PCA) of spectra acquired from liver tissue could readily discriminate rBM-MSC-DSC-transplanted animals from the untreated and rBM-MSC-transplanted animals. We conclude that the transplantation of rBM-MSC-DSCs effectively treats liver disease in rats and SR-FTIR microspectroscopy provides important insights into the fundamental biochemical alterations induced by the stem-derived cell transplantation, including an objective “signature” of the regenerative effects of stem cell therapy upon liver injury.

MITOCHONDRIAL DYSFUNCTION PLAYS A ROLE IN IMPAIRED NEURONAL DIFFERENTIATION IN SCHIZOPHRENIA

Schizophrenia (SZ) is conceptualized as a neurodevelopmental disorder, involving dysfunction of dopaminergic and glutamatergic systems as well as of mitochondria. Among the major obstacles in studying pathological processes in SZ are the inaccessibility of the brain and inability to study brain processes prior to the onset of this disorder. Animal models of the disease can shed light on possible developmental aberration in the disease. An additional attractive experimental tool to study neurodevelopmental impairments together with mitochondrial dysfunction in SZ, is differentiation of induced pluripotent stem cells (iPSC) into neurons.iPSC from SZ patients and healthy controls were reprogrammed from hair follicle keratinocytes and differentiated into dopaminergic and glutamatergic neurons. Mitochondria were assessed by analyzing mitochondrial membrane potential, network dynamics and apoptosis markers. The effect of transferring isolated active normal mitochondria (IAN-MIT) into SZ- iPSCs was studied. Furthermore, mitochondrial complex I subunits expression was followed in brains of neonatal ventral hippocampal (nVH) damage rat model of SZ.SZ-derived dopaminergic cells showed severely impaired ability to differentiate, whereas glutamatergic cells were unable to maturate. Mitochondrial complex I driven respiration was impaired in SZ-derived keratinocytes and iPSC along with perturbations in mitochondrial membrane potential and in mitochondrial network in neurons. However, amending mitochondrial function by IAN-MIT transfer improved differentiation of SZ-iPSC derived glutamatergic neurons. In prefrontal cortex, but not the cingulate cortex, of nVH damage rat model of SZ we observed a significant prepubertal increase and postpubertal decrease in mitochondrial complex I subunits. No such change was observed in neonatal exposure to hypoxia rat model.Our study shows perturbations in neural differentiation and mitochondrial function, which are interconnected and of relevance to early neurodevelopmental processes in SZ.

Evaluation of skin irritation in rats using simultaneous laser Doppler flowmetry and oxygenation monitoring

The possibility of assessment of skin irritation in rats with the use of simultaneous laser Doppler flowmetry (LDF) and oxygenation monitoring was investigated. The study was designed according to ISO 10993-10 using formaldehyde as a model irritant. 4-Hour application of 1 % formaldehyde induced significant local increase in skin microcirculation for the first 2 days by a factor of up to 2.4, whereas tissue oxygenation increased in much lower extent. The microcirculation was significantly inhibited by 10 % formaldehyde following treatment and then it gradually increased for 24 and 48 h of recovery period. The results correlated with visual evaluation of skin edema and erythema in treated zones. LDF/oxygenation signals provide early information on skin irritation and damage in rat model. The technique is valuable for preclinical/toxicological studies of chemical substances and medical materials.

Protective effect of treatment with thiamine or benfotiamine on liver oxidative damage in rat model of acute ethanol intoxication

AimsThe aim of this study was to evaluate possible beneficial effects of treatment with thiamine or benfotiamine in an animal model of acute ethanol intoxication. Main methodsThirty male Wistar rats were separated at random into three groups of 10 animals each: Ethanol (E), Ethanol treated with thiamine (T) and Ethanol treated with benfotiamine (BE). Rats were gavaged with single dose of ethanol (5g/kg, 40% v:v). After 30min of ethanol gavage the animals were treated with thiamine or benfotiamine. Six hours after first gavage, the animals were euthanized and blood and liver samples were collected for ethanol and oxidative stress biomarkers quantification. Key findingsSerum ethanol levels were higher in animals treated with thiamine or benfotiamine while hepatic alcohol levels were higher in animals of the group treated with benfotiamine comparing to controls or thiamine treated groups. The lipid peroxidation biomarkers were diminished for the groups treated with thiamine or benfotiamine comparing to E animals. Concerning protein oxidative damage parameters, they were enhanced for animals treated with benfotiamine in relation to other groups. SignificanceIn conclusion, the treatment with thiamine or benfotiamine even 30min after the massive dose of ethanol has proven to be beneficial against liver damage. Improved results were obtained with benfotiamine in relation to oxidative damage from aqueous compartments.

Protective Effect of Epigallocatechin-3-Gallate (EGCG) the Major Tea Polyphenolic, Against Intracerebroventricularly Colchicine Induced Oxidative Damage Production in Brain and Cognitive Dysfunction in Mice

Alzheimer’s disease is a neuro degeneration which generates memory impairment in human. Administration of colchicine centrally in brain is well known to generate cognitive impairment and memory dysfunction in central nervous system which produces Alzheimer’s disease. In this present experimental study, evaluation of the therapeutic effects of EGCG against the colchicine generated cognitive impairment and oxidative dysfunction in Alzheimer’s disease induced rat model is executed. Colchicine was given intra-cerebroventricularly which results a memory loss in Morris water maze and produced marked oxidative stress induced damage. It also caused a profound increment in acetyl cholinesterase enzyme inhibitory activity. Treatment with EGCG was given every day orally for a course of 25 days prior to colchicine application in rat model. Treatment with EGCG caused significant improvement in the cognitive function and reduced oxidative damage in rat model. This study demonstrates the therapeutic effect of EGCG against colchicine produced cognitive and oxidative injury generated in Alzheimer’s disease model.

Emulsified Isoflurane Produces Cardioprotection against Severe Burn-Induced Cardiac Shock

Background: Cardiac shock, occurring at the early stage of severe burns, causes cardiac insufficiency. Cardiac dysfunction after severe burn is associated with myocardial injury. Emulsified isoflurane (EIso) has been demonstrated to have cardioprotective effect against ischemia and reperfusion injury. Whether burn-induced cardiac dysfunction is influenced by EIso is currently unknown. We tested the hypothesis that EIso decreases myocardial damage in rat model with severe burn.Methods: In an in vivo study, sprague dawley rats, weighting 250-300 g, were randomized into four groups: 1) sham-burn group (sham, saline), 2) burn group (CON, saline, 30% total body surface area [TBSA] full-thickness burn), 3) burn+30% intralipid (IL, vehicle for EIso) group, and 4) burn+8% EIso of 1.5 ml/kg (EIso) group. Lactated ringers solution was immediately injected intraperitoneally to all rats after burn injury according to Parkland formula (4.0 ml/kg/1%TBSA), followed by continuous intravenous infusion of isovolumetric saline, intralipid and EIso for 30 minutes in each group. Hemodynamic parameters were constantly monitored throughout the experiment. 3 hours post-burn, hearts were excised for determination of enzyme activity and apoptosis.Results: Under baseline conditions, no significant differences in systemic hemodynamics were observed among the groups. Heart rate decreased after burn injury in the CON, EIso and IL groups. Compared with the sham group, burn injury was accompanied by a reduction of systolic function in left ventricular systolic pressure (LVSP) and maximum rate of increase in left ventricular pressure (dP/dtmax), and an increase in maximum rate of decrease in left ventricular pressure (-dP/dtmax). 2 to 3 hours after burn, EIso attenuated decreases in LVSP and dP/dtmax. Malondialdehyde (MDA) was reduced from 2.55±0.29 mmol/mg prot in CON group and 2.21±0.23 in IL group to 1.79±0.28 in EIso group (P<0.01 vs. CON and P<0.05 vs. IL). EIso also increased the level of superoxide dismutase (SOD) (162.5±10.5 U/mg prot), compared with CON group (140.4 ±12.1, P<0.01). However, there was no difference regarding the changes of apoptotic protein (Bcl-2 and Bax) expression among groups. Meanwhile, no apoptotic cells were detected throughout the experiment in any groups.Conclusions: EIso could protect hearts against severe burns during the early stage post-burn, which may be independent from the involvement of apoptosis. Citation: Zhao-Yang Hu, Ya-Dong Fang, Ze-Gang Yin, Bai-Xing Li, Yue-Sheng Huang, Jin Liu. Emulsified isoflurane produces cardioprotection against severe burn-induced cardiac shock. J Anesth Perioper Med 2016; 3: 11-17. doi: 10.24015/JAPM.2016.0002This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Bakkenolide-IIIa Protects Against Cerebral Damage Via Inhibiting NF-κB Activation.

This study was designed to examine the neuroprotective effects of bakkenolide-IIIa, a major novel compound extracted from the rhizome of P. trichinous. Transient focal cerebral damage model in rats and oxygen-glucose deprivation (OGD) in cultured hippocampal neurons were performed. The amount of apoptotic neurons was determined using TUNEL assay. The expressions of Bcl-2, Bax, Akt, ERK1/2, IKKβ, IκBα were measured using Western blot. The nuclear translocation and activation of NF-κB was measured using a fluorescence microscope and electrophoretic mobility shift assay (EMSA). Bakkenolide-IIIa (4, 8, 16 mg/kg; i.g.) was administered immediately after reperfusion could reduce the brain infarct volume, and the neurological deficit, as well as a high dose of bakkenolide-IIIa, increases the 72 h survival rate in cerebrally damaged rats. In vitro data demonstrated that bakkenolide-IIIa could increase cell viability and decrease the amount of apoptotic cells in cultured primary hippocampal neurons exposed to OGD. Bakkenolide-IIIa also dose-dependently increased the ratio of Bcl-2 to Bax. These results indicated that inhibition of apoptosis partly mediated the neuroprotection of bakkenolide-IIIa. Furthermore, bakkenolide-IIIa inhibited the phosphorylation of Akt, ERK1/2, IKKβ, IκBα, and p65 in cultured hippocampal neurons exposed to OGD. Bakkenolide-IIIa not only inhibited the nuclear translocation of NF-κB in cultured neurons exposed to OGD, but also inhibited the activation of NF-κB in peri-infarct area in cerebrally damaged rats. Collectively, our findings indicated that bakkenolide-IIIa protects against cerebral damage by inhibiting AKT and ERK1/2 activation and inactivated NF-κB signaling.

Preclinical evaluation of injectable reduced hydroxocobalamin as an antidote to acute carbon monoxide poisoning

Current management of acute inhalational carbon monoxide (CO) toxicity includes hyperbaric or normobaric O2 therapy. However, efficacy has not been established. The purpose of this study was to establish therapeutic proof of concept for a novel injectable antidote consisting of the combination of hydroxocobalamin and ascorbic acid into a reduced form (B12r) as demonstrated by clinically significant increase (>500 ppm) in CO2 production, reduced carboxyhemoglobin (COHgb) half-life (COHgb t1/2), and increased cerebral O2 delivery and attenuation of CO-induced microglial damage in a preclinical rodent model of CO toxicity. B12r-mediated conversion of CO to CO2 and COHgb t1/2 in human blood were measured by gas analysis and Raman resonance spectroscopy. Rats were exposed to either air or CO and then injected with saline or B12r. Cognitive assessment was tested in a Morris water maze. Brain oxygenation was measured with Licox. Brain histology was assessed by fluorescent antibody markers and cell counts. B12r resulted in significant CO2 production (1,170 ppm), compared with controls. COHgb t1/2 was reduced from 33 minutes (normal saline) to 17.5 (p < 0.001). In rat models, severe CO-induced brain hypoxia (PbtO2, 18 mm Hg) was followed by significant reduction in τ25 to 12 minutes for B12r rats versus 40 minutes for normal saline-treated rats (p < 0.0001). There was major attenuation of CO-induced microglial damage, although cognitive performance differences were minimal. Our preclinical data suggest that the novel synergism of hydroxocobalamin with ascorbic acid has the potential to extract CO through conversion to CO2, independently of high-flow or high-pressure O2. This resulted in a clinically significant off-gassing of CO2 at levels five to eight times greater than those of controls, a clinically significant reduction in COHgb half-life, and evidence of increased brain oxygenation and amelioration of myoglial damage in rat models. Reduced hydroxocobalamin has major potential as an injectable antidote for CO toxicity.

Changes in glucose transporter expression and nitric oxide production are associated with liver injury in diabetes.

In diabetes mellitus (DM), both hyperglycaemia and hyperlipidaemia can initiate accumulation of fat in the liver, which might be further mediated by inducible nitric oxide synthase. We have studied changes in GLUT1, nitric oxide (NO(·)) concentration and liver damage in two rat DM models. STZ model was induced by strepozotocin 50 mg/kg. HS model was induced by high-fat diet and 30 mg/kg streptozotocin. GLUT1 expression was studied by means of real-time RT-PCR and immunohistochemistry. Production of NO(·) was monitored by means of erythrocyte sedimentation rate spectroscopy of Fe-DETC-NO complex. Liver damage was assessed using histological activity index (HAI). NO(·) concentration was increased in the liver of STZ rats, but it did not change in HS rats (control 36.8 ± 10.3; STZ 142.1 ± 31.1; HS 35.4 ± 9.8 ng/g). Liver HAI was higher in STZ group, 8.6 ± 0.17 versus HS 4.7 ± 0.31, p < 0.05. GLUT1 protein expression was elevated only in STZ group, 16 ± 3 cells/mm(2) versus Control 5 ± 2 cells/mm(2), p = 0.007. Hyperglycaemia sooner causes severe liver damage in rat models of DM, compared with hyperlipidaemia, and is associated with increased NO(·) production. GLUT1 transporter expression might be involved in toxic effects of glucose in the liver. We have obtained novel data about association of GLUT1 expression and NO(·) metabolism in the pathogenesis of liver injury in DM. Increased GLUT1 expression was observed together with overproduction of NO(·) and pronounced liver injury in severely hyperglycaemic rats. On the contrary, moderately hyperglycaemic hyperlipidaemic rats developed only moderate liver steatosis and no increase in GLUT1 and NO(·). GLUT1 overexpression might be implicated in the toxic effects of glucose in the liver. Glycotoxicity is associated with oxidative stress and NO(·) hyperproduction. GLUT1 and NO(·) metabolism might become novel therapeutic targets in liver steatosis.

Urinary phosphorus excretion per creatinine clearance as a prognostic marker for progression of chronic kidney disease: a retrospective cohort study.

BackgroundWhether phosphate itself has nephrotoxicity in patients with chronic kidney disease (CKD) is controversial, although phosphate excretion into urine may cause tubular damage in rat models. To evaluate actual phosphate load on each nephron, we examined the association between 24-h urinary phosphorus excretion per creatinine clearance (24-h U-P/CCr), a newly proposed index that is a surrogate for nephron load, and CKD progression in patients with CKD.MethodsWe conducted a single-center, retrospective cohort study. To avoid potential confounders for protein intake, only patients on our educational program for CKD with a fixed diet regimen and aged 20 years or older were included. The observation period was 3 years. Primary outcomes were CKD progression defined as a composite of end-stage kidney disease (ESKD) or 50 % reduction of estimated glomerular filtration rate. Patients were stratified by quartiles of 24-h U-P/CCr levels as Quartiles 1–4. The association was examined in three models: unadjusted (Model 1), adjusted for risk factors for CKD progression (Model 2), and factors that affect renal phosphate handling (Model 3).ResultsA total of 191 patients met the eligibility criteria. Patients with higher 24-h U-P/CCr showed a higher risk for the composite outcomes. The hazard ratios [95 % confidence interval] for 24-h U-P/CCr levels in Quartile 2, 3, and 4, respectively, versus Quartile 1 were 2.56 (1.15–6.24), 7.53 (3.63–17.62), and 12.17 (5.82–28.64) in Model 1; 1.66 (0.63–4.97), 3.57 (1.25–11.71), and 5.34 (1.41–22.32) in Model 2; and 3.07 (0.97–11.85), 7.52 (2.13–32.69), and 7.89 (1.74–44.33) in Model 3.ConclusionsOur study showed that higher phosphorus excretion per creatinine clearance was associated with CKD progression.

Curcumin Inhibits Apoptosis and Brain Edema Induced by Hypoxia-Hypercapnia Brain Damage in Rat Models

Curcumin, extracted from South Asian spice turmeric, has been determined to have the promising ability in antioxidation and antiinflammation. However, the effect of curcumin on treating brain damage has been not reported. in this article, the aim was to evaluate the effect of curcumin on cell apoptosis in rats exposed to hypoxia-hypercapnia and explore the therapeutic potential of curcumin in hypoxia-hypercapnia brain damage (HHBD). sprague Dawley rats were randomly assigned into 3 groups: control group, hypoxia-hypercapnia group and curcumin group. The Fas/FasL expressions in HHBD rats treated by curcumin were measured by immunohistochemical staining and western blotting. The pathological changes of brain cells were observed by transmission electron microscope. Rats with HHBD showed significant increase of Fas/FasL expression and ultrastructural changes in brain tissue cells. Curcumin intervention effectively reversed the Fas/FasL-mediated apoptosis and HHBD-induced brain edema. Curcumin may be a potential therapeutic alternative for HHBD.

Protective effects of tao-Hong-si-wu decoction on memory impairment and hippocampal damage in animal model of vascular dementia.

Tao-Hong-Si-Wu decoction (TSD) as a traditional chinese medicine (TCM) has been developed to treat thrombotic diseases for hundreds of years, and vascular dementia (VD) is a cognitive dysfunction syndrome caused by cerebral embolism. In this study, the protective effect of TSD on memory impairment and brain damage in rat model of VD induced by middle cerebral artery occlusion (MCAO) was investigated. The study showed that rats in MCAO treatment with TSD for 14 days significantly improved behavioral function, increased densities of neuron, and induced angiogenesis in the brain compared with model rats. TSD also adjusted the neurotransmitter levels, reduced the content of endothelin-1 (ET-1), and induced the activities of vascular endothelial growth factor (VEGF) in hippocampus. Moreover, the immunohistochemical staining and western blotting results also revealed that TSD decreased apoptosis via upregulated B-cell lymphoma-2 (Bcl-2)/Bcl-2 associated X protein (Bax) ratio. These results demonstrated TSD possesses neuroprotective and antidementia properties by preventing the loss of neural cells, adjusting brain neurotransmitter, promoting cerebral blood circulation, and decreasing apoptosis. These results suggested that TSD might be developed as an effective drug for the prevention of VD.