Altered expressions of SphK1 and S1PR2 in hippocampus of epileptic rats / 中国应用生理学杂志

OBJECTIVE@#To observe the expressions of sphingosine kinase 1 (SphK1) and sphingosine-1-phosphate receptor 2 (S1PR2) in hippocampus of epileptic rats and to investigate the pathogenesis of SphK1 and S1PR2 in epilepsy.@*METHODS@#One hundred and eight male Sprague-Dawley (SD) rats were randomly divided into control group (n=48) and pilocarpine (PILO) group (n=60). A robust convulsive status epilepticus (SE) was induced in PILO group rats by the application of pilocarpine. Control group rats were injected with respective of physiological saline. Pilocarpine group was randomly divided into 6 subgroups (n=8): acute group (E6 h, E1 d, E3 d), latent group (E7 d) and chronic group (E30 d, E56 d). Each subgroup has 8 control rats and 8 epileptic rats. Hippocampal tissue and brain slices were obtained from control rats and rats subjected to the Li-PILO model of epilepsy at 6 h, 1 d, 3 d,7 d,30 d and 56 d after status epilepticus (SE). Western blot technique was used to determine the expressions of SphK1 and S1PR2 in hippocampus at different point of time after pilocarpine treatment. Immunofluorescence was applied to detect the activation and proliferation of hippocampal astrocytes and the localization of SphK1 and S1PR2 in rat hippocampal astrocytes.@*RESULTS@#Compared with control group, the levels of SphK1 in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d) were significantly increased while the expressions of S1PR2 were decreased in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d)(P＜0.05 or P＜0.01). Immunofluorescence results showed astrocyte activation and proliferation in hippocampus of epileptic (E7 d) rats (P＜0.05). Confocal microscopy confirmed the preferential expressions of SphK1 and S1PR2 in epileptic rat(E7 d)hippocampal astrocytes.@*CONCLUSION@#The results indicate that SphK1 and S1PR2 may play an important role in the pathogenesis of epilepsy by regulating the activation and proliferation of hippocampal astrocytes and altering neuronal excitability.

Prelimilary experimental study of manganese enhanced-functional MR imaging on cat model about acute epilepsy caused by pentylenetetrazol / 中华放射学杂志

Objective To explore the activated brain region of acute epilepsy in cat model induced by pentylenetetrazol(FFZ)with manganese enhanced-functional MR imaging(ME-fMRI),and evaluate the application of ME-fMRI on localization of the activated brain.Methods Forty cats were divided into 4 groups by random number table method as epileptic A and B groups as well as control A and B groups. Cats of epileptic groups were injected with PTZ(55 mg/kg)intramuscularly,and those of control groups were injected with the saline at same dose.The behavior change in the epileptic and control group A was observed and electroencephalogram(EEG)was also undertaken.Cats of epileptic and control group B were performed ME-fMRI,and the percentage of the enhanced signal intensity was then calculated.Results After injection with PTZ(55 mg/kg)intramuscularly,epileptic seizure was all evoked,and then EEG recording showed spike-wave and polyspike-wave complexes.The neocortex of cats of epileptic group B was diffusely phanero-enhanced on ME-fMRI.The percent enhancement of signal intensity in cortex of frontal lobe,parietal lobe and occipital lobe was(34.6?5.7)% and that in cortex of temporal lobe with(22.9? 6.5)%,whereas those of control group B with(14.9?4.5)% and(11.6?3.2)% respectively.And there was significant difference between the above different localization of the brain in the two groups (t=-10.43,-5.46 respectively,P