Research Of Effects Of Neuropeptide S On Methamphetamine-induced Neurotoxicity

Objective:1.Effect of NPS on METH-induced stereotyped behaviors.Effect of NPS on METH-induced regulation of glutamate release in striatum and hippocampus.2.Effect of METH on the level of endogenous NPS in the cerebrospinal fluid3.Effect of METH on the NPSR protein expression in striatum and hippocampusMethod:1.SD male rats were weighed,then recorded,and all of them were randomly divided into 4 different groups.The rats were pretreated with vehicle or NPS(10nmol per rat,i.c.v.).After 30min of pretreatment the subjects were treated with saline or METH(10 mg/kg,i.p.).Then the rats were placed in the test apparatus immediately and recorded their stereotyped behavior for 1 hour.Then glutamate and GABA concentration in the striatum and hippocampus were measured by HPLC.2.SD male rats were weighed,recorded and divided into two groups randomly.And the rats were treated with saline or METH(10 mg/kg,i.p.).One hour later the level of NPS in the cerebrospinal fluid was detected by ELISA.3.After 10 days of cell culture,the primary neurons of hippocampus and striatum were both randomly divided into 4 groups:control group,METH1?4 and 16 mnonoL.Morphological changes in the striatal and hippocampal neurons were observed ulder an inverted phase microscope 24 hours later.The NPSR expression of striatal and hippocampal neurons was measured by Western blot detection and Immunofluorescence.Result:1.Effect of NPS on METH-induced stereotyped behaviors.When compared to the saline administration after pretreatment with saline,we found an increase in the total number of stereotypies in the rats with METH administration afterpretreatment with saline.The increase of stereotype began at 10 min after METH administration,reached its peak at 25 min,and Femained the same for the rest of time.When compared to the METH adininistration after pretreatment with saline,the total number of stereotypies was not affected in the rats with METH administration after pretreatment with NPS.2.Effect of NPS on specific categories of METH-induced stereotype.In rats administered METH(10 mg/kg,i.p.),there was significant mam effect of NPS pretreatment on stereotyped circling(p<0.05),but no significant main effect of NPS pretreatment on stereotyped sniffing(p>0.05).The frequency of METH-induced stereotyped circling was decreased by NPS pretreatment respectively.3.Effect of NPS on METH-induced regulation of glutamate release in striatum and hippocampusWith METH admimhistration after pretreatment with saline,glutamate release was increased in striatum(p<0.01)and hippocampus(p<0.01),compared with the group with saline administration after pretreatment with saline.METH may increase the glutamate release in striatum and hippocampus.With METH administration after pretreatment with NPS,glutamate release was decreased in striatum(p<0.01)and hippocampus(p<0.05),compared with the group with METH administration after pretreatment with saline.NPS may restrain the increase of glutamate release induced by METH in striatum and hippocampus.4.Effect of NPS on METH-induced regulation of GABA release in striatum and hippocampusWith METH administration after pretreatment with saline,GABA release was not affected in striatum and hippocampus(p>0.05),compared with the group with saline administration after pretreatment with saline.METH may not affect GABA release in striatum and hippocampus.With METH administration after pretreatment with NPS,GABA release was not affected in striatum and hippocampns(p>0.05),compared with the group with METH administration after pretreatment with saline.5.Effect of METH on the level of endogenous NPS in the cerebrospinal fluidCompared with saline group,ELISA showed that there was no significant main effect of METH on the level of NPS in the cerebrospinal fluid(p>0.05).6.Effect of METH on morphological changes in striatum and hippocampusCompared with the control,primary striatal and hippocampal neurons demonstrated atrophy,neurites were broken,neural network architecture disappeared,cells fell off and floated significantly in 4 and 16 mmol/L groups.7.EfFect of METH on the NPSR protein expression in striatum and hippocampusWestern-blot showed that compared with control group,the NPSR expression of striatal neurons in 4 and 16 mmol/L groups was significantly decreased by Western blot detection(p<0.05).Compared with control group,the NPSR expression of hippocampal neurons in 4 and 16 mmol/L groups was significantly decreased by Western blot detection(p<0.01,p<0.05).8.Effect of METH on mean optical density of NPSR in striatum and hippocampusImmunofluorescence results showed that the mean optical density of NPSR protein in primary cultured striatal and hippocampal neurons of 4 and 16 mmol/L METH groups were significantly decreased compared with control group(P<0.01,P<0.05;P<0.01,P<0.05).ConclusionThe frequency of METH-induced stereotyped circling was decreased by NPS pretreatment respectively.NPS may restrain the increase of glutamate release induced by METH in striatum and hippocampus.There was no significant main effect of METH on the level of NPS in the cerebrospinal fluid.The NPSR protein expression in striatum and hippocampus was decreased under the effect of METH.