盐酸戊乙奎醚对发育期大鼠学习记忆能力及海马c—Jun氨基末端激酶表达的影响

Effect of penehyclidine hydrochloride on learning - memory and expression of hippocampal c - Jun N -terminal kinase in developing rats

目的观察盐酸戊乙奎醚（Pen）对发育期大鼠学习记忆能力及海马c-Jun氨基末端激酶（JNK）表达的影响。方法无特定病原体（SPF）级健康sD大鼠40只，7日龄，按照随机数字表法分为两组，每组20只。Pen组大鼠经腹腔注射Pen注射液0．3mg／（kg·d），连续7d，生理盐水（NS）组大鼠经腹腔注射等量的Ns，连续7d。药物干预结束后各组随机处死10只大鼠，留取海马组织并测定湿／干重比（W／D）和总含水量（TCW），采用反转录．聚合酶链反应（RT—PCR）和Westernblot分别检测JNKmRNA及磷酸化JNK（p-JNK）蛋白表达，原位末端细胞凋亡检测（TUNEL）法检测海马组织细胞凋亡指数（AI）。两组余下大鼠于2月龄时行Morris水迷宫实验，随后处死大鼠，留取海马组织并测定其W／D和TCW，RT-PCR和Westernblot分别检测JNKmRNA及p-JNK蛋白表达，TUNEL法检测海马组织细胞AI。结果与NS组[（17．67±7．94）s、（12．35±6．78）s；（2122．67±543．56）mm、（I123．78±369．22）mm]比较，Pen组小鼠逃避潜伏期[（54．58±9．85）S、（56．73±7．85）S]及游泳距离[（4789．54±677．83）mm、（4987．34±884．85）mm]均延长（P〈0．05）。与同组大鼠14d龄时比较，Pen组大鼠2月龄时的W／D（4．94±0．77比3．43±0．51）、TCW（3．94±0．76比2．43±0．50）和AI[（35．15±5．97）％比（2．91±0．98）％]均升高（P〈0．05），海马组织JNKmRNA（0．97±0．17比0．45±0．10）及蛋白表达（2．78±0．75比1．08±0．25）均增加（P〈0．05）。与NS组比较，Pen组大鼠2月龄的W／D（4．94±0．77比3．36±0．45）、TCW（3．94±0．76比2．36±0．48）和AI[（35．15±5．97）％比（2．89±0．99）％]均升高（P〈0．05），海马组织JNKmRNA（0．97±0．17比0．44±0．09）及蛋白表达（2．78±0．75比1．03±0．28）均增加（P〈0．05）。结论Pen可能通过上调JNK表达及诱导海马组织细胞凋亡而对发育期大鼠学习记忆能力造成不利影响。

Objective To investigate the effect of penehyclidine hydrochloride on learning - mem- ory and expression of hippocampal c - Jun N - terminal kinase in developing rats. Methods Forty specific pathogen free （SPF） Sprague- Dawley （SD） rats, aged 7 days, were randomly allocated into two groups, 20 rats per group. Rats were injected intraperitoneally with penehyclidine hydrochloride at the dose of 0.3 mg,/（kg.d） or normal saline at the same dose for continuous seven days in Pen group or NS group. Af- ter drug administration, ten rats of each group were randomly euthanized and hippocampus was excised. The ratio of wet weight/dry weight （W/D） and total content of water （TCW） of hippocampus were tested. The expression of JNK mRNA and phosphorylated JNK （p -JNK） protein were detected respectively by re- verse transcription -polymerase chain reaction （RT- PCR） and Western blotting. Apoptosis index （AI） of hippocampus was determined by terminal dexynucleotidyl transferase （TdT） - mediated dUTP nick end labeling （TUNEL） method. The rest of rats underwent Morris water maze test when they were aged two months in the two groups. After Morris water maze test was finished, the rats were euthanized and hippo- campus was excised. W/D and TCW of hippocampus were tested. The expressions of JNK mRNA and p - JNK protein were detected by RT - PCR and Western blotting, respectively. AI of hippocampus was determined by TUNEL method. Results Compared to NS group [（17.67±7.94） s, （12.35±6.78） s; （2 122. 67± 543.56） mm, （1 123.78± 369. 22） mini, the escape latency [（54.58± 9. 85） s,（56. 73 ± 7. 85 ） s ] and swimming distance [ （ 4 789. 54 ± 677.83 ） ram, （ 4 987. 34 ± 884. 85 ）mm ] were prolonged （both P〈0. 05）. Compared to rats aged 14 d at the same group, AI[ （35, 15 ±5.97）% vs. （2. 91 ±0. 98）% ], W/D （4. 94 ±0. 77 vs. 3. 43 ±0. 51 ） and TCW （3. 94 ±0.76 vs. 2.43 ±0. 50） of hippoeampns were all notably higher （P 〈0. 05） and the expression of JNK mRNA （0. 97 ±0. 17 vs. 0, 45 ±0, 10） and p -INK protein （2.78 ±0. 75 vs. 1.08 ±0. 25） were significantly increased （ all P 〈 0. 05 ） in rats aged two months of Pen group. Compared to NS group, AI [ （ 35.15 ± 5.97） % vs. （2. 89 ± 0.99）%], W/D （4.94±0.77 vs. 3.36±0.45） and TCW （3.9 ±0.76 vs. 2.36±0.48） of hippo- campus were all notably higher （P 〈0.05） and the expression of JNR nRNA （0.97 ±0. 17 vs. 0.44 ± 0.09） andp-JNKprotein （2.78±0.75 vs. 1.03±0.28） were significatly increased （all P〈0.05） in rats aged two months of Pen group. Conclusion Penehyclidine hydrochlorale maybe cause adverse effect for learning and memory of developing rats by up - regulating the expression of JNK and inducing hipp- ocampal apoptosis.