OBJECTIVETo study the toxicity of methomyl to acetylcholinesterase (AChE) in different regions.

METHODSThe optimal temperature and time for measurement of AChE activity were determined in vitro. The dose- and time-response relationships of methomyl with AChE activity in human erythrocyte membrane, rat erythrocyte membrane, cortical synapses, cerebellar synapses, hippocampal synapses, and striatal synapses were evaluated. The half maximal inhibitory concentration (IC50) and bimolecular rate constant (K) of methomyl for AChE activity in different regions were calculated, and the type of inhibition of AChE activity by methomyl was determined.

RESULTSAChE achieved the maximum activity at 370 °C, and the optimal time to determine initial reaction velocity was 0-17 min. There were dose- and time-response relationships between methomyl and AChE activity in the erythrocyte membrane and various brain areas. The IC50 value of methomyl for AChE activity in human erythrocyte membrane was higher than that in rat erythrocyte membrane, while the Ki value of methomyl for AChE activity in rat erythrocyte membrane was higher than that in human erythrocyte membrane. Among synapses in various brain areas, the striatum had the highest IC50 value, followed by the cerebellum, cerebral cortex, and hippocampus, while the cerebral cortex had the highest Ki value, followed by the hippocampus, striatum, and cerebellum. Lineweaver-Burk diagram demonstrated that with increasing concentration of methomyl, the maximum reaction velocity (Vmax) of AChE decreased, and the Michaelis constant (Km) remained the same.

CONCLUSIONMethomyl is a reversible non-competitive inhibitor of AChE. AChE of rat erythrocyte membrane is more sensitive to methomyl than that of human erythrocyte membrane; the cerebral cortical synapses have the most sensitive AChE to methomyl among synapses in various brain areas.

Acetylcholinesterase ; metabolism ; Animals ; Cerebellum ; drug effects ; Cerebral Cortex ; drug effects ; Erythrocyte Membrane ; drug effects ; enzymology ; Hippocampus ; drug effects ; Humans ; Inhibitory Concentration 50 ; Methomyl ; toxicity ; Rats ; Synapses ; drug effects ; Toxicity Tests

To assess the neurotoxic effects and redox responses of Aroclor 1254 (A1254) on perinatally exposed rat offspring, A1254 was administered by gavage from gestational day (GD) 6 to postnatal day (PND) 21. Neurobehavioral development, antioxidant enzyme activities, lipid peroxidation (LPO), nitric oxide (NO), and NO synthase (NOS) levels were analyzed in the offspring. Neurobehavioral development analysis revealed delayed appearance of the righting reflex, negative geotaxis, and cliff drop test responses in A1254 exposed group. Developmental A1254 exposure also caused oxidative stress in the brain of PND 22 offspring via reductions in the activity of SOD and GSH-Px, and by promoting a rise in the levels of NO and NOS.
Aging ; metabolism ; Animals ; Cerebral Cortex ; drug effects ; enzymology ; metabolism ; Chlorodiphenyl (54% Chlorine) ; toxicity ; Female ; Glutathione Peroxidase ; metabolism ; Kidney ; drug effects ; enzymology ; metabolism ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; enzymology ; metabolism ; Mice ; Nervous System ; drug effects ; growth & development ; metabolism ; physiopathology ; Nervous System Diseases ; chemically induced ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Oxidative Stress ; drug effects ; Pregnancy ; Prenatal Exposure Delayed Effects ; chemically induced ; Random Allocation ; Rats ; Superoxide Dismutase ; metabolism

OBJECTIVETo study the effects of 1-bromopropane (1-BP) on the functions of learning-memory and the central cholinergic system in rats.

METHODSForty male Wistar rats were randomly divided into four groups: low 1-BP group (200 mg/kg), middle 1-BP group (400 mg/kg), high 1-BP group (800 mg/kg) and control group, and the exposure time was 7 days. The Morris water maze (MWM) test was applied to evaluate the learning-memory function in rats. After the MWM test, the rats were sacrificed, the cerebral cortex and hippocampus were quickly dissected and homogenized in ice bath. The activity of acetylcholine esterase (AChE) and choline acetyltransferase (ChAT) in supernatant of homogenate were detected.

RESULTSThe latency and swim path-length of rats in middle and high 1-BP groups prolonged significantly in place navigation test and the efficiency of searching strategy obviously decreased, as compared with control group (P < 0.05 or P < 0.01). In spatial probe test, the number of crossing platform in three 1-BP groups decreased significantly, as compared with control group (P < 0.05 or P < 0.01). The cortical AChE activity of rats in middle and high 1-BP groups was significantly higher than that of control and low 1-BP group (P < 0.05 or P < 0.01). The AChE activity in rat hippocampus of high 1-BP group obviously increased, as compared with control group as compared with control group (P < 0.05). There was no significant difference of cortical ChAT activity between three 1-BP groups and control group (P > 0.05). In the hippocampus, there was no difference of ChAT activity among the groups (P > 0.05).

CONCLUSION1-BP exposure could significantly influence the learning-memory function in rats due to the increase of AChE activity.

Acetylcholinesterase ; metabolism ; Animals ; Cerebral Cortex ; drug effects ; enzymology ; Choline O-Acetyltransferase ; metabolism ; Hippocampus ; drug effects ; enzymology ; Hydrocarbons, Brominated ; toxicity ; Male ; Maze Learning ; drug effects ; Rats ; Rats, Wistar

OBJECTIVETo study the effect of chronic multiple stress on learning and memory, and the expression and activation of cerebral extracellular signal-regulated protein kinase (ERK) 1/2 of rats in vivo.

METHODSNinety male SD rats were divided randomly into control group and stress group. Rats in stress group were stressed everyday by one of the seven stressors including cold exposure, foot shock, white noise, restraint, tail hung up, sleep deprivation, and level shake, and then the ability of learning and memory was determined by Morris water maze test. Serum corticosterone (CORT) level was determined by radioimmunoassay kit. Western blot was performed to determine the expression and phosphorylation of ERK in hippocampus and prefrontal cortex of the brain.

RESULTSThe escape latencies of stressed rats were substantially longer than those of the controls in the water maze test (P < 0.01) except a transient recovery at the end of the third week after the stress. The stress also resulted in significantly higher serum CORT level and decreased P-ERK level in hippocampus and prefrontal cortex (PFC) (P < 0.01). Similarly, transient elevation of both CORT and P-ERK levels were observed at the end of the third week.

CONCLUSIONChronic multiple stress can lead to impaired learning and memory by decreasing the phosphorylation of ERK in the hippocampus and PFC. The partial recovery of learning and memory, CORT and P-ERK levels at the end of the third week may due to the adaptation of the rats to stressors.

Animals ; Cerebral Cortex ; enzymology ; physiopathology ; Corticosterone ; blood ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Hippocampus ; enzymology ; physiopathology ; Male ; Maze Learning ; physiology ; Memory Disorders ; enzymology ; etiology ; physiopathology ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Stress, Physiological

OBJECTIVETo investigate the effects of Erzhi Pill (二至丸,EZP) on nerve cell apoptosis in senescence model rats.

METHODSThe rats model of senescence was established by peritoneal D-galactose injection combined with thymusectomy. Forty SD rats were randomized into four groups, the normal control group, the senescence model group, the EZP treated group, and the vitamins treated group, 10 in each group. The rats were made into senescence model except those in the normal group. In the same time of D-galactose injection, the rats were treated respectively with distilled water, EZP 4.32 g/kg, and vitamins E and C 0.06 g/kg daily for 6 weeks via intragastric infusion. The index of main viscera (as brain, testis, etc.), serum levels of superoxide dismutase (SOD) activity, and total anti-oxidation capacity (T-AOC) were measured after a 6-week treatment. Meanwhile, the cerebral cortex neuronal apoptosis proportion and mitochondrial membrane potential (MMP) were detected by flow cytometry.

RESULTSBoth EZP and vitamins E and C treatments showed effects on increasing testis index and serum level of T-AOC, reducing the percentage of neuronal apoptosis in the cerebral cortex, and elevating MMP in the aging rats model.

CONCLUSIONSEZP could inhibit the cerebral cortex neuron apoptosis and maintain the mitochondrial function in the senescent process of rats induced by peritoneal D-galactose injection combined with thymusectomy. It also shows antioxidation effect to some extents.

Aging ; blood ; drug effects ; Animals ; Antioxidants ; metabolism ; Apoptosis ; drug effects ; Cerebral Cortex ; cytology ; Drugs, Chinese Herbal ; pharmacology ; Male ; Matrix Metalloproteinases ; metabolism ; Neurons ; cytology ; drug effects ; enzymology ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; blood

Cytoplasmic Cu/Zn superoxide dismutase (SOD1) is an antioxidant enzyme that converts superoxide to hydrogen peroxide in cells. Its spatial distribution matches that of superoxide production, allowing it to protect cells from oxidative stress. SOD1 deficiencies result in embryonic lethality and a wide range of pathologies in mice, but little is known about normal SOD1 protein expression in developing embryos. In this study, the expression pattern of SOD1 was investigated in post-implantation mouse embryos and extraembryonic tissues, including placenta, using Western blotting and immunohistochemical analyses. SOD1 was detected in embryos and extraembryonic tissues from embryonic day (ED) 8.5 to 18.5. The signal in embryos was observed at the lowest level on ED 9.5-11.5, and the highest level on ED 17.5-18.5, while levels remained constant in the surrounding extraembryonic tissues during all developmental stages examined. Immunohistochemical analysis of SOD1 expression on ED 13.5-18.5 revealed its ubiquitous distribution throughout developing organs. In particular, high levels of SOD1 expression were observed in the ependymal epithelium of the choroid plexus, ganglia, sensory cells of the olfactory and vestibulocochlear epithelia, blood cells and vessels, hepatocytes and hematopoietic cells of the liver, lymph nodes, osteogenic tissues, and skin. Thus, SOD1 is highly expressed at late stages of embryonic development in a cell- and tissue-specific manner, and can function as an important antioxidant enzyme during organogenesis in mouse embryos.
Animals ; Cerebral Cortex/embryology/enzymology ; Copulation ; Cytoplasm/*enzymology ; Embryonic Development/*physiology ; Female ; Immunohistochemistry ; Lung/embryology/enzymology ; Male ; Mice ; Mice, Inbred ICR ; Organogenesis/*physiology ; Pregnancy ; Stomach/embryology/enzymology ; Superoxide Dismutase/deficiency/genetics/*metabolism

BACKGROUNDFebrile seizure (FS) is the most common seizure disorders. Approximately one third of children with a febrile seizure have recurrent events. The mechanism of FS remains unclear. Heme oxygenase-1 (HO-1) is a member of the heat shock proteins family and can be induced in the brain by various stresses, including hyperthemia and seizure. This study aimed at investigating the changes of HO-1 in the cortex of rats after recurrent FS.

METHODSFS in rats was induced ten times, once every 2 days. In a bath of warm water, developing rats were randomly divided into two groups: control group (n = 16) and warm water-treated group (n = 50). The latter group was subdivided into hyperthermia group (n = 19) and FS group (n = 23). The expression and content of HO-1 mRNA in cortex were observed using in situ hybridization and quantitative reverse transcription-polymerase chain reaction (RT-PCR). The content of HO-1 protein in cortex was measured using Western blotting.

RESULTSHO-1 mRNA expression of cortex neurons in FS group was markedly increased in comparison with those in hyperthermia and control groups (P = 0.00), however, there was no statistic difference between hyperthermia group and control group (P = 0.16). The relative amount of HO-1 mRNA in cortex in FS group was increased by 53.13% and 96% in comparison with those in hyperthermia group and control group respectively (P = 0.00), but there was no obvious difference between the later two groups (P = 0.051). Western blotting analysis showed that the HO-1 protein content in cortex in FS group was increased by 198% and 246% in comparison with those in hyperthermia group and control group respectively (P = 0.00). There was no obvious difference in HO-1 protein content between the later two groups (P = 0.09).

CONCLUSIONSRecurrent FS in rats can cause the increase of HO-1 mRNA and protein in cortex which may be involved in the mechanism of FS. The short-time recurrent hyperthermia can not induce the increase of HO-1 mRNA and protein.

Animals ; Cerebral Cortex ; enzymology ; Fever ; enzymology ; Heme Oxygenase-1 ; analysis ; genetics ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Recurrence ; Seizures, Febrile ; enzymology

AIMTo design and synthesize novel AchE inhibitors.

METHODSThe condensation of 2-bromo-5, 6-dimethoxy-indan-1-one with various aminoalkyl phenols in the presence of K2CO3 and acetonitrile gave the corresponding title compounds, and the in vitro AchE and BchE inhibitory activities were evaluated by the modified Ellman method.

RESULTSSixteen novel target compounds 8a - p were synthesized, their structures were confirmed by 1H NMR, MS, IR and elemental analysis. Preliminary pharmacological test demonstrated that most of these compounds displayed high AchE inhibitory activities, the IC50 of the most potent inhibitor 8h was 50.0 nmol x L(-1), similar to that of Huperzine A (IC50 = 53.0 nmol x L(-1)), while all the compounds were almost inactive against BchE.

CONCLUSION2-Phenoxy-indan-1-one derivatives exhibit high activities of AchE inhibition and are worthy of further investigation.

Acetylcholinesterase ; metabolism ; Animals ; Cerebral Cortex ; enzymology ; Cholinesterase Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Drug Design ; Indans ; chemical synthesis ; chemistry ; pharmacology ; Inhibitory Concentration 50 ; Molecular Structure ; Rats ; Structure-Activity Relationship

OBJECTIVE: To observe the changes of adenylate cyclase(AC) on cerebral regions related to morphine dependence in rats and investigate the relationship between the enzymological changes and the mechanism of morphine dependence. METHODS: The technique of enzyme-histochemistry was used to detect the variations of AC of special seven cerebral regions including frontalis cortex, lenticula, corpus amygdaloideun, substantia nigra, hippocampus, periaqueductal gray and locus coerleus in morphine dependent rats. The enzymological changes were observed by optical microscope. Changes of gray degree of these cerebral regions were also observed by using the image analysis system. RESULTS: Compared with those in control group, the contents of AC in morphine dependent groups were increased. CONCLUSION The contents of AC are increase in those regions. The mechanism of morphine dependence close related to the increasing of AC. The correlation of the mechanism of morphine dependence and up-regulation of AC/cAMP-PKA system is discussed.
Adenylyl Cyclases/metabolism* ; Animals ; Brain/pathology* ; Cerebral Cortex/enzymology* ; Disease Models, Animal ; Female ; Hippocampus/enzymology* ; Male ; Morphine Dependence/pathology* ; Periaqueductal Gray/enzymology* ; Rats ; Rats, Sprague-Dawley ; Substance Withdrawal Syndrome/metabolism* ; Time Factors

Sandhoff disease is a rare autosomal recessive metabolic disease presenting bilateral optic atrophy and a cherry red spot in the macula. This case report presents the characteristics of a patient with Sandhoff disease as assessed by ophthalmic, neuroimaging, and laboratory procedures. Ophthalmologic examination revealed that the patient could not fixate her eyes on objects nor follow moving targets. A pale optic disc and a cherry red spot in the macula were seen in both eyes. Low signal intensity at the thalamus and high signal intensity at the cerebral white matter were noted in a T2-weighted brain MR image. A lysosomal enzyme assay using fibroblasts showed the marked reduction of both total beta-hexosaminidases, A and B. Based on the above clinical manifestations and laboratory findings, we diagnosed the patient as having Sandhoff disease.
Atrophy ; Cerebral Cortex/*pathology ; Child, Preschool ; Female ; Humans ; Isoenzymes/deficiency ; Lipid Metabolism, Inborn Errors/*diagnosis/enzymology ; Magnetic Resonance Imaging ; Ocular Motility Disorders/*diagnosis ; Optic Disk/*pathology ; Retinal Diseases/*diagnosis ; Sandhoff Disease/*diagnosis/enzymology ; Thalamus/pathology ; beta-N-Acetylhexosaminidase/deficiency