The effects of agmatine on the apoptosis of immune cells in septic rats / 中华急诊医学杂志

Objective:By establishing the rats model of sepsis induced by endotoxin, exploring the effects of agmatine on the apoptosis of splenocyte and dendritic cells in the septic rats.Methods:SD rats ( healthy and clean, male, 90) were randomly(random number) divided into control groups, endotoxin groups and agmatine groups, 30 rats per group. The control groups were injected with normal saline via femoral vein (10 mL/kg), endotoxin groups were injected with lipopolysaccharide via femoral vein (10 mg/kg), agmatine groups were injected with lipopolysaccharide via femoral vein (10 mL/kg) and intraperitoneal injected of agmatine (200 mg/kg).The three groups were randomly selected 10 rats separately at 0 h, 12 h, 24 h (marked as 0 h, 12 h, 24 h subgroups, n=10) , anesthetized to death. Weigh the spleen; HE staining was used to observe the pathological changes of the spleen; The cell apoptosis of splenocyte and dendritic cells were detected by flow cytometry. The results were statistically analyzed using SPSS 17.0 software, analyzed by independent sample t test, P<0.05 was considered statistically significant. Results:The weights (g) of spleen in 12 h (1.2633±0.0652) , 24 h (1.5576±0.0711) subgroups of the endotoxin groups were increased significantly than the corresponding subgroups[(0.8876±0.0361),(0.9079±0.0425)]of the control groups ( P<0.05) , the 12 h (1.1052±0.0585) , 24 h (1.3262±0.0682) subgroups of the agmatine groups were decreased significantly than the corresponding subgroups of the endotoxin groups ( P<0.05) . HE staining showed that the spleen tissue inflammatory reaction in the endotoxin groups were worse than the control group ( P<0.05) , the agmatine groups were better than the endotoxin group ( P<0.05) . The apoptosis rates of the splenocyte[(13.31±1.26)、(19.53±1.68)]and dendritic cells[(19.5±1.52)、(16.09±1.15)]in the spleen from 12 h, 24 h subgroups of the endotoxin groups were significantly higher than the corresponding subgroups[(6.27±0.71),(6.01±0.67) and (4.99±0.51)、(5.30±0.66)]of the control groups ( P<0.05) , the 12 h[(9.19±0.95),(12.19±1.25)], 24 h [(12.71±1.19),(10.76±1.09)subgroups of the agmatine groups were significantly lower than the corresponding subgroups of the endotoxin groups ( P<0.05) ; The apoptosis rates of the splenocyte in the 24 h subgroups of the endotoxin groups and the agmatine groups were significantly higher than the 12 h subgroups of the same group ( P<0.05) , but the apoptosis rates of the dendritic cells were significantly lower than the 12h subgroups of the same group ( P<0.05) . Conclusion:The apoptosis of splenocyte and dendritic cells were closely related to the occurrence and development of sepsis, Agmatine could inhibit the apoptosis of splenocyte and dendritic cells the rats with sepsis.

Analgesic effect of gabapentin combined with agmatine on neuropathic pain in diabetic rats / 国际药学研究杂志

Objective: To investigate analgesic effect of gabapentin(GBP)combined with agmatine(AGM)on diabetic neuropathic pain(DNP)model rats and explore possible mechanism. Methods: SPF SD male rats were injected intraperitoneally with STZ 65 mg/kg to create a neuropathic pain model of diabetic rats. The model rats were randomly divided into 5 groups(n=8): the model group, low-dose GBP group(30 mg/kg, ip), high-dose GBP group(100 mg/kg, ip), AGM group(80 mg/kg, ig)and the GBP-AGM combined group(GBP 30 mg/kg, ip+AGM 80 mg/kg, ig). In addition, a control group was set with 8 randomly selected normal rats. The control group and the model group were intragastrically and intraperitoneally administered an equal volume of physiological saline, respectively, while the test groups were administered drugs with the given dose in the indicated manner, all for continuous 14 days. The rat body mass, tail vein blood glucose, mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL) were measured on day 1 before STZ injection and every 7th day after STZ injection, and the plantar tenderness meter was used for the MWT and TWL measurement. The rats were sacrificed 24 h after the last administration, and the spinal cord tissues were harvested. Western blotting was used to detect the expression of p-ERK and c-Fos protein in spinal cord tissues. Results: Compared with the normal control group, the body mass was reduced, blood glucose increased, MWT decreased, and TWL shortened in the model group, all significantly(P0.05)in all of the drug-test groups, while the MWT was increased and the TWL was prolonged in the GBP 100 mg/kg group and the GBP-AGM combined group(both P<0.01). Western blotting results showed that the level of p-ERK and c-Fos protein in the spindal cord was significantly higher in the model group than in the control group(P<0.05). Further, the p-ERK and c-Fos protein level was significantly lower in the GBP+AGM combined group than in the model group(P<0.05)and there was no statistical difference between the GBP 100 mg/kg group and the GBP-AGM combination group. Conclusion: The combination of GBP 30 mg/kg with AGM 80 mg/kg could alleviate neuropathic pain in diabetic rats, which is similar to GBP 100mg/kg and the analgesic effect is likely related to the inhibition of ERK/c-Fos signaling pathway in the spina cord.

Effect of agmatine on apoptosis of type Ⅱ alveolar epithelial cells in rats with hyperoxia-induced acute lung injury / 中国中西医结合急救杂志

Objective To investigate the effects of agmatine (AGM) on the apoptosis of type Ⅱ alveolar epithelial cells (AECⅡ) in rats with hyperoxia-induced acute lung injury (HALI) and provide a theoretical basis for the treatment of HALI. Methods A total of 24 Sprague-Dawley (SD) rats were randomly divided into three groups:normal control group (fed in air), HALI model group and AGM pretreatment group (400 mg/kg AGM was given before the hyperoxia treatment or HALI model establishment), each group with 8 rats. The rats were placed in a self-made high oxygen model box with oxygen concentration of > 90%, temperature of 25-27 ℃, humidity of 50%-70% and carbon dioxide concentration < 0.5% to replicate the HALI rat model; no any treatment was given to the normal control group. After the hyperoxia was treated for 48 hours, the arterial blood was taken from the rat carotid artery for blood gas analysis;under light microscope, the pathological changes of lung tissues were observed and the pathological evaluation scores were carried out; the contents of tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1) in bronchoalveolar lavage fluid (BALF) were detected by enzyme-linked immunosorbent assay (ELISA); the apoptosis of AECⅡ of lung tissues was determined by flow cytometry, and the apoptotic rate was calculated; the expressions of the apoptosis related protein Bcl-2 and Bax were detected by Western Blot. Results Compared with the normal control group, the oxygenation index (OI) and Bcl-2 of HALI model group and AGM pretreatment group were significantly decreased [OI (mmHg, 1mmHg = 0.133 kPa): 135.04±16.82 vs. 463.74±22.04, Bcl-2 protein expression (A value): 0.35±0.18 vs. 0.89±0.08], while the respiratory index (RI), pathological scores of lung injury, TNF-α, IL-6, IL-1, the apoptosis rate of AECⅡ, Bax protein expression were all significantly increased [RI: 1.29±0.15 vs. 0.24±0.03, pathological score of lung tissue: 4.72±1.32 vs. 0, TNF-α (μg/L): 44.48±1.42 vs. 14.12±0.88, IL-6 (μg/L): 51.46±1.62 vs. 23.20±0.89, IL-1 (μg/L): 44.03±2.45 vs. 11.64±1.34, apoptosis rate of AECⅡ: (56.24±1.14)% vs. (22.64±0.58)%, Bax protein expression (A value): 2.37±0.34 vs. 1.41±0.48, all P < 0.05]. Compared with HALI model group, the OI and Bcl-2 of AGM pretreatment group were significantly increased [OI (mmHg): 364.72±14.56 vs. 135.04±16.82, Bcl-2 protein expression (A value): 0.68±0.10 vs. 0.35±0.18, all P < 0.05], while the RI, pathological scores of lung injury, TNF-α, IL-6, IL-1, apoptosis rate of AECⅡ, and Bax protein expression were significantly decreased [RI: 0.45±0.09 vs. 1.29±0.15, pathological score of lung tissue: 2.30±0.96 vs. 4.72±1.32, TNF-α (μg/L):22.98±0.72 vs. 44.48±1.42, IL-6 (μg/L): 35.79±0.86 vs. 51.46±1.62, IL-1 (μg/L): 24.06±0.86 vs. 44.03±2.45, apoptosis rate of AECⅡ: (28.58±1.21)% vs. (56.24±1.14)%, Bax protein expression (A value): 1.98±0.42 vs. 2.37±0.34, all P < 0.05]. Conclusion The apoptotic rate of AECⅡ in HALI rats is reduced by AGM, and the regulatory mechanism needs to be further studied.

Pre-column derivation method and evaluation of agmatine / 国际检验医学杂志

Agmatine is an endogenous amine synthesized from the decarboxylation of arginine.It has a rich biological effects and presents in plants, bacteria and mammalian tissues.Agmatine is highly polar and has a low molecular weight.There are no UV and fluorescent absorption groups in agmatine structure, so it is difficult to gasify.In addition, the content of endogenous agmatine is low, and there are many interference components in biological samples, and the general method is difficult to detect.The pre-column derivatization of agmatine with fluorescence reagents not only increase the molecular weight of agmatine, but also make them with fluorescence, which greatly improve the detection sensitivity and enable the endogenous agmatine to be well separated.It is an important method to determine the content of agmatine.In this paper, several kinds of precolumn derivatives are summarized, and the advantages and disadvantages of various derivatives, the best derivation conditions and detection methods were also analyzed comprehensively.The aim is to determine the content of agmatine and to provide methods and ideas for its biological research.

Role of Agmatine on Neuroglia in Central Nervous System Injury

Recovery from central nervous system (CNS) injury, such as stroke or spinal cord injury (SCI), largely depends on axonal regeneration, and the neuronal and glial cells plasticity in the lesioned tissue. The lesioned tissue following CNS injury forms a scar that is composed of astrocytes and mixed with connective tissues. At the glial scar, the regenerating axon forms dystrophic endbulbs which do not regenerate and grow beyond the glial scar without a suitable environment. Along with the astrocytes, microglia are also suspected of being involved in necrotic and apoptotic neuronal cell death and the early response to axonal damage in CNS injury. The inflammatory response, a major component of secondary injury and controlled by the microglia, plays a pivotal role in nerve injury and control the regenerative response. As a result, it is very important to control the glial cell function in order to assure the recovery of the CNS injury. Studies have suggested that agmatine, a L-arginine derived primary amine, is a potential modulator of glial cell function after CNS injuries. Agmatine was found to possess anti-inflammatory and neuroprotective characteristics that benefited the rehabilitation process following CNS injury. In this review, we will discuss the effect of agmatine on glial cells in the process of recovery after CNS injury.

Enzymatic production of arginine derivatives: a review / 生物工程学报

L-arginine (L-Arg) is an alkaline amino acid that possesses various function groups and acts as an important precursor for useful chemical synthesis. L-Arg derivatives are widely applied in pharmaceutical, food and cosmetic industries. Environment friendly and cost-effective production of L-Arg derivatives by enzymatic catalysis provides significant advantages over chemical synthesis and microbial fermentation. In this article, several typical L-Arg derivatives and their enzymatic production processes are highlighted. Furthermore, prospect is also addressed about enzymatic production of L-Arg derivatives.

Agmatine Modulates the Phenotype of Macrophage Acute Phase after Spinal Cord Injury in Rats

Agmatine is a decarboxylated arginine by arginine decarboxylase. Agmatine is known to be a neuroprotective agent. It has been reported that agmatine works as a NMDA receptor blocker or a competitive nitric oxide synthase inhibitor in CNS injuries. In spinal cord injury, agmatine showed reduction of neuropathic pain, improvement of locomotor function, and neuroprotection. Macrophage is a key cellular component in neuroinflammation, a major cause of impairment after spinal cord injury. Macrophage has subtypes, M1 and M2 macrophages. M1 macrophage induces a pro-inflammatory response, but M2 inspires an anti-inflammatory response. In this study, it was clarified whether the neuroprotective effect of agmatine is related with the modulation of macrophage subdivision after spinal cord injury. Spinal cord injury was induced in rats with contusion using MASCIS. Animals received agmatine (100 mg/kg, IP) daily for 6 days beginning the day after spinal cord injury. The proportion of M1 and M2 macrophages are confirmed with immunohistochemistry and FACS. CD206+ & ED1+ cells were counted as M2 macrophages. The systemic treatment of agmatine increased M2 macrophages caudal side to epicenter 1 week after spinal cord injury in immunohistochemistry. M2 macrophage related markers, Arginase-1 and CD206 mRNA, were increased in the agmatine treatment group and M2 macrophage expressing and stimulated cytokine, IL-10 mRNA, also was significantly overexpressed by agmatine injection. Among BMPs, BMP2/4/7, agmatine significantly increased only the expression of BMP2 known to reduce M1 macrophage under inflammatory status. These results suggest that agmatine reduces impairment after spinal cord injury through modulating the macrophage phenotype.

Endogenous Agmatine Induced by Ischemic Preconditioning Regulates Ischemic Tolerance Following Cerebral Ischemia

Ischemic preconditioning (IP) is one of the most important endogenous mechanisms that protect the cells against ischemia-reperfusion (I/R) injury. However, the exact molecular mechanisms remain unclear. In this study, we showed that changes in the level of agmatine were correlated with ischemic tolerance. Changes in brain edema, infarct volume, level of agmatine, and expression of arginine decarboxylase (ADC) and nitric oxide synthases (NOS; inducible NOS [iNOS] and neural NOS [nNOS]) were analyzed during I/R injury with or without IP in the rat brain. After cerebral ischemia, brain edema and infarct volume were significantly reduced in the IP group. The level of agmatine was increased before and during ischemic injury and remained elevated in the early reperfusion phase in the IP group compared to the experimental control (EC) group. During IP, the level of plasma agmatine was increased in the early phase of IP, but that of liver agmatine was abruptly decreased. However, the level of agmatine was definitely increased in the ipsilateral and contralateral hemisphere of brain during the IP. IP also increased the expression of ADC—the enzyme responsible for the synthesis of endogenous agmatine—before, during, and after ischemic injury. In addition, ischemic injury increased endogenous ADC expression in the EC group. The expression of nNOS was reduced in the I/R injured brain in the IP group. These results suggest that endogenous increased agmatine may be a component of the ischemic tolerance response that is induced by IP. Agmatine may have a pivotal role in endogenous ischemic tolerance.

The effects of agmatine on acute peritoneal inflammatory injury and neutrophil infiltration induced by zymosan in mice / 中华危重病急救医学

Objective To investigate the protective effect of agmatine (AGM) against peritoneal inflammatory response and neutrophil (PMN) infiltration induced by zymosan (ZYM) in mice. Methods Thirty-six adult male C57BL/6 mice were randomly divided into sham group, model group, and AGM treatment group. Peritonitis model was reproduced by intra-peritoneal injection of 1 mg/mL ZYM (0.5 mL), while equivalent phosphate buffer saline (PBS) was given to sham group. 200 mg/kg AGM was injected into peritoneal cavity after ZYM challenge in AGM treatment group. Six mice in each group were sacrificed at 2 hours and 6 hours, respectively, after reproduction of the model. Blood sample and peritoneal lavage fluid (PLF) were collected. The levels of keratinocyte-derived chemokine (KC), macrophage inflammatory protein 2 (MIP-2), tumor necrosis factor-α (TNF-α), interleukins-6 (IL-6) in serum and PLF were determined by enzyme linked immunosorbent assay (ELISA). The number of leukocytes and PMN in PLF were determined by hemocytometer and flow cytometry, respectively. Results Compared with sham group, all serum and PLF levels of KC, MIP-2, TNF-α and IL-6 were greatly elevated at 2 hours after ZYM injection in model group, while AGM treatment could dramatically reduce the levels of the above-mentioned cytokines in serum and PLF as compared with those of the model group [serum KC (ng/L): 990.7±137.9 vs. 2 053.2±262.7, MIP-2 (ng/L): 642.2±124.4 vs. 1 369.7±146.5, TNF-α (ng/L): 608.6±38.1 vs. 1 044.7±101.0, IL-6 (ng/L): 1 058.2±129.1 vs. 1 443.3±190.1; PLF KC (ng/L): 7 462.3±839.6 vs. 12 723.5±1 515.7, MIP-2 (ng/L): 1 570.8±193.4 vs. 3 471.4±384.7, TNF-α (ng/L): 1 115.8±156.7 vs. 1 499.2±231.2, IL-6 (ng/L): 2 646.5±223.2 vs. 3 126.7±291.4; all P < 0.05]. The expressions of KC, MIP-2 and TNF-α at 6 hours were significantly lower than those at 2 hours in model group and AGM treatment group, but IL-6 levels were further increased. The levels of KC and MIP-2 in serum and PLF at 6 hours were decreased to the levels of sham group. At 6 hours after the reproduction of the model, the number of total inflammatory cells and PMN of PLF in the model group was significantly higher than those of the sham group. In contrast, AGM notably lowered the number of inflammatory cells and PMN in peritoneal fluid after ZYM attack [total inflammatory cells (×109/L): 14.7±1.1 vs. 2.0±0.4, 10.1±1.2 vs. 14.7±1.1; PMN (×109/L): 11.37±1.22 vs. 0.18±0.05, 7.69±0.57 vs. 11.37±1.22, all P < 0.05]. Conclusion AGM can effectively alleviate acute peritoneal inflammatory injury induced by ZYM, mainly through reducing the secretion of inflammatory mediators and chemokines, and inhibiting the infiltration of leukocytes and neutrophils.

Protective effects of agmatine on severe trauma induced acute hepatic injury / 中华危重病急救医学

Objective To observe the effect of agmatine (AGM) on inflammatory factor in Kupffer cells of liver,and to investigate the protective effects of AGM on severe trauma-induced liver injury in mice and its possible mechanism.Methods Forty-two adult male BALB/c mice were randomly divided into sham group,model group,and AGM treatment group,with 14 mice in each group.The mice model of trauma-hemorrhage was reproduced by hindlimbs fracture combined with 35％ of orbital bleeding.The mice in the sham group were only anesthetized without other treatments.The mice in AGM treatment group were given intraperitoneal injection of 200 mg/kg AGM when limited recovery was performed,and the mice in model group were given the equal amount of normal saline.Seven mice in each group were sacrificed at 12 hours and 24 hours,respectively,after modeling,and blood samples and liver tissue were harvested,and liver Kupffer cells were isolated.Serum alanine aminotransferase (ALT),aspartate transaminase (AST)and lactic dehydrogenase (LDH) were determined with automatic biochemistry analyzer.Hepatic pathological changes were observed with light microscope using hematoxylin and eosin (HE) staining.The levels of tumor necrosis factor-α(TNF-o) and interleukin-6 (IL-6) in serum,hepatic homogenate and Kupffer cell supernatant were determined with enzyme linked immunosorbent assay (ELISA).The mRNA expressions of pro-inflammatory cytokines TNF-α and IL-6 in the Kupffer cell were determined by real-time fluorescent quantitation reverse transcription-polymerase chain reaction (RT-qPCR).Results ① The normal liver tissue structure was found in sham group.At 24 hours after modeling in the model group,the changes in pathobiology were found as following:neutrophil infiltration,hepatocytes swelling,hyperemia,and necrosis,as well as the abnormality of parameters reflecting liver function.AGM could significantly improve the pathological changes in liver tissue caused by severe trauma,and ameliorate the liver function.② There were no significant differences in the levels of TNF-α and IL-6 in serum and hepatic tissue at 12 hours after modeling,and the parameters at 24 hours in model group were higher than those at 12 hours,which were significantly higher than those of the sham group [serum TNF-α (ng/L):80.8±4.7 vs.34.7±4.7,IL-6 (ng/L):104.0±9.0 vs.55.4±3.3;liver TNF-α (ng/mg):405.2± 19.6 vs.57.2±10.0,IL-6 (ng/mg):58.4±7.7 vs.14.3±2.1,all P ＜ 0.01].AGM could effectively reduce the levels of TNF-o and IL-6 in serum and hepatic tissue [serum TNF-α (ng/L):58.2 ± 3.1 vs.80.8 ± 4.7,IL-6 (ng/L):74.1 ± 6.6 vs.104.0± 9.0;liver TNF-α (ng/mg):248.7 ± 22.5 vs.405.2 ± 19.6,IL-6 (ng/mg):22.5 ± 3.1 vs.58.4 ± 7.7,all P ＜ 0.01].③ The levels of TNF-o and IL-6 in Kupffer cells supernatant were significantly higher than those of the sham group,and they were further increased after lipopolysaccharide (LPS) stimulation for 24 hours.AGM could effectively reduce the levels of TNF-α and IL-6 in Kupffer cells [TNF-α (ng/L):256.6 ± 5.6 vs.465.5 ± 5.2,IL-6 (ng/L):1 185.5 ± 64.4 vs.2 018.8 ± 53.2,both P ＜ 0.01],and also decreased the mRNA expressions of TNF-α and IL-6 [TNF-α mRNA (2-△△Ct):7.2±0.4 vs.13.5±0.4,IL-6 mRNA (2-△△Ct):13.2±0.7 vs.21.3 ± 1.6,both P ＜ 0.01].Conclusion Agmatine can reduce trauma-induced acute hepatic injury via suppression of cytokines release in Kupffer cells,and can ameliorate the liver function.

Agmatine protection against chlorpromazine-induced forebrain cortex injury in rats

This study was conducted to investigate whether agmatine (AGM) provides protection against oxidative stress induced by treatment with chlorpromazine (CPZ) in Wistar rats. In addition, the role of reactive oxygen species and efficiency of antioxidant protection in the brain homogenates of forebrain cortexes prepared 48 h after treatment were investigated. Chlorpromazine was applied intraperitoneally (i.p.) in single dose of 38.7 mg/kg body weight (BW) The second group was treated with both CPZ and AGM (75 mg/kg BW). The control group was treated with 0.9% saline solution in the same manner. All tested compounds were administered i.p. in a single dose. Rats were sacrificed by decapitation 48 h after treatment Treatment with AGM significantly attenuated the oxidative stress parameters and restored antioxidant capacity in the forebrain cortex. The data indicated that i.p. administered AGM exerted antioxidant action in CPZ-treated animals. Moreover, reactive astrocytes and microglia may contribute to secondary nerve-cell damage and participate in the balance of destructive vs. protective actions involved in the pathogenesis after poisoning.

Agmatine Ameliorates High Glucose-Induced Neuronal Cell Senescence by Regulating the p21 and p53 Signaling

Neuronal senescence caused by diabetic neuropathy is considered a common complication of diabetes mellitus. Neuronal senescence leads to the secretion of pro-inflammatory cytokines, the production of reactive oxygen species, and the alteration of cellular homeostasis. Agmatine, which is biosynthesized by arginine decarboxylation, has been reported in previous in vitro to exert a protective effect against various stresses. In present study, agmatine attenuated the cell death and the expression of pro-inflammatory cytokines such as IL-6, TNF-alpha and CCL2 in high glucose in vitro conditions. Moreover, the senescence associated-beta-galatosidase's activity in high glucose exposed neuronal cells was reduced by agmatine. Increased p21 and reduced p53 in high glucose conditioned cells were changed by agmatine. Ultimately, agmatine inhibits the neuronal cell senescence through the activation of p53 and the inhibition of p21. Here, we propose that agmatine may ameliorate neuronal cell senescence in hyperglycemia.

Suppression of MicroRNA let-7a Expression by Agmatine Regulates Neural Stem Cell Differentiation

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.

Suppression of MicroRNA let-7a Expression by Agmatine Regulates Neural Stem Cell Differentiation

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.

Effect of agmatine co-administration with yohimbine on morphine-induced behavioral sensitization in mice / 国际药学研究杂志

Objective To investigate the effect of agmatine or agmatine combined with yohimbine on morphine-induced psychological dependence in mice. Methods 1. Testing the effect of agmatine or agmatin combined with yohimbine on basal locomotor activity in 60 minutes. C57BL/6J male mice were divided into four groups: control group, agmatine (1,10,20,40 and 80 mg/kg) groups, yohimbine (0.3,1,2 and 8 mg/kg) groups and yohimbine (2 mg/kg) + agmatine (80 mg/kg) group. 2. Testing theeffects of drug pretreatment on morphine-induced hyperlocomotion in 60 minutes. Mice were divided into five groups: control group, morphine (10 mg/kg) group, agmatine (1,20 and 80 mg/kg) + morphine (10 mg/kg) group,yohimbine (2 mg/kg) + morphine (10 mg/kg) group and yohimbine (2 mg/kg) + agmatine (80 mg/kg) + morphine (10 mg/kg) group. 3. Observing the effects of agmatine or agmatine combined with yohimbine on morphine induced behavioral sensitization. The mice were administrated with morphine (10 mg/kg) on the 1st , 4th and 7th day and the locomotor activity of mice was recorded for 60 minutes. Mice were divided into four groups: control group, morphine (10 mg/kg) group, agmatine (1,20 and 80 mg/kg) + morphine (10 mg/kg) groups and yohimbine (2 mg/kg) + agmatine (80 mg/kg) + morphine (10 mg/kg) group. Results Our present study showed that agmatine (1-80 mg/kg) or yohimbine (0.3-2 mg/kg), a selective antagonist of a2-adrenoceptor, had no significant effect on basal locomotor and acute morphine-induced hyperlocomotion compared with those of control group. However, the distance in the group of agmatine combined with yohimbine followed by morphine for 60 min was (22 581.6&11 694.0) cm, which was significantly lower than the acute morphine group(37 577.9±9 657.4) cm(#<0.05). In the mophine-induced behavioral sensitization model, agmatine (1,20 and 80 mg/kg) alone had no effect on morphine-induced development of behavioral sensitization in mice. But, the combination of the two drugs significantly attenuated morphine-induced behavioral sensitization. The locomotor activities in the combination treatment groups were (21 112.7±5 586.7) cm, (37 672.7±10 518.8) cm and 47 681.0±15 845.3 cm, which were lower than those of morphine group (31 156.4&8 010.5) cm(#<0.01), (51 724.9&11 364.51) cm (P<0.05) and (63 572.2&12 151.2) cm (P<0.05) on the 1st , 4th and 7th day of experiment, respectively. Conclusion Our current results demonstrated that agmatine combined with yohimbine could decrease morphine-induced psychological dependence in mice. It may provide a new strategy for psychological dependence of morphine.

Effects of agmatine on excessive inflammatory reaction and proliferation of splenic cells in mice with trauma / 中华危重病急救医学

ObjectiveTo observe protective effects of agmatine (AGM) on inflammatory response and spleen immune function in mice with trauma.Methods Forty-eight adult male C57BL/6 mice were randomly divided into three groups (n= 16 each), including control group, model group (bilateral femoral fracture and removal of 35% of the total blood volume), and AGM group (trauma/hemorrhage & AGM 200 mg/kg). Eight mice in each group were sacrificed at 3 hours and 24 hours, respectively, after modeling, and blood samples and tissue homogenate of spleen and liver were collected. The contents of tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-1β) in serum and liver tissue were determined with enzyme linked immunosorbent assay (ELISA). Serum aspartate transaminase (AST), alanine aminotransferase (ALT) and lactic dehydrogenase (LDH) were determined with automatic biochemistry analyzer. Spleen proliferation response stimulated with concanavalin A (ConA) was evaluated with methyl thiazolyl tetrazolium colourimetry (MTT).γ-interferon (IFN-γ) and IL-2 releases were determined with ELISA.Results Compared with control group, 3 hours after trauma/hemorrhage, the levels of serum TNF-α, IL-6, and IL-1β in model group were significantly elevated [TNF-α (ng/L): 145.38±31.50 vs. 23.06±11.14, IL-6 (ng/L): 496.94±50.76 vs. 47.13±17.47, IL-1β (ng/L): 321.31±43.02 vs. 29.25±16.24,allP< 0.01]. It was found that AGM treatment could alleviate the increase in serum pro-inflammatory mediators induced by trauma/hemorrhage, such as TNF-α (ng/L:111.56±25.47 vs. 145.38±31.50), IL-6 (ng/L: 412.56±44.33 vs. 496.94±50.76), IL-1β (ng/L: 273.38±45.25 vs. 321.31±43.02,P< 0.05 orP< 0.01). Twenty-four hours after trauma/hemorrhage, serum pro-inflammatory mediators were recovered to the levels in control group. There was no significant difference in TNF-α and IL-6 levels at 3 hours after trauma/hemorrhage among groups. Compared with control group, the expressions of liver TNF-α and IL-6 in model group were increased at 24 hours following trauma [TNF-α (ng/mg): 32.93±4.90 vs. 26.58±2.33, IL-6 (ng/mg): 11.20±1.66 vs. 8.38±0.89,bothP< 0.01]. However, AGM inhibited the level of TNF-α (ng/mg:28.92±3.16 vs. 32.93±4.90) and IL-6 (ng/mg: 9.03±1.28 vs. 11.20±1.66) in the liver as induced by trauma/hemorrhage (P< 0.05 andP< 0.01). At 24 hours after modeling, model group and AGM group had distinctly higher serum AST, ALT, LDH levels than those of control group [AST (U/L): 405.9±31.2, 245.7±22.1 vs. 128.2±15.9; ALT (U/L): 92.1±6.3, 51.6±5.0 vs. 30.1±3.2; LDH (U/L): 606.7±36.3, 478.7±25.3 vs. 384.0±16.6, allP< 0.01]. Nevertheless,the increase in serum AST, ALT and LDH was alleviated in AGM group (allP< 0.01). Meantime, trauma/hemorrhage produced a noticeable depression of proliferation of splenic cells and IFN-γ and IL-2 release stimulated with ConA compared with control group [proliferation rate: (40.97±4.13)% vs. (89.99±7.76)%, IFN-γ(ng/L): 91.6±12.3 vs. 353.2±21.5,IL-2 (ng/L): 53.4±6.4 vs. 91.0±12.2,allP< 0.01]. In contrast, AGM notably restored the capacity of proliferation response of splenic cells [proliferation rate: (74.86±5.75)% vs. (40.97±4.13)%, P< 0.01],enhanced the release of IFN-γ and IL-2 stimulated with ConA [IFN-γ (ng/L): 327.8±23.6 vs. 91.6±12.3, IL-2 (ng/L): 74.8±10.4 vs. 53.4±6.4, bothP< 0.01].Conclusion AGM can dramatically alleviate spleen immunosuppression, excessive inflammation and organ damage induced by trauma/hemorrhage.

Agmatine Attenuates Brain Edema and Apoptotic Cell Death after Traumatic Brain Injury

Traumatic brain injury (TBI) is associated with poor neurological outcome, including necrosis and brain edema. In this study, we investigated whether agmatine treatment reduces edema and apoptotic cell death after TBI. TBI was produced by cold injury to the cerebral primary motor cortex of rats. Agmatine was administered 30 min after injury and once daily until the end of the experiment. Animals were sacrificed for analysis at 1, 2, or 7 days after the injury. Various neurological analyses were performed to investigate disruption of the blood-brain barrier (BBB) and neurological dysfunction after TBI. To examine the extent of brain edema after TBI, the expression of aquaporins (AQPs), phosphorylation of mitogen-activated protein kinases (MAPKs), and nuclear translocation of nuclear factor-kappaB (NF-kappaB) were investigated. Our findings demonstrated that agmatine treatment significantly reduces brain edema after TBI by suppressing the expression of AQP1, 4, and 9. In addition, agmatine treatment significantly reduced apoptotic cell death by suppressing the phosphorylation of MAPKs and by increasing the nuclear translocation of NF-kappaB after TBI. These results suggest that agmatine treatment may have therapeutic potential for brain edema and neural cell death in various central nervous system diseases.

Effect of agmatine co-administration with yohimbine on morphine-induced behavioral sensitization in mice / 国际药学研究杂志

Objective To investigate the effect of agmatine or agmatine combined with yohimbine on morphine-induced psychological dependence in mice. Methods 1. Testing the effect of agmatine or agmatin combined with yohimbine on basal locomotor activity in 60 minutes. C57BL/6J male mice were divided into four groups:control group, agmatine (1,10,20,40 and 80 mg/kg) groups, yohimbine(0.3,1,2 and 8 mg/kg) groups and yohimbine(2 mg/kg)+ agmatine(80 mg/kg) group. 2. Testing the effects of drug pretreatment on morphine-induced hyperlocomotion in 60 minutes. Mice were divided into five groups: control group, morphine(10 mg/kg) group, agmatine(1,20 and 80 mg/kg)+ morphine(10 mg/kg) group,yohimbine(2 mg/kg)+ morphine(10 mg/kg) group and yohimbine(2 mg/kg)+ agmatine(80 mg/kg)+ morphine(10 mg/kg) group. 3. Observing the effects of agmatine or agmatine combined with yohimbine on morphine induced behavioral sensitization. The mice were administrated with morphine(10 mg/kg) on the 1st , 4th and 7th day and the locomotor activity of mice was recorded for 60 minutes. Mice were divided into four groups: control group, morphine(10 mg/kg) group, agmatine(1,20 and 80 mg/kg) + morphine(10 mg/kg) groups and yohimbine (2 mg/kg)+ agmatine(80 mg/kg)+ morphine(10 mg/kg) group. Results Our present study showed that agmatine(1-80 mg/kg) or yohimbine (0.3-2 mg/kg), a selective antagonist of α2-adrenoceptor, had no significant effect on basal locomotor and acute morphine-induced hyperlocomotion compared with those of control group. However, the distance in the group of agmatine combined with yohimbine followed by morphine for 60 min was(22 581.6±11 694.0) cm,which was significantly lower than the acute morphine group(37 577.9±9 657.4)cm(P<0.05). In the mophine-induced behavioral sensitization model, agmatine(1,20 and 80 mg/kg) alone had no effect on morphine-induced development of behavioral sensitization in mice. But, the combination of the two drugs significantly attenuated morphine-induced behavioral sensitization. The locomotor activities in the combination treatment groups were (21 112.7±5 586.7)cm,(37 672.7±10 518.8)cm and(47 681.0±15 845.3)cm, which were lower than those of morphine group (31 156.4±8 010.5) cm(P<0.01),(51 724.9±11 364.51)cm(P<0.05) and(63 572.2±12 151.2) cm(P<0.05) on the 1st , 4th and 7th day of experiment, respectively. Conclusion Our current results demonstrated that agmatine combined with yohimbine could decrease morphine-induced psychological dependence in mice. It may provide a new strategy for psychological dependence of morphine.

Effects of agmatine on permeability of blood-brain barrier and expression of aquaporin 4 and matrix metalloproteinase 9 / 中华行为医学与脑科学杂志

Objective To investigate the protection of agmatine on blood brain barrier (BBB) permeability and the effect on the expression of aquaporin 4 (AQP4) and matrix metalloproteinase 9 (MMP9) in ischemic reperfusion injury rats.Methods Sixty healthy male Sprague-Dawley rats were randomly divided into normal control group (NC),model group and agmatine group,and there were 20 rats in each group.Normal control group was treated with intraperitoneal injection of saline in 2 hours after incision and suture of skin.Model group was treated with intraperitoneal injection of saline in 2 hours after the establishment of middle cerebral artery occulation (MCAO) model.Agmatine group was treated with intraperitoneal injection of agmatine (AGM) in 2 hours after the establishment of MCAO model.The damage of blood brain barrier was detected by measuring the permeability of blood brain barrier.The infarct size of brain was observed with TTC staining.The morphological changes of neurons were observed with electron microscope.The expressions of AQP4 and MMP9 were detected using immunohistochemical method.Results The permeability of BBB of agmatine treatment group (0.31±0.10) decreased significantly compared with the model group (0.46±0.09) (P＜0.05),but was still significantly higher than the normal control group (0.24±0.12) (P＜0.05).There was no infarction area in normal control group and the infarction areas of agmatine group decreased obviously compared with the model group.Compared with model group,the number of neurons with morphological changes reduced significantly and the degree of pathological changes of neurons was obviously improved in agmatine group.Compared with normal control group,the expression of AQP4 and MMP9 in ischemic penumbra of left cerebral hemisphere parietal cortex in the rats of model group and agmatine group increased significantly(P＜0.05).And the expression of AQP4 and MMP9 in model group was significantly higher than that of agmatine group(P＜0.05).Conclusion Agmatine has a protective effect on BBB with ischemia-reperfusion injury due to its down-regulation the expression of AQP-4 and MMP-9.

Effect of agmatine on intrathecal morphine analgesia / 第二军医大学学报

Objective To observe the effect of intrathecal agmatine(AG) at the spinal cord level on morphine tolerance. Methods (1) Twenty-four SD rats were divided into four groups: control group, pure intrathecal injection(i.t.) of saline(15 μL); morphine group, i.t. morphine(15 μg/15 μL); AG group, i.t. AG (12.5 μg/15 μL); and morphine+AG group, i.t. morphine (15 μg/5 μg) and AG (12.5 μg/10 μL). Rats of the four groups were injected with 0.2 mg bee venom subcutaneously in the plantar 5 min after i.t, and the numbers of spontaneous paw withdrawal reflex were recorded within 1 hour. (2) Twenty-four SD rats were divided into three groups: control group, pure intrathecal saline(15 μL); morphine tolerance group, i.t. morphine(15 μg/5 μL) twice a day for 4 consecutive days; and morphine tolerance+AG group, i.t. morphine(15 μg/5 μL)twice a day for 4 consecutive days, on the fourth day the rats also received AG(12.5 μg/10 μL). Half of the rats were examined for thermal paw withdrawal latency and mechanical withdrawal threshold after i.t, and the other half was injected with 0.2 mg bee venom subcutaneously in the plantar 10 min after last dose; the number of spontaneous paw withdrawal reflex were recorded within 1 hour. Results (1)Compared with the control group, the numbers of flinches of intrathecal morphine and AG groups were significantly reduced(P<0.05). (2) In intrathecal morphine tolerance model, the thermal paw withdrawal latency and mechanical withdrawal threshold were significantly increased in the morphine tolerance+AG group compared with the control group (P<0.05);morphine tolerance + AG group had significantly stronger inhibitory effect against spontaneous s.c. BV-induced pain, with the number of spontaneous flinches within 1 hour decreased significantly in the morphine tolerance + AG group(P<0.05). Conclusion Intrathecal AG has synergistic effect with morphine in pain relieving, and it can also reverse the morphine tolerance induced by repeated i.t. injection.