Effect of baicalein on brain injury induced by 6-hydroxydopamine at different sites in rats / 中国药理学通报

Aim To explore the therapeutical effect and mechanism of baicalein on two 6-hydroxydopamine (6-OHDA ) induced Parkinson′s disease (PD ) rat models,which received unilateral lesions of the left medial forebrain bundle (MFB ) or caudate putamen (CPu ) made by stereotaxic injection of 6-OHDA (MFB-M,CPu-M).Methods PD rat models were established by microinjection of 6-OHDA into MFB or CPu.The anti-tremor effect of baicalein on PD rat models was examined.Spontaneous activity was recor-ded. Dopamine (DA ), dihydroxyphenylacetic acid (DOPAC)and homovanilic acid (HVA)in striatum were quantified by HPLC-ECD.The tyrosine hydroxy-lase (TH)and OX-42 positive cells were detected by immunohistochemical method.The morphological vari-ation of the neurons was confirmed by analysis at an ul-trastructural level.Results Baicalein significantly in-creased the spontaneous activity in CPu-M.The elec-tromyography (EMG ) recordings revealed that com-pared with 6-OHDA group,the tremor frequency in ba-icalein group was decreased by 55% in MFB-M,and by 60% in CPu-M.6-OHDA treatment decreased DA levels in the striatum,while treatment with baicalein attenuated the DA decreases in CPu-M.Moreover,ba-icalein treatment could increase TH-positive neurons and decrease OX-42-postive microglia compared with 6-OHDA group in both MFB-M and CPu-M.Conclu-sions In the present study,it is illustrated that ①microinjection of 6-OHDA into the MFB and the CPu could cause different pathological changes of PD, which is important for efficacy evaluation;②baicalein showed the ability to alleviate the behavior symptoms in PD-rats at different stages by improving motor function and attenuating muscle tremor;③therapeutic effect of baicalein was produced by inhibiting the inflammatory medium production and release,anti-apoptosis,chan-ging dopamine catabolism, and inhibiting dopamine turnover.

Interactions of Dopamine D1 and N-methyl-D-Aspartate Receptors are Required for Acute Cocaine-Evoked Nitric Oxide Efflux in the Dorsal Striatum

Alterations in nitric oxide (NO) release in response to psychostimulants in the striatum cause a plastic change contributing to the development and expression of addiction. In this study, regulation of NO efflux evoked by acute cocaine in the dorsal striatum was investigated using real-time detection of NO in vivo. We found that acute systemic injection of cocaine (20 mg/kg) increased NO efflux, which was reduced by the intrastriatal infusion of the dopamine D1 receptor antagonist, SCH23390 (7.5 nmol), and the dopamine D2 receptor agonist, quinpirole (5 nmol). Increased levels of NO efflux by acute cocaine were also reduced by the intrastriatal infusion of the N-methyl-D-aspartate (NMDA) receptor antagonists, MK801 (2 nmol) and AP5 (2 nmol). These findings suggest that interactions of dopamine D1 receptors and NMDA receptors after acute exposure to cocaine participate in the upregulation of NO efflux in the dorsal striatum.

Seizure Induced Alteration of Microtubule Associated Proteins Immunoreactivities in the Mongolian Gerbil Striatum / 대한해부학회지

The present study involves a chronological and comparative analysis of both microtubule-associated protein 1A (MAP1A) and microtubule-associated protein 2 (MAP2) immunoreactivities in the striatum of both seizure resistant (SR) and seizure sensitive (SS) gerbil. The MAP1A immunoreactivity is weakly detected in perikarya of SR gerbils. However, MAP1A immunoreactivity is more accumulated in perikarya and dendrites in the pre-seizure group. At 30 min postictal, MAP1A immunoreactivity in the perikarya is decreased. At 3 hr postictal, MAP1A immunoreactivity in perikarya and dendrites is similarly decreased to the level of SR gerbils. The MAP2 immunoreactivity is weakly detected in the perikarya and dendrites of SR gerbils. However, MAP2 immunoreactivity is more accumulated in perikarya and dendrites. In particular, the neuropil between unstained fiber tracts obviously contains strong MAP2 immunoreactivity. At 30 min postictal, MAP2 immunoreactivity isn't almost observed in striatum. At 3 hr postictal, the MAP2 immunoreactivity is not different in the 30 min post -seizure groups but is only observed in the neuropil. However, at 12 hr postictal, the decrease of both MAP1A and MAP2 immunoreactivities had recovered to the pre -seizure level of SS gerbils. These results suggest that MAPs immunoreactivity in the striatum is different in SR and SS gerbils, and that this difference may be the results of seizure activity in this animal.

ANALGESIC ACTION OF LITHIUM SALT IN RAT CAUDATE-PUTAMEN NUCLEUS / 重庆医科大学学报

Effect of lithium salt(Li)administnation to caudate-putamen nucleus (CPN) on pain response in the rat was studied by chronic cannula implantation and direct injection of drugs into the brain structurementioned above. The results were as follows:( 1 ) The injection of Li into anterior part of the head of CPN of rats produced significantly the analgesic effect that could be antagonized by naloxone, atropine,phento-lamine.propranolol, lysergic acid diethylamide and bicuculline, but not by haloperidol.(2) The injection of Li into central part of the head of CPN of rats did not produce analgesic effect.The results above showed that microinjection of Li into different parts of the head of CPN could give rise to different effects on pain response and the analgesic effect of Li could be related to metabolic changes of endogenous opioid peptides, acetylcholine, noradrenaline, gama aminobutyric acid and 5-hydroXytryptamin aad mediated by their receptors respectively

Effects of morphine dependence and withdrawl on SNAPs expression in different brain regions of rats / 中国药理学通报

Aim To investigate the effects of chronic morphine treatment and withdrawal on the level of SNAPs in different brain regions of rats,including nucleus accumbens(NAc),caudate putamen(CPu) and hippocampus(Hip).Methods Adult male Wistar rats were randomly assigned into control,morphine and spontaneous withdrawal group.The morphine dependent rat model was established by subcutaneous morphine injection with increasing doses for 8 d,three times a day(8:00,12:00,and 18:00).The control group was injected with the same volume of normal saline.Rats in morphine group were killed 4 h after the last injection,and rats in withdrawl group were killed at indicated time.Control groups were paralleled with all treatment groups.The brains were removed and the NAc,CPu and Hip were separated.The expression of SNAPs mRNA and protein were determined by RT-PCR and Western blot.Results The expression of ?SNAP in CPu of morphine dependent rats was up-regulated by about 25%(P