Determination of ibotenic acid and muscimol in wild mushroom by dansyl chloride derivatization-liquid chromatography-tandem mass spectrometry / 预防医学

Objective @#To develop an analytical method of ibotenic acid (IBA) and muscimol (MUS) in wild mushroom by dansyl chloride (DNSCl) derivatization-liquid chromatography-tandem mass spectrometry (LC-MS/MS), and to provide technical support for etiological identification of mushroom poisoning events.@*Methods @#The sample was extracted with hydrochloric acid solution, derived by bimolecular DNSCl, diluted and inorganic salts precipitated with acetonitrile. The extract was separated by a waters XBridgeTM BEH C18 column and measured by LC-MS/MS.@*Results @#The limits of detection for IBA and MUS in wild mushroom were 0.15 mg/kg and 0.1 mg/kg, respectively. Good linear relationship was obtained for IBA and MUS at the range of 0.5-250 mg/kg with the correlation coefficient of 0.997 and 0.999, respectively. The average recoveries at three spiking levels were 84.5%-102.0% with relative standard deviations (RSDs, n=6) of 4.7%-8.6% for IBA. The average recoveries were 88.6%-95.4% with RSDs (n=6) of 4.9%-7.5% for MUS. @*Conclusion @#The optimized sample extraction and bimolecular DNSCl derivatization conditions can achieve rapid and accurate analysis of IBA and MUS in wild mushroom poisoning sample.

Study on pharmacological effects and mechanism of Naozhifu as a new drug candidate for prevention and treatment of Alzheimer′s disease base on multiple targets strategy / 重庆医学

Objective To evaluate the effect of Naozhifu as a multifunctional agents for the prevention and treatment of Alzheimer’s disease(AD) .Methods On 30th after castration ,female mice were received intrahippocampal injection of Aβ1‐42 and ibotenic acid for replicating the AD model .On the next day ,these modeled mice were randomly divided into model group ,low dose of Naazhifu group ,middle dose of Naozhifu group ,high dose of Naozhifu group and piracetam group ,sham operated mice were set as control group .Then the gavage was given once a day for 4 consecutive weeks .Furthermore the step‐down passive avoidance test , morris water maze test and biochemical indicators detection were performed .Results In step‐down passive avoidance test ,the latent period in model group was significantly shortened(P<0 .05) ,the fault frequency was increased when compared with control group (P<0 .05) .During the Morris Water Maze test ,the latent period for seeking escape from platform in AD mice were obviously ex‐tended(P<0 .05) ,the times of passing through the platform was shortened(P<0 .05) ,the swimming path length around the escape from platform ,swimming time and distance in the effective area in AD mice were increased(P<0 .05) ,meanwhile the level of MDA in brain tissue was significantly increased ,while the levels of Ach and SOD were significantly decreased(P<0 .05) .These indicators in middle and high dose of Naofuzhi group obviously improved .Conclusion Naofuzhi has the multi‐target prevention and treatment effect on AD .

Effects of erythropoietin on neuron apoptosis and expression of caspase-3 after excitotoxic brain injury in mice during different developmental stages / 中华急诊医学杂志

Objective To investigate the effects of erythropoietin (EPO) on neuron apoptosis and expression of caspase-3 after excitotoxic brain injury induced by ibotenic acid (Ibo) in mice during different developmental stages.Methods A total of 144 healthy KM mice aged 7 d (n =48),21 d (n =48) and 42 d (n =48) were selected,and those of the same age were randomly (random number) divided into 3 groups:sham surgery group (n =16),Ibo group (n =16) and EPO treated group (n =16).Brain injury model was established by Ibo 1μl (5 μg) injected into left hippocampus.In EPO treated group,intraperitoneal injection of 5000 U/ (kg · d) EPO was performed for 3 consecutive days after injection of 1 μl Ibo into left hippocampus.Mice in sham surgery group and Ibo control group were treated with saline in the same dose instead.The pathological changes of neurons in hippocampus were observed 3 d after modeling in each group with Nissl staining,the level and activity of caspase-3 in hippocampus were determined by ABCELISA and spectrophotometry.Result After modeling,degeneration and death of neurons in hippocampuswith substantially decrease in number of intact neurons were found under light microscopy in Ibo group in comparison with sham surgery group.However,compared with the Ibo group,pathological changes in EPO treated group were less serious.The level of caspase-3 in Ibo control group was significantly higher than that in sham surgery group (P＜0.05),and the level of caspase-3 in EPO treated group was significantly lower than that in Ibo group (P ＜ 0.05).Conclusions The level of caspase-3 is significantly up-regulated in hippocampus of mice with Ibo-induced brain injury,leading to neuron apoptosis.EPO mitigates brain injury and plays a role of protection on brain function,suggesting the mechanism is attributed to decrease in caspase-3.

The anteromedial extrastriate complex is critical for the use of allocentric visual cues and in the retention of the Lashley III maze task in rats

The anteromedial extrastriate complex has been proposed to play an essential role in a spatial orientation system in rats. To gain more information about that possible role, in the present work, two questions were addressed: 1. Are allocentric visual cues relevant for acquisition of the orientation task in the Lashley III maze? 2. Is this integration of allocentric inputs in the anteromedial visual complex relevant in the retention of this test? While a control group of rats was trained keeping the maze in the same position, the experimental group was trained with the maze rotated counterclockwise by 144 degrees from session to session. Control rats reached learning criterion significantly earlier and with less errors than the experimental ones (p<.05). After 11 sessions, rats of both groups received stereotaxic injections of ibotenic acid in the anteromedial complex. In the retention test one week after surgery, the control group, which had been able to learn using egocentric and allocentric visual cues, showed a greater deficit than the experimental animals (p<.05). These results confirm the role of the anteromedial complex in the processing of visuospatial orientation tasks and demonstrate the integration of allocentric visual cues in the solution of those tasks.

Effect of a Rostral Basal Forebrain Lesion on Neuropeptide Containing Neurons in the Rat Cerebral Cortex / 대한해부학회지

The present study was designed to elucidate the effects of rostral basal forebrain lesions on neuropeptide containing neurons in the cerebral cortex. Nine male Sprague-Dawley rats[250-300gm] received bilateral injections of ibotenic acid into the basal forebrain[A : +0.7mm, L : 2.3mm, D : 8.6mm] and additional five served as sham operated animals. Brains were removed at 8-14 days after lesioning and frozen coronal sections of 40 micrometer thickness were made. Immunohistochemical staining was performed against the somatostatin[SOM], neuropeptide Y[NPY], and vasoactive intestinal polypeptide[VIP]. No differences were observed in the number of the SOM-immunoreactive[SOM-ir] or NPY-ir neurons between the lesioned and the control groups. Density of the NPY-ir fibers also did not show any significant difference between the two groups. In contrast, the number of VIP-ir neurons in the frontal cortex was significantly reduced following the basal forebrain lesioning. These results suggest the functional relationship between the basal forebrain and the cortical VIP-ir neurons.