Effect of adrenalectomy and corticosterone replacement on prepulse inhibition and locomotor activity in mice

1 Stress is a risk factor in psychiatric illnesses such as schizophrenia. The aim of the present study was to investigate the effect of different circulating levels of the adrenal steroid corticosterone (CORT) on locomotor hyperactivity and prepulse inhibition of acoustic startle, two behavioural animal models of aspects of schizophrenia. 2 Male C57BL/6J mice (n = 10 per group) were anaesthetised with isoflurane and sham-operated or adrenalectomised (ADX). ADX mice were implanted with 50 mg pellets consisting of 100% cholesterol, or 2, 10 or 50 mg of CORT mixed with cholesterol. CORT pellet implantation dose dependently increased plasma CORT levels 3 weeks after surgery. Starting 1 week after surgery, mice were tested for prepulse inhibition after injection of saline or 5 mg kg(-1) of haloperidol. 3 In intact mice and in mice implanted with 10 mg of CORT, haloperidol treatment significantly increased prepulse inhibition (average values from 38 - 42 to 52%). Similar results were observed when testing the mice for amphetamine-induced locomotor hyperactivity (5 mg kg(-1)). In contrast, there was no significant effect of haloperidol in mice implanted either with cholesterol or 2 or 50 mg of CORT. 4 These results in behavioural animal models of schizophrenia suggest an important role of the stress hormone CORT in modulating dopaminergic activity in this illness.

用H-Y抗体在宫内处理植入前鼠胚对后代性比的影响

该文以C57BL/6J鼠分2组进行实验。实验组45鼠,对照组20鼠,与同品系雄鼠交配后,在3日龄胚期,通过腹部手术对实验组雌鼠每侧子宫腔内注入未稀释的H-Y抗血清与豚鼠补体(二者以1:2混合)3μl。抗血清是由C57BL/6L雌鼠用同品系雄鼠的脾细胞以2.5×10~(7)个/只的剂量,每周免疫一次,共免疫7次后制备。对照组的处理操作与实验组相同,但每侧子宫腔内仅注入补体3μl,未注入抗体。实验组中有42只产仔247只(每窝平均6只),雌雄比为2.7(180/67)雌性占73%;对照组20只均产仔共163只(每窝平均8只),雌雄比为0.92(78/85),雌性仔鼠占48%。

一种新的小鼠被毛突变基因定位

分别尝试用RAPD法和重组率测定法对所发现的被毛突变进行基因定位。结果为所选用的100个10bp RAPD引物中,87个获得了扩增产物,由于所获得的产物与小鼠表型间缺乏相关性,利用RAPD法未能将该基因定位到染色体上。以分布于小鼠11条染色体上的Idh1、Car2、Mup1、Pgm1、Hbb、Es10、Es1、Mod1、Gdc1、Ce2、Es3等生化基因位点为遗传标记,对分别与CBA/N和C57BL/6小鼠互交-回交所获得的F2代进行两点测试,结果表明该突变与Es3连锁,位于小鼠第11号染色体上。

Gene mapping of a new coat mutation in mouse

Gene mapping of a mouse coat mutation has been investigated. First, 100 10-bp random primers were used to amplify DNA, but the mutation could not be located by this method because there were no correlation between the amplified products and coat phenotypes. Second, by using Idh1, Car2, Mup1, Pgb1, Hbb, Es10, Es1, Mod1, Gdc1, Ce2, Es3 as genetic markers, linkage test crosses (two-point test) consisting of intercrossing uncovered BALB/c mice (homozygotes) to CBA/N and C57BL/6 mice with normal hair and backcrossing the heterozygotes of the F1 to the uncovered BALB/c mice were made. It was soon evident that the mutation was linked to Es3 on chromosome 11. Furthermore, three-point test was made by using Es3 and D11Mit8 (a microsatellite DNA) as genetic markers. The result showed that the mutation was linked to Es3 with the percentage recombination of (7.89 +/- 2.19)%, and linked to D11Mit8 with the percentage recombination of (26.38 +/- 3.57)%. The percentage recombination between Es3 and D11Mit8 was (32.90 +/- 3.81)%. The mutation was named Uncovered, with the symbol Uncv. According to the recombinations, the loci order was D11Mit8-26.30 +/- 3.57- Uncv-7.89 +/- 2.19-Es3. From the location on the chromosome, it was concluded that the mutation was a new mutation which affected the skin and hair structure of mouse. The Uncv has entered MGD (Mouse Genome Database).

~(12)C~(6+)离子辐照小鼠Lewis肿瘤的研究

研究了HIRFL提供的12C6+离子辐照C57BL/6J小鼠右后腿移植的Lewis肿瘤的生长延迟和碳离子辐照对Lewis肿瘤小鼠寿命的延长.结果表明,碳离子照射的小鼠肿瘤生长体积明显地小于对照的体积.在剂量相同、分次数辐照越多时,肿瘤生长就越缓慢,肿瘤抑制就越高.在辐照分次数相同时,不同剂量对受照肿瘤生长体积未产生差异.在4Gy×3,8Gy×3和12Gy×2组3种辐照剂量下,小鼠寿命的P值小于0.05;可知小鼠的寿命延长具有统计学意义.

富铬酵母对实验性糖尿病小鼠模型的治疗

目的：三价铬作为葡萄糖耐量因子的有效活性成分，具有改善糖尿病人的糖代谢和脂代谢的作用，因此补充三价铬是糖尿病治疗中的有效的营养措施，富铬酵母是目前向人体提供三价铬的有效途径，并且葡萄糖耐量因子可以提高靶组织对胰岛素的敏感性而不促进胰腺的胰岛素分泌，为治疗糖尿病提供了一种新方法。 方法：（1）取昆明种小鼠，分对照与实验组，适应性喂养后实验组小鼠按40mg/kg体重注射STZ，对照组注射相应体积柠檬酸缓冲液,连续注射5天，3天后测血糖值，取血糖值≥11.1mmol/L为成功模型。成模小鼠分为两组，一组灌胃富铬酵母悬液4周，另一组灌胃蒸馏水4周，测血糖值。（2）取昆明种小鼠，分对照与实验组，适应性喂养后实验组小鼠按200mg/kg体重注射STZ，对照组注射相应体积柠檬酸缓冲液，3d后测血糖，取血糖值≥11.1mmol/L为成功模型。成模小鼠分为两组，一组灌胃富铬酵母悬液4周，另一组灌胃蒸馏水4周，测血糖值。（3）取C57BL/6J断乳小鼠，随机分为正常饲料组和高脂饲料组，分别用相应饲料喂养3 周。高脂饲料组又分为高脂饲料对照组和高脂饲料实验组。第3 周末, 高脂饲料实验组腹腔内按100mg/kg体重一次性腹腔注射STZ；正常饲料组和高脂饲料对照组腹腔注射相应体积的无菌柠檬酸缓冲液。继续喂养4 周。小鼠以第7周末血糖为准，≥11.1mmol/L为成功模型。成模小鼠分为2组，1组每日灌胃富铬酵母悬液，另一组灌服相应体积的去离子水，4周后，测血糖值。 结果：对Ⅰ型糖尿病小鼠，富铬酵母治疗2周后，治疗组血糖明显低于对照组血糖（p<0.05），4周后显著低于(p<0.01)；对Ⅱ型糖尿病小鼠，富铬酵母治疗2周后，治疗组血糖明显低于对照组血糖（p<0.05），3周后显著低于(p<0.01)；对肥胖引起的Ⅱ型糖尿病小鼠，富铬酵母治疗2周后，治疗组血糖显 著低于对照组血糖(p<0.01)，且血清胰岛素浓度之间没有明显差异。 结论：富铬酵母具有明显的降血糖作用，且不刺激胰岛素分泌