OBJECTIVETo observe the influence of lead exposure on the activity of nitric oxide synthase (NOS) in different brain regions of rat.

METHODSBy establishing a series of rat models exposed to different low levels of lead (drinking water containing 0.025%, 0.050%, 0.075% of lead acetate) during developing period, NOS activities in hippocampus, cerebellum, cerebral cortex and brain stem were studied.

RESULTSOn the 21st day after birth, NOS activities in hippocampus of three levels of lead exposed groups [(1.53 +/- 0.20), (1.66 +/- 0.23), (1.88 +/- 0.32) U/mg pro respectively], and in cerebellum [(0.87 +/- 0.24), (0.85 +/- 0.09), (0.91 +/- 0.18) U/mg pro respectively] were significantly lower than those of control group [(2.36 +/- 0.18), (1.41 +/- 0.18) U/mg pro, respectively, P < 0.01]. NOS activities in cerebral cortex of 0.075% group [at 7, 14, 21 d of age [(1.29 +/- 0.14), (1.03 +/- 0.15), (0.69 +/- 0.10) U/mg pro] were significantly lower than those in control group [(2.54 +/- 0.31), (1.64 +/- 0.22), (1.24 +/- 0.14) U/mg pro respectively], and 0.025% group [(2.42 +/- 0.19), (1.59 +/- 0.17), (1.27 +/- 0.12) U/mg pro respectively], and 0.050% group [(2.56 +/- 0.53), (1.77 +/- 0.19), (1.24 +/- 0.10) U/mg pro respectively, P < 0.05]. There were no significant differences among control, 0.025%, and 0.050% groups (P > 0.05). Lead exposure had no influence on NOS activity in brain stem at the same age (P > 0.05).

CONCLUSIONNOS activities in hippocampus, cerebellum and cerebral cortex were inhibited by low level lead exposure and the degree of the effect was related to Pb exposure time and/or level of Pb exposed.

Animals ; Brain ; drug effects ; enzymology ; Brain Stem ; drug effects ; enzymology ; Cerebellum ; drug effects ; enzymology ; Cerebral Cortex ; drug effects ; enzymology ; Dose-Response Relationship, Drug ; Female ; Hippocampus ; drug effects ; enzymology ; Lead ; toxicity ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVETo evaluate the effects of paroxetine on protein kinase PKA, PKC and CaMKII activities in different brain regions in a rat model of depression.

METHODSThirty-six adult male SD rats were randomized into 6 groups, including one control group (I) and 5 groups of depression model established by forcing the rats to swim for 4 weeks. The 5 depression groups received no treatment (II) or were treated with paroxetine at a single dose (III), for a week (IV), 2 weeks (V) or 4 weeks (VI). The radioactivity of PKA, PKC and CaMKII in the hippocampus and prefrontal cortex was quantitatively measured using a liquid scintillation counter.

RESULTSIn the rat hippocampus, PKA and CaMKII activities were significantly lower in groups II, III, IV, and V than in groups I and VI (P<0.01 or P<0.05), but comparable between groups VI and I (P>0.05). PKC activity was significantly lower in group II than in group I (P<0.01), but showed no significant difference between the paroxetine-treated groups and group I (P>0.05). In the prefrontal cortex, the activity of PKA in groups I, II, III, and IV was similar (P>0.05), but all significantly lower than that in groups V and VI (P<0.01). PKC activity was significantly higher in groups II and III than that in group I and other paroxetine-treated groups (P<0.01), and similar between groups IV and I (P>0.05); groups V and VI had significantly lower PKC activity than group I (P<0.01). Group I had the highest CaMKII activity among the groups (P<0.01).

CONCLUSIONChronic administration of paroxetine can reverse chronic stress-induced inhibition of PKA, PKC and CaMKII activity in rat hippocampus, while the effects of paroxetine on the protein kinases can be more complex in prefrontal cortex.

Animals ; Brain ; drug effects ; enzymology ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Depression ; enzymology ; Disease Models, Animal ; Hippocampus ; drug effects ; enzymology ; Male ; Paroxetine ; pharmacology ; Protein Kinase C ; metabolism ; Random Allocation ; Rats

BACKGROUNDAlzheimer disease (AD) is a neurodegenerative disease related to aging. At present, its pathological mechanisms remain unclear. Family members of the renin-angiotensin system (RAS) play a role in neuronal plasticity, as well as formation of learning and memory. In this study, we explore the effects of altered angiotensin-converting enzyme (ACE), and investigate the possible mechanisms of perindopril, an ACE inhibitor, on brain structure and function in a rat model of AD, as well as the role that ACE plays in AD.

METHODSSixty Sprague-Dawley rats were selected and randomly divided into 3 groups: control, AD, and perindopril. Each group consisted of 20 rats, with 10 rats for determining pathology, and the remaining 10 rats for quantifying ACE activity. The rat AD model was established by stereotactically injecting amyloid beta protein (A-beta) 1-42 into the right hippocampus. Learning and memory functions were tested using the Y-type electric maze. The number and morphology of abnormal neurons were determined by haematoxylin and eosin staining. Amyloid deposition was measured by Congo red staining. Finally, ACE activity was estimated by spectrophotometry.

RESULTSCompared with the control group, the number of times needed to escape electrical stimuli increased (23.70 +/- 3.13, P < 0.001), the number of normal neurons in the CA1 region was reduced (density of 96.5 +/- 32.6/mm, P < 0.001), amyloid deposition was obvious, and ACE activity increased ((34.4 +/- 6.6) nmol x g(-1) x min(-1), P < 0.001) in the AD group. In the perindopril group, the number of times needed to escape electrical stimuli decreased (18.50 +/- 3.66, P < 0.001), the number of abnormal neurons increased (density of CA1 neurons was 180.8 +/- 28.5/mm, P < 0.001), amyloid deposition was reduced, and ACE activity was down-regulated ((26.2 +/- 6.2) nmol x g(-1) x min(-1), P < 0.001).

CONCLUSIONSACE activity increased in the brains of AD rats. Perindopril improved learning and memory in AD rats, which correlated with decreased ACE activity and delayed AD pathogenesis.

Alzheimer Disease ; enzymology ; pathology ; physiopathology ; Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Brain ; drug effects ; enzymology ; pathology ; Disease Models, Animal ; Maze Learning ; drug effects ; physiology ; Neurons ; drug effects ; metabolism ; pathology ; Peptidyl-Dipeptidase A ; metabolism ; Perindopril ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore the effect of Bushen Huoxue Decoction (BHD) on the orphan receptor (Nurr1) and tyrosine hydroxylase (TH) in the brain of rats with Parkinson's disease (PD).

METHODSOne hundred and twenty SD rats were divided into 100 in the model group and 20 in the normal control group, fifty-eight SD rats from the model group, established into PD model successfully by injuring their substantia nigra (SSN) with 6-hydroxydopamine, were divided equally into the model group and the test group, and they were treated with saline and BHD, respectively, for eight successive weeks. The change in the rats' behavior before and after treatment was observed by counting the cycles of rotation induced by apomorphine injection; the pathology of neurons, level of Nurr1 mRNA expression, and amount of TH positive cells in SSN were observed after treatment.

RESULTSThe rats' behavior was improved in the tested group significantly, the rotation cycle after treatment being 84.0 ± 20.0 cycles/40 min, which was significantly lower than that in the model group (377.0 ± 62.3 cycles/40 min, P<0.01). Besides, the Nurr1 mRNA expression and TH positive cell in the test group were 0.97 ± 0.15 and 49.40 ± 14.72, respectively, which were significantly higher than those in the model group, 0.22 ± 0.03 and 5.45 ± 2.58, respectively (all P<0.01).

CONCLUSIONBHD could treat PD by enhancing the Nurr1 mRNA expression, increasing the TH content in brain, and promoting the repairing of injured neuron in cerebral SSN.

Animals ; Behavior, Animal ; drug effects ; Brain ; drug effects ; enzymology ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Gene Expression Regulation ; drug effects ; Neurons ; drug effects ; enzymology ; pathology ; Nuclear Receptor Subfamily 4, Group A, Member 2 ; genetics ; metabolism ; Parkinson Disease ; drug therapy ; enzymology ; pathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Substantia Nigra ; drug effects ; metabolism ; pathology ; Tyrosine 3-Monooxygenase ; metabolism

OBJECTIVETo study the effects of pyrethroids on the activity of gamma-aminobutyric acid transferase (GABAT) in rat brain.

METHODThe coupled enzyme ultraviolet spectrophotography was applied to observe the effects of deltamethrin (DM) and permethrin (PM) on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum in vitro and in vivo.

RESULTSIn vitro, DM and PM had no significant effects on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum at the final concentration of 10(-9) - 10(-4) mol/L. When 37.5 mg/kg DM and 600 mg/kg PM were orally administrated to the rats at one time, the activities of GABAT in rat cerebral cortex, hippocampus and cerebellum in the DM group [(2.96 +/- 0.43), (2.13 +/-0.44), (5.12 +/- 1.36) nmol x mg pro(-1) x min(-1), respectively] were lower than those in the control group [(3.43 +/- 0.41), (2.68 +/- 0.47), (6.74 +/- 1.64) nmol x mg pro(-1) x min(-1)] (P < 0.05), and the activities of GABAT in rat cerebral cortex and hippocampus in the PM group [(4.57 +/- 0.30), (4.18 +/- 0.63) nmol.mg pro(-1) x min(-1), respectively] were higher than those in the control group (P < 0.05). When 12.5 mg/kg DM and 200 mg/kg PM were orally administrated to the rats once a day for consecutive five days, the two pesticides had no significant effects on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum (P > 0.05).

CONCLUSIONSIn vitro, DM and PM had no significant effects on the activity of GABAT in rat brain; in vivo, DM and PM may have different effects on the activity of GABAT in rat brain, which deserve further study.

Animals ; Brain ; drug effects ; enzymology ; In Vitro Techniques ; Insecticides ; toxicity ; Male ; Pyrethrins ; toxicity ; Rats ; Spectrophotometry ; Transferases ; metabolism ; gamma-Aminobutyric Acid ; metabolism

The purpose of the present study was to investigate the effects of cornel iridoid glycoside (CIG) on the activity of cholinesterases in vitro, and to investigate the mechanism of CIG's treating Alzheimer's disease (AD). The sources of cholinesterases were prepared from human blood cells, rat brain homogenate and human blood plasma, respectively. The biochemical methods were used to detect the activity of acetylcholine esterase (AChE) and butyryl cholinesterase (BuChE) to investigate the influence of CIG on cholinesterases. The results showed that CIG inhibited the activity of AChE of human blood cells and rat brain homogenate, with the 50% inhibition rate (IC50) of 1.6 g . L-1 and 3.3 g . L-1, respectively; and the inhibition of AChE of CIG is reversible. CIG also inhibited the activity of BuChE of human blood plasma, with the IC50 of 2.9 g . L-1. In conclusion, CIG can inhibit the activity of AChE and BuChE in vitro, which may be one of the mechanisms of CIG to treat AD.
Acetylcholinesterase ; metabolism ; Animals ; Brain ; drug effects ; metabolism ; Cholinesterase Inhibitors ; pharmacology ; Cholinesterases ; metabolism ; Humans ; Iridoid Glycosides ; pharmacology ; Plasma ; enzymology ; Rats

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

AIM: To investigate the relationship between cerebroprotection of pinocembrin and epoxyeicosatrienoic acids (EETs) and their regulating enzyme soluble epoxide hydrolase (sEH). METHODS: Rats underwent middle cerebral artery occlusion (MCAO) to mimic permanent focal ischemia, and pinocembrin was administrated via tail vein injection at 10 min, 4 h, 8 h and 23 h after MCAO. After 24 MCAO, rats were re-anesthetized, and the blood and brain were harvested and analyzed. RESULTS: Pinocembrin displayed significant protective effects on MCAO rats indicated by reduced neurological deficits and infarct volume. Importantly, co-administration of 0.2 mg·kg(-1) 14, 15-EEZE, a putative selective EET antagonist, weakened the beneficial effects of pinocembrin. 14, 15-EET levels in the blood and brain of rats after 24 h MCAO were elevated in the presence of pinocembrin. In an assay for hydrolase activity, pinocembrin significantly lowered brain sEH activity of MCAO rats and inhibited recombinant human sEH activity in a concentration-dependent manner (IC50, 2.58 μmol·L(-1)). In addition, Western blot and immunohistochemistry analysis showed that pinocembrin at doses of 10 mg·kg(-1) and 30 mg·kg(-1) significantly down-regulated sEH protein in rat brain, especially the hippocampus CA1 region of MCAO rats. CONCLUSION Inhibiting sEH and then increasing the potency of EETs may be one of the mechanisms through which pinocembrin provides cerebral protection.
Animals ; Arachidonic Acids ; metabolism ; Brain ; drug effects ; enzymology ; metabolism ; Brain Ischemia ; drug therapy ; enzymology ; genetics ; metabolism ; prevention & control ; Disease Models, Animal ; Epoxide Hydrolases ; genetics ; metabolism ; Flavanones ; administration & dosage ; Humans ; Male ; Protective Agents ; administration & dosage ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the effects of Naoyikang (NYK) on expression of choline acetyltransferase (ChAT) in brain of rats with Alzheimer' s disease (AD).

METHODBilateral infusions of Ibotenic acid (IBO) into nucleus basalis of Meynert (NBM) using hamilton syringe and stereotaxic apparatus were adopted to establish the rat model of AD. After intragastrically administrated with different solution for 28 days, immunohistochemistry and Western-blot were adopted to study the expression of ChAT in frontal cortex of AD rats.

RESULTNYK could improve the morphology and increase the number of ChAT immunoreactive neurons, and significantly promote ChAT protein expression.

CONCLUSIONNYK may be able to increase the synthesis of acetylcholine (ACh) through elevating the expression of ChAT protein, thus improving the level of brain ACh so as to protect central cholinergic neurons.

Alzheimer Disease ; enzymology ; Animals ; Blotting, Western ; Brain ; drug effects ; enzymology ; Choline O-Acetyltransferase ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation ; drug effects ; Immunohistochemistry ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of deltamethrin on the filial brain nitric oxide synthase (NOS) activity and neurobehavioral development of the exposed lactational rats.

METHODSPregnant rats were randomizedly divided into the treated group and the control group. The treated group was administered orally with 3.35, 6.70 mg/kg deltamethrin every other day from postnatal day (PND) 1 to PND 19 while the control group was administered with the corn oil of same amount in the same period. The activity of NOS of filial brain and neurobehavioral functions of the filial rats were observed.

RESULTSThe lactational survival rate (81.80%:78.60%) in both treated groups was decreased significantly (P < 0.01) compared with that in the control group. The body weight of filial rats on PND 10, 21 in 6.70 mg/kg DM treated group [(16.62 +/- 2.2 8), (31.34 +/- 6.94) g] was less than those in the control group (P < 0.05). The delayed time in the filial rats in 6.70 mg/kg group was (3.05 +/- 1.20) s and the positive rates of passive escaping response in 3.35 and 6.70 mg/kg DM treated group were 22.5% and 21.5% respectively. There was the trend of the developmental increase of the activity of filial brain NOS between PND 5 and PND 21 and the NOS activity of rat brain on PND 5 in 6.70 mg/kg group [(0.60 +/- 0.07) U.mg pro(-1).h(-1)] was lower than that in the control group (P < 0.05).

CONCLUSIONExposure to high dose of deltamethrin in lactational female rats will decrease the activity of NOS of brain and retard the neurobehavioral development of their filial rats.

Animals ; Animals, Newborn ; Brain ; drug effects ; enzymology ; Female ; Learning ; drug effects ; Male ; Memory ; drug effects ; Nitric Oxide Synthase ; metabolism ; Nitriles ; toxicity ; Pregnancy ; Prenatal Exposure Delayed Effects ; Pyrethrins ; toxicity ; Rats ; Rats, Wistar