In order to explore the role of acetylcholine in the pathogenesis of Parkinson's disease (PD), the changes in the concentration of acetylcholine (Ach) in the striatum, the apoptosis of substantia nigra cells, the ultrastructure and the changes of Nissl cells in rats during the morbidity of PD, and the corresponding behaviors in rats with PD were observed. Rat PD model was established by using the modified Thomas method. Eighty-one rats were randomly divided into normal control, sham operation and PD groups and their behavior features were observed at post-operative day (POD) 7, 14 and 21 as three subgroups (n=9 each). The concentration of Ach in the striatum was determined by using high-performance liquid chromatography. The apoptosis of substantia nigra cells was assayed by using TUNEL method. The ultrastructural changes in the substantia nigra were observed under the electron microscopy, and the survival of neurons in the substantia nigra area was examined by using Nissl staining. In PD group at POD 7 to 21, the damage in the substantia nigra area was gradually aggravated, the concentration of Ach, apoptosis rate and turns of rotation were gradually increased, and the number of Nissl cells was gradually reduced over the time as compared with the normal control and sham operation groups (all P<0.05). It was concluded that there exist dynamic changes in Ach concentration, ethology and apoptosis of the substantia nigra cells during the morbidity of PD, suggesting the contribution of apoptosis to the morbidity of PD, and critical role of Ach in the pathogenesis of PD.
Acetylcholine ; pharmacology ; Animals ; Corpus Striatum ; drug effects ; metabolism ; pathology ; Disease Models, Animal ; Male ; Parkinson Disease ; metabolism ; pathology ; Rats ; Rats, Wistar

AIMTo determine the protective effect of ONO-1078, a leukotriene receptor antagonist, on focal cerebral ischemia induced by endothelin-1 in rats.

METHODSSlow microinjection of endothelin-1 (120 pmol in 6 microL, for > 6 min) into the region near the middle cerebral artery was used to induce focal cerebral ischemia. ONO-1078 (0.1 mg.kg-1) was i.p. injected 1 h before endothelin-1 injection. Neurological symptoms, brain edema, brain infarction size, and the survival neurons in cortex and striatum were observed 24 h after ischemia.

RESULTSIntracerebral microinjection of endothelin-1 induced remarkable neurological symptoms, brain infarction, brain edema, and decrease of survival neurons in the cortex and striatum. In rats pretreated with ONO-1078, endothelin-1-induced brain edema and brain infarction size were decreased. The numbers of survival neurons in striatum and cortex were increased significantly. The neurological symptoms were improved but not significantly.

CONCLUSIONONO-1078 possesses neuroprotective effect against cerebral ischemic injury induced by endothelin-1, therefore, leukotrienes may play a role in the injury of cerebral ischemia.

Animals ; Behavior, Animal ; drug effects ; Brain Edema ; pathology ; Brain Ischemia ; chemically induced ; pathology ; Cerebral Cortex ; pathology ; Cerebral Infarction ; pathology ; Chromones ; pharmacology ; Corpus Striatum ; pathology ; Endothelin-1 ; Leukotriene Antagonists ; pharmacology ; Male ; Neurons ; drug effects ; Neuroprotective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDParaquat (PQ; 1, 1'-dimethyl-4, 4'-bipyridinium), a widely used herbicide that is structurally similar to the known dopaminergic neurotoxicant MPTP (1-methyl-1, 2, 3, 6-tetrahydropyridine), has been suggested as a potential etiologic factor for the development of Parkinson's disease (PD). Aging is an accepted risk factor for idiopathic Parkinson's disease. The aim of this study was to test the hypothesis that paraquat could induce PD-like nigrostriatal dopaminergic degeneration in aging C57BL/6 mice.

METHODSSenile male C57BL/6 mice were intraperitoneally injected with either saline or PQ at 2-day intervals for a total of 10 doses. Locomotor activity and performance on the pole test were measured 7 days after the last injection and animals were sacrificed one day later. Level of dopamine (DA) and its metabolites levels in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD), and numbers of tyrosine hydroxylase (TH) positive neurons were estimated using immunohistochemistry.

RESULTSLocomotor activities were significantly decreased and the behavioral performance on the pole test were significantly impaired in the PQ treated group. Level of DA and its metabolites levels in the striatum were declined by 8 days after the last injection. Immunohistochemical analyses showed that PQ was associated with a reduction in numbers of tyrosine hydroxylase positive neurons.

CONCLUSIONSLong-term repeated exposes to PQ can selectively impair the nigrostriatal dopaminergic system of senile mice, suggesting that PQ could play an important role in the pathogenesis of Parkinson's disease (PD). Our results also validate a novel model of PD induced by exposure to a toxic environmental agent.

Aging ; pathology ; Animals ; Corpus Striatum ; drug effects ; Disease Models, Animal ; Dopamine ; analysis ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Motor Activity ; drug effects ; Paraquat ; toxicity ; Parkinson Disease, Secondary ; chemically induced ; Substantia Nigra ; drug effects ; enzymology ; Tyrosine 3-Monooxygenase ; analysis

The present study is to assess the prophylactic effect of quinacrine (QA) , an anti-malarial drug, against heatstroke in rats. Conscious rats were orally given equal volume normal saline or QA (dissolved in normal saline and final dosage for rats was 4.5, 9.0 and 18 mg x kg(-1)). An hour later rats were put into a warm water circulated hot chamber (41.0 +/- 0.5) degrees C. Rectal temperature (core temperature, T(co)) of rats in hot chamber was continuously monitored by a thermocouple. T(co) and survival time of rats showed that QA pre-treatment postponed the hyperthermia, and increased the survival time of rats in hot chamber. Primary striatum neurons' culture from new born rats was maintained with D-MEM and 10% FBS. After immuno-cytochemistry identification with antibodies against neural specific proteins, culture received 20 micromol x L(-1) QA only for 1 h and followed by 43.0 degrees C heat treatment for another hour, or 20 micromol x L(-1) QA for 1 h followed by 43.0 degrees C heat treatment for another hour. Control culture received heat treatment only. Cultures were labeled with the fluorescent indicator DPH and the relative membrane fluidity of neurons was measured with the help of fluorescent polarized spectrophotometer. [3H] Arachidonic acid (AA) labeled membrane of E. Coli cells was used as substrate to determine cPLA2 activity of neurons. Gas chromatography and mass spectrum were also employed to detect on the level of fatty acids level in rat striatum neurons. Results from cells indicated that inhibition of cPLA2, reduction the release of active fatty acids such as AA, and possibly, stabilization of the cell membrane which was disturbed by hot treatment, may contribute to the mechanism underlying heat protection and heatstroke preventive effects of quinacrine.
Animals ; Cells, Cultured ; Corpus Striatum ; drug effects ; pathology ; Fatty Acids ; metabolism ; Heat Stroke ; metabolism ; physiopathology ; prevention & control ; Hot Temperature ; adverse effects ; Male ; Membrane Fluidity ; drug effects ; Neurons ; enzymology ; metabolism ; physiology ; Phospholipases A2 ; metabolism ; Quinacrine ; pharmacology ; Rats ; Rats, Wistar

OBJECTIVETo investigate the protective effects of Huperzine A, a potent acetylcholinesterase inhibitor, against the hypoxic ischemic brain damage (HIBD) of the cognitive and morphology in the neonatal rats.

METHODSPostnatal 7 days old rats were given vehicle or Huperzine A (0.05 mg/kg or 0.1 mg/kg, i.p.) following HIBD (unilateral carotid artery ligation followed by hypoxia) or sham operation, and then tested the learning ability and memory in the Morris water maze (MWM) from 36 to 40 postnatal days. The performance in MWM (escape latency, probe time) were recorded to evaluate the learning and memory dysfunction. At the end of MWM trials, the rats were decapitated and their brains were histologically analyzed. The tissue loss in different brain regions including striatum, cortex, and hippocampus were analyzed by image analysis system. The CA(1) subfield neurons numbers were counted to evaluate the brain damage. The acetylcholinesterase histochemistry staining was used to determine the activity of acetylcholinesterase in different brain regions.

RESULTSCompared with sham-operated group, HIBD rats with the vehicle treatment displayed significant tissue losses in the hippocampus (including CA(1) neurons), cortex, and striatum, as well as severe spatial memory deficits (escape latency: 44 s vs 30 s, P < 0.05, probe time: 14 s vs 40 s, P < 0.01). Huperzine A treatment (0.1 mg/kg) resulted in significant protection against both HI-induced brain tissue losses and spatial memory impairments (mean escape latency: 34 s vs 44 s, P < 0.05, probe time: 35 s vs 14 s,P < 0.01). However, Huperzine A treatment (0.05 mg/kg) did not show any significant improvement of spatial memory impairments (mean escape latency: 45 s vs 44 s, P > 0.05, probe time: 17 s vs 14 s, P > 0.05), but moderate to severe brain tissue losses. There was a pronounced reduction of CA(1) neuron density in ipsilateral hemisphere of vehicle-treated group and 0.05 mg/kg Huperzine A group compared with contralateral hemisphere or ipsilateral hemisphere of sham-operated group and 0.1 mg/kg Huperzine A group (72 vs 232, P < 0.01, 72 vs 229, P < 0.01, respectively). There was a close linear correlation between the CA(1) neurons cell number and the mean escape latency for 5 d acquisition trials (r = 0.777, P < 0.01).

CONCLUSIONThe unilateral HI brain injury in a neonatal rat model was associated with cognitive deficits, and that Huperzine A treatment may be protective against both brain injury and spatial memory impairment. Huperzine A showed a therapeutic potential for the treatment of hypoxic-ischemic encephalopathy (HIE) caused by the perinatal asphyxia.

Acetylcholinesterase ; metabolism ; Alkaloids ; Animals ; Animals, Newborn ; Cerebral Cortex ; drug effects ; enzymology ; pathology ; Cognition Disorders ; drug therapy ; physiopathology ; Corpus Striatum ; drug effects ; enzymology ; pathology ; Female ; Hippocampus ; drug effects ; enzymology ; pathology ; Hypoxia-Ischemia, Brain ; drug therapy ; Male ; Maze Learning ; drug effects ; Neuroprotective Agents ; administration & dosage ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sesquiterpenes ; administration & dosage ; therapeutic use ; Treatment Outcome

A double toxin-double lesion strategy is well-known to generate a rat model of striatonigral degeneration (SND) such as multiple system atrophy-parkinsonian type. However, with this model it is difficult to distinguish SND from Parkinson's disease (PD). In this study, we propose a new rat model of SND, which is generated by simultaneous injection of 6-hydroxydopamine into the medial forebrain bundle and quinolinic acid into the striatum. Stepping tests performed 30 min after intraperitoneal L-dopa administration at 6 weeks post-surgery revealed an L-dopa response in the PD group but not the SND group. Apomorphine-induced rotation tests revealed no rotational bias in the SND group, which persisted for 2 months, but contralateral rotations in the PD group. MicroPET scans revealed glucose hypometabolism and dopamine transporter impairment on the lesioned striatum in the SND group. Tyrosine hydroxylase immunostaining in the SND group revealed that 74.7% of nigral cells on the lesioned side were lost after lesion surgery. These results suggest that the proposed simultaneous double toxin-double lesion method successfully created a rat model of SND that had behavioral outcomes, multitracer microPET evaluation, and histological aspects consistent with SND pathology. This model will be useful for future study of SND.
Animals ; Apomorphine/pharmacology ; Behavior, Animal/drug effects ; Corpus Striatum/drug effects/pathology ; Disease Models, Animal ; Dopamine Plasma Membrane Transport Proteins/metabolism ; Glucose/metabolism ; Injections, Intraperitoneal ; Levodopa/pharmacology ; Male ; Medial Forebrain Bundle/drug effects/pathology ; Oxidopamine/*toxicity ; Parkinson Disease/metabolism/pathology ; Positron-Emission Tomography ; Quinolinic Acid/*toxicity ; Rats ; Rats, Wistar ; Striatonigral Degeneration/*chemically induced/metabolism/pathology ; Touch/drug effects

PURPOSE: The purpose of this study was to determine the effect of dehydroepiandrosterone (DHEA) on recovery of muscle atrophy induced by Parkinson's disease. METHODS: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 20 microg) into the left striatum using stereotaxic surgery. Rats were divided into two groups; the Parkinson's disease group with vehicle treatment (Vehicle; n=12) or DHEA treatment group (DHEA; n=22). DHEA or vehicle was administrated intraperitoneally daily at a dose of 0.34 mmol/kg for 21 days. At 22-days after DHEA treatment, soleus, plantaris, and striatum were dissected. RESULTS: The DHEA group showed significant increase (p<.01) in the number of tyrosine hydroxylase (TH) positive neurons in the lesioned side substantia nigra compared to the vehicle group. Weights and Type I fiber cross-sectional areas of the contralateral soleus of the DHEA group were significantly greater than those of the vehicle group (p=.02, p=.00). Moreover, extracellular signal-regulated kinase (ERK) phosphorylation significantly decreased in the lesioned striatum, but was recovered with DHEA and also in the contralateral soleus muscle, Akt and ERK phosphorylation recovered significantly and the expression level of myosin heavy chain also recovered by DHEA treatment. CONCLUSION: Our results suggest that DHEA treatment recovers Parkinson's disease induced contralateral soleus muscle atrophy through Akt and ERK phosphorylation.
Animals ; Corpus Striatum/drug effects/metabolism ; Dehydroepiandrosterone/*pharmacology/therapeutic use ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Male ; Muscle Fibers, Slow-Twitch/drug effects ; Muscle, Skeletal/drug effects/metabolism ; Muscular Atrophy/drug therapy/*etiology/*pathology ; Myosins/metabolism ; Neurons/drug effects/enzymology ; Oxidopamine/toxicity ; Parkinson Disease, Secondary/*chemically induced/*complications ; Phosphorylation ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Rats, Sprague-Dawley ; Tyrosine 3-Monooxygenase/metabolism

OBJECTIVETo study the effects of intranigral injection of different doses of CuSO4.5H2O on dopaminergic neuron in the nigrostriatal system of rats.

METHODSWistar rats were divided into four groups, including control group, 10 nmol, 50 nmol and 200 nmol copper injected into left substantia nigra (SN) groups. Seven days after the intranigral injection of copper, dopamine (DA) contents in the striatum (Str) were measured by high performance lipid chromotophotography (HPLC); the density of tyrosine hydroxylase (TH) positive axons in the Str was measured by TH staining method; TH and Caspase-3 mRNA expression in the SN were measured by semi-quantitative RT-PCR. We detected the activity of superoxide dismutase (SOD) in the lesioned midbrain of rats using biochemical methods.

RESULTSDA and its metabolites contents had no significant difference between control group and low dose (10 nmol) copper group. But from 50 nmol copper group, DA contents in the lesioned sides were reduced with the increase in the copper doses injected, showing a significant linear correlation (F = 34.16, P < 0.01). In the 50 nmol copper group, TH positive axons in the Str decreased compared with those of the control and unlesioned sides (F = 121.9, P < 0.01). In the 50 nmol copper group, TH mRNA expression decreased (t = 3.12, P < 0.01) while Caspase-3 mRNA expression increased (t = 8.96, P < 0.01) in the SN compared with the control. SOD activity decreased in the midbrain of rats treated with 50 nmol copper compared with that of the control (t = 2.33, P < 0.01).

CONCLUSIONCopper could induce damage of dopaminergic neurons in the SN of rats through destroying antioxidant defenses and promoting apoptosis.

Animals ; Apoptosis ; drug effects ; physiology ; Axons ; drug effects ; metabolism ; pathology ; Caspase 3 ; drug effects ; genetics ; metabolism ; Copper ; toxicity ; Corpus Striatum ; drug effects ; metabolism ; pathology ; Dopamine ; metabolism ; Dose-Response Relationship, Drug ; Male ; Nerve Degeneration ; chemically induced ; metabolism ; pathology ; Neural Pathways ; drug effects ; metabolism ; pathology ; Neurons ; drug effects ; metabolism ; pathology ; Neurotoxins ; toxicity ; Oxidative Stress ; drug effects ; physiology ; Parkinsonian Disorders ; chemically induced ; metabolism ; physiopathology ; RNA, Messenger ; drug effects ; metabolism ; Rats ; Rats, Wistar ; Substantia Nigra ; drug effects ; metabolism ; pathology ; Superoxide Dismutase ; drug effects ; genetics ; metabolism ; Superoxide Dismutase-1 ; Tyrosine 3-Monooxygenase ; drug effects ; genetics ; metabolism ; Wallerian Degeneration ; chemically induced ; metabolism ; pathology

OBJECTIVETo observe the effects of tetramethylpyrazine (TMP) on brain oxidative damage induced by intracerebral perfusion of levodopa (L-DOPA) in rats with Parkinson's disease (PD).

METHODSPD model rats were induced by intracerebral injection of 6-hydroxyl dopamine (6-OHDA) and perfused in brain with L-DOPA using microdialysis technique. Changes in levels of 2,3-dihydroxy benzyl acid (2.3-DHBA) and 2,5-dihydroxy benzyl acid (2,5-DHBA) in striatum of rats, formed by extracellular hydroxyl radical from salicylic acid capturing, were dynamically observed at various time points by HPLC-ED.

RESULTSAfter treatment with L-DOPA, 2,3-DHBA and 2,5-DHBA in the model group showed significantly higher levels at 6 and 7 time points as compared with those in the sham-operated group at the corresponding time points (P <0.05 or P< 0.01), while these abnormal elevations were significantly inhibited in the TMP treated groups, either in large or small dose (P<0.05 or P<0.01).

CONCLUSIONTMP could reduce the L-DOPA induced brain oxidative damage in PD rats.

Animals ; Anti-Inflammatory Agents, Non-Steroidal ; therapeutic use ; Catechols ; metabolism ; Chromatography, High Pressure Liquid ; methods ; Corpus Striatum ; drug effects ; metabolism ; pathology ; Hydroxybenzoates ; Levodopa ; administration & dosage ; Male ; Microdialysis ; Oxidative Stress ; drug effects ; Oxidopamine ; Parkinson Disease, Secondary ; chemically induced ; drug therapy ; metabolism ; Pyrazines ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley

The aim of this study is to investigate the protective effect of N-[2-(4-hydroxyphenyl)ethyl]-2-(2, 5-dimethoxyphenyl)-3-(3-methoxy-4-hydroxyphenyl)acrylamide (FLZ), a novel synthetic squamosamide cyclic derivative, against Parkinson's disease (PD) model mice induced by the inflammatory bacterial endotoxin, lipopolysaccharides (LPS) and the neurotoxin 1-methy-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). C57/BL mice were ip injected LPS (5 mg x kg(-1)) once. One week following the LPS injection, mice received a subcutaneous injection of MPTP (25 mg x kg(-1)) once daily for 2 days. Eight weeks later, FLZ (25, 50 and 75 mg x kg(-1)) was orally administered to mice once daily for 60 days. The motor ability of the mice was evaluated by rod climbing test and footprint test. The dopamine (DA) levels in mouse striatum were determined by high performance liquid chromatography system. The tyrosine hydroxylase (TH)-positive cells were showed by immunohistochemical analysis. FLZ treatment significantly improved motor dysfunction of mice challenged by LPS plus MPTP. The increase of TH-positive cell numbers and elevation of DA levels may be contributed to the beneficial effects of FLZ on motor behavior. This study showed FLZ has significant therapeutic effect on LPS plus MPTP induced chronic PD model, which indicates its potential as a new candidate drug to treat PD.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; 3,4-Dihydroxyphenylacetic Acid ; metabolism ; Acrylamides ; pharmacology ; Animals ; Caffeic Acids ; pharmacology ; Corpus Striatum ; metabolism ; Dopamine ; metabolism ; Homovanillic Acid ; metabolism ; Lipopolysaccharides ; Male ; Mice ; Mice, Inbred C57BL ; Motor Activity ; drug effects ; Neurons ; drug effects ; metabolism ; Parkinson Disease, Secondary ; chemically induced ; metabolism ; pathology ; physiopathology ; Random Allocation ; Tyrosine 3-Monooxygenase ; metabolism