Objective To investigate the effect of progesterone pretreatment of focal cerebral ischemic and reperfusion injury (fCIRI) and underlying molecular mechanisms.Methods A single intraperitoneal injection of progesterone (8 mg/kg) given 1 h,48 h and 96 h before fCIRI was established in male Sprague-Dawley rats.The number of survival of neurons in hippocampal CA1 region of the ischemiaside,as well as spatial memory function,was detected on days 3-8 after fCIRI.Extracellular-signalregulated kinase 1/2 phosphorylation (p-ERK1/2) and nuclear translocation of p-ERK1/2 in hippocampal CA1 region were examined using western blot.Results The number of survival of neuronal cells was significantly increased in ischemic groups treated with progesterone at 1 h and 48 h pre-fCIRI (164.3 ± 11.0,218.5 ± 9.1 and 142.7 ± 12.1,F =29.4,P ＜ 0.01) compared with fCIRI group treated with vehicle.Likewise,the escape-latency to reach the hidden-platform recorded in day 5 of Morris water maze test was reduced markedly in fCIRI-treatment groups compared with the vehicle group(10.3 ± 11.1,19.2 ±9.6 and 32.4 ± 14.3 ;F =35.8,P ＜0.01).The level of p-ERK1/2 was elevated notably during 24 h to 48 h postprogesterone by western blot,while restored to the baseline at 96 h post-progesterone.Improved nuclear translocation of p-ERK1/2 was observed from 2 h to 48 h post-progesterone.The progesterone receptor antagonist RU486 blocked the exaltation of either intracellular level or nuclear translocation of p-ERK1/2,which was induced by progesterone.Conclusions The pretreatment with progesterone exerts a neuroprotective effect against the ischemia-induced neuronal death and ameliorates the deficits in spatial memory through enhancing the activation of ERK1/2.The neuroprotection derived from pretreatment with progesterone achieves a time window of not less than 48 h,which is progesterone receptor-mediated ERK1/2 signaling pathway-dependent.

OBJECTIVETo investigate the underlying neuroprotective mechanisms of Tanshinone II A (TSA) on rat cerebral ischemia in vivo.

METHODStudy of TSA on rat cerebral ischemia in vivo: Male SD rats were divided into four groups (sham-operated, ischemic and treated group (lower dose and higher dose). Chronic cerebral ischemmia after permanent bilateral carotid artery ligation was introduced as an in vivo ischemic model. After ischemia impairment, TSA (2, 4 mg x kg(-1) x d(-1)) was administrated by ip for 30 days in treated group. We used Morris water maze to investigate the learning and memory. Levels of malondialdehyde (MDA), activity of superoxide dismetase (SOD) and glutathione peroxidase (GPX) in brain tissue were detected by spectrophotometer. High-performance liquid chromatography (HPLC) with fluorescence detection was applied to measure the contents of glutamate and gamma-aminobutyric acid (GABA) in cortex and hippocampus.

RESULTSTSA can improve learning and memory deficits in vascular dementia. An elevation of SOD and GPX activity and decrease of MDA level were shown in TSA treated group after brain ischemia. Decreased glutamate and gamma-aminobutyric acid induced by chronic brain ischemia were markedly inhibited by TSA pretreatment.

CONCLUSIONThe neuroprotective effect of TSA are partly due to its functions as follow: anti-free radical injury; regulating the content of glutamate and gamma-aminobutyric acid.

Animals ; Dementia, Vascular ; drug therapy ; metabolism ; physiopathology ; Disease Models, Animal ; Diterpenes, Abietane ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Male ; Malondialdehyde ; metabolism ; Maze Learning ; drug effects ; Memory ; drug effects ; Neuroprotective Agents ; administration & dosage ; Phenanthrenes ; administration & dosage ; Random Allocation ; Rats ; Rats, Sprague-Dawley

Objective To explore the safety and effectiveness of bridging therapy in elderly patients with acute stroke due to posterior circulation large vessel occlusion.Methods A total of 160 eld-erly patients with acute stroke caused by posterior circulation large vessel occlusion admitted to our department were prospectively recruited and randomly divided into bridging group(n=80)and control group(n=80).The bridging group received thrombolysis treatment and then mechan-ical thrombectomy.The control group received mechanical thrombectomy directly.Prognosis and adverse reactions were compared between the two groups.Results The NIHSS score and BATMAN score after treatment were significantly decreased in both groups(P＜0.01),and the two scores were obviously lower in the bridging group than the control group(6.54±1.23 vs 7.12± 0.98,2.12±0.34 vs 2.87±0.44,P＜0.01).There was no statistical difference in the conversion rate of bleeding after cerebral infarction between the two groups(5.00％vs 3.75％,P＞0.05).The number of intraoperative thrombus removal was significantly lower in the bridging group than the control group(2.43±0.33 vs 2.98±0.41,P＜0.01).Remarkable difference was observed in the mRS score between the two groups after treatment(P＜0.05),with the proportion of mRS score ranging from 0 to 1 larger in the bridging group than the control group(52.50％vs 27.50％,P＜0.05).Conclusion Bridging thrombolysis can significantly improve the neurological function in elderly patients with acute stroke due to posterior circulation occlusion.