Adrenocortical function in mice selectively bred for different sensitivity to ethanol

The adrenocortical response to ethanol, histamine and electric shock was studied in the Short-Sleep (SS) and Long-Sleep (LS) mice. The plasma corticosterone levels measured at 60 min following ethanol injection were consistently higher in LS mice (males and females) than in SS mice. The corticosterone levels determined 60 min after histamine injection (50 mg/kg) or electric foot shock were not statistically different in these two lines of mice. The initial rise of the corticosteroid after ethanol injection was identical in SS and LS mice, whereas the costicosteroid response to mild stress of saline injection was different: SS mice showed higher levels of corticosterone than LS mice at 20 and 30 min after the injection. Corticosterone increment attributable to alcohol stress clearly seemed greater in LS than in SS mice, even though the adrenals of the SS mice were 20–30% heavier than those of LS. The possible significance of these endocrine differences with respect to sensitivity to ethanol and behavioral arousal level was discussed.     

Augmentation of the antibody response in aged mice with an 8-derivatized guanosine nucleoside and its effect on immunological memory

The injection of aged mice with 7-methyl-8-oxoguanosine (7m8oGuo) along with aggregated human gamma-globulin (AHGG) results in an enhanced anti-HGG antibody response. Aged mice injected with AHGG alone make only a feeble anti-HGG response. The enhanced response in aged mice was not significantly different from the response obtained in young-adult mice injected only with AHGG. However, the enhanced response obtained by injection of 7m8oGuo in young-adult mice was several orders of magnitude greater than that observed in the aged mice. Aged mice given a primary injection of AHGG alone failed to make a secondary response to AHGG given 90 days later, whereas aged mice injected with 7m8oGuo along with a primary injection of AHGG showed variable secondary antibody responses to AHGG. Two of seven mice showed high degrees of immunological memory equivalent to that seen in young-adult mice while others showed either meagre or no responses. The effect of 7m8oGuo appeared to be primarily on B cells, albeit the role of T cells cannot be ruled out.     

Role of AT2 receptor in the brain in regulation of blood pressure and water intake

The effects of intracerebroventricular (ICV) injection of angiotensin II (ANG II) on blood pressure and water intake were examined with the use of ANG II receptor-deficient mice. ICV injection of ANG II increased systolic blood pressure in a dose-dependent manner in wild-type (WT) mice and ANG type 2 AT(2) receptor null (knockout) (AT(2)KO) mice; however, this increase was significantly greater in AT(2)KO mice than in WT mice. The pressor response to a central injection of ANG II in WT mice was inhibited by ICV preinjection of the selective AT(1) receptor blocker valsartan but exaggerated by the AT(2) receptor blocker PD-123319. ICV injection of ANG II also increased water intake. It was partly but significantly suppressed both in AT(2)KO and AT(1)aKO mice. Water intake in AT(2)/AT(1)aKO mice did not respond to ICV injection of ANG II. Both valsartan and PD-123319 partly inhibited water intake in WT mice. These results indicate an antagonistic action between central AT(1)a and AT(2) receptors in the regulation of blood pressure, but they act synergistically in the regulation of water intake induced by ANG II.     

小鼠睾丸注射不同转染试剂和注射方法对外源基因表达的影响

为探讨不同转染试剂(LipofectamineTM LTXPLUSTM、Lipofectamine2000和纳米化聚酰胺-胺型树枝状聚合物(PAMAM-D))和睾丸注射方法 (睾丸网注射、曲精细管注射和间质注射)对转基因小鼠生产效率的影响,将pEGFP-C1质粒分别与不同转染试剂混合后,按照不同的注射方法注入小鼠睾丸内,30 d后检测小鼠精子密度、活力、精子阳性率以及配种后仔鼠转基因阳性率。结果 3种转染试剂对小鼠繁殖性能影响由小到大依次为LipofectamineTM LTXPLUSTM、Lipofectamine 2000和PAMAM-D。转染后LipofectamineTM LTXPLUSTM、Lipofectamine 2000和PAMAM-D组精子的GFP阳性率分别为35.65%±0.69%、12.86%±0.35%和10.04%±0.20%。配种后仔鼠的PCR阳性率分别为29.17%、13.70%和5.88%。3种不同注射方法对小鼠睾丸都造成损伤,由小到大依次为睾丸网注射、曲精细管注射和睾丸间质注射,三者的阳性精子比例分别为35.13%±1.727%、15.13%±1.457%和0%,配种后仔鼠的PCR阳性率分别为33.3%、12.5%和0%。结果表明,LipofectamineTM LTXPLUSTM和睾丸网注射对小鼠睾丸的损伤最小,并能获得较高的转染效率。     

黄芪注射液对2型糖尿病动物模型KKAy小鼠脑微血管病变的影响

目的：观察黄芪注射液对2型糖尿病动物模型KKAy小鼠脑微血管病变的影响,探讨黄芪注射液对糖尿病脑血管病变的保护作用。方法：饲养至14周龄的雄性KKAy小鼠随机分成模型组和黄芪注射液治疗组（每日腹腔给药,剂量为3mL／kg）,同龄雄性C57BL／6J小鼠作为对照组。血糖仪测量20、24、28周龄时各组小鼠的空腹血糖水平。28周龄时处死各组小鼠,放射免疫法检测血清6-酮-前列腺素-F1α（6-Keto-PGF1α）和血栓素B2（TXB2）的含量。透射电子显微镜观察脑组织超微结构变化。结果：模型组KKAy小鼠从20周龄开始血糖水平明显高于正常组小鼠（P〈0．01）;黄芪治疗组小鼠从20周龄开始血糖水平明显高于正常组小鼠（P〈0．01）,但低于模型组小鼠（P〈0．05或P〈0．01）。模型组小鼠血清6-Keto—PGF1α水平较正常组降低（P〈0．01）,TXB2含量增高（P〈0．01）;与模型组相比,黄芪注射液治疗组小鼠6-Keto—PGF1α水平升高（P〈O．01）,TXB：含量下降（P〈0．01）。透射电镜显示模型组小鼠神经细胞胞核染色质疏松,线粒体肿胀,粗面内质网缩小,核糖体减少;治疗组小鼠以上病变明显改善。结论：黄芪注射液可以有效改善2型糖尿病动物模型KKAv小鼠脑微血管病变,保护神经细胞结构。     

Anesthetic effects of a three-drugs mixture —comparison of administrative routes and antagonistic effects of atipamezole in mice—

The anesthetic mixture of medetomidine (MED), midazolam (MID) and butorphanol (BUT) produced anesthetic duration of around 40 minutes (min) in ICR mice. We reported that this anesthetic mixture produced almost the same anesthetic effects in both male and female BALB/c and C57BL/6J strains. Intraperitoneal (IP) administration of drugs has been widely used in mice. However, various injectable routes of the anesthetic mixture may cause different anesthetic effects. First, we examined effects of the anesthetic mixture by subcutaneous (SC) and intravenous (IV) injection compared to IP injection. After injection of the anesthetic mixture, administration of atipamezole (ATI) induced mice recovery from anesthesia. Secondly, we examined how different dosage and optimum injection timing of ATI affected mice recovery from anesthesia. We used an anesthetic score to measure anesthetic duration and a pulse oximeter to monitor vital signs under anesthesia. Usually, drugs from SC injection work more weakly than IP or IV injection. However, we found no significant differences of anesthetic duration among the three different injection routes. Antagonistic effects of ATI (0.3 mg/kg and 1.5 mg/kg) worked equally when administered at 30 min after injection of the anesthetic mixture. Antagonistic effects of ATI (1.5 mg/kg) were stronger than ATI (0.3 mg/kg) at 10 min after injection of the anesthetic mixture. The anesthetic mixture is a useful drug to induce nearly the same anesthetic effects by different injection routes and has an antagonist of ATI which helps mice quickly recover from anesthesia. These results may contribute to the welfare of laboratory animals.     

Antigenic challenge of immunized mice induces endogeneous production of IL-3 that increases histamine synthesis in hematopoietic organs

Antigenic challenge of Nippostrongylus brasiliensis-infected mice induces a striking increase in histidine decarboxylase (HDC) activity in both spleen and bone marrow cells. This enhancement takes place within 1 h after injection, with a maximum at 4 h and a return to pretreatment values 20 h later. It is associated with the appearance of IL-3 in the sera of these mice. In addition, the intracellular histamine content in both hematopoietic organs is concomitantly increased. A similar injection of worm Ag into normal mice has no significant effect. Comparable enhancement of HDC activity and intracellular histamine content with almost identical kinetics is promoted by i.v. injection of rIL-3 into normal mice. Moreover, HDC levels in infected mice are increased to the same extent in response to either specific antigen or rIL-3 injection. Taken together these results support the conclusion that antigenic challenge of immunized mice induces endogeneous IL-3 which, in turn, promotes a rapid increase in histamine synthesis in hematopoietic organs.     

不同品系小鼠对代谢性高尿酸血症造模的影响

目的：分别以昆明种小鼠及ICR、C57BL/6J小鼠为研究对象,比较在复制高尿酸血症模型时可能的小鼠品系差异,并通过降尿酸药物别嘌呤醇与非布索坦验证选择降尿酸药物筛选时选用不同品系动物造模的影响。方法：采用不同剂量次黄嘌呤腹腔注射联用尿酸酶抑制剂氧嗪酸钾皮下注射给药,测定不同造模时段各品系小鼠血清尿酸值。结果：ICR、C57BL/6J小鼠对高尿酸血症造模耐受显著高于昆明种小鼠,在腹腔注射次黄嘌呤500mg/kg,皮下注射氧嗪酸钾300mg/kg时,才可获得稳定的可用于药物筛选的高尿酸血症模型。结论：选择高尿酸血症在体模型时,昆明种小鼠灵敏度高于ICR小鼠以及近交系的C57BL/6J小鼠。     

Effect of guanidinoethanesulfonic acid on brain monoamines in the mouse

Guanidinoethanesulfonic acid (GES) is known to induce convulsive seizures when administered intracisternally to rabbits and cats. The effects of GES on behavior, electroencephalographic recording and brain monoamine levels were examined in mice. When GES (900 nmol) was intraventricularly injected into mice, focal clonic movements of the face, vibrissae and ears together with twitching of the limbs were observed 0.5–1 min after the injection. Hypersensitivity was observed up to 7 min after the injection, after which the mice behaved normally. GES also induced sporadic spike discharges on electrocorticogram. The levels of 5-hydroxytryptamine (5-HT) of the GES-injected mice were lower than those of the saline-injected mice in the hippocampus, diencephalon, pons-medulla oblongata and cerebellum 5 min after the injection. No changes in the norepinephrine or dopamine levels were found after the GES injection. The level of 5-hydroxyindoleacetic acid increased in the striatum and cerebellum 5 min after the GES injection. These results suggest that GES-induced convulsive activities enhance the serotonergic neuroactivity in order to suppress the convulsions.     

诱导型一氧化氮合酶对内毒素休克小肠微循环的影响

采用静脉注射脂多糖(1ipopolysaccharide,LPS)的方法建立小鼠内毒素休克模型,探讨内毒素休克时小肠微循环的变化以及诱导型一氧化氮合酶(iNOS)对小肠微循环的影响。实验过程中连续监测小鼠平均动脉血压(mean afterial pressure,MAP)变化情况。利用FTTC标记红细胞和活体显微镜方法直接观察并计算小鼠小肠绒毛尖端小动脉和毛细血管内红细胞的流速和流量,并观察敲除小鼠iNOS基因和选择性iNOS抑制剂S-methylthiourea sulfate(SMT)对实验过程中小肠微循环的影响。结果显示,对于野生型小鼠,应用SMT处理和敲除iNOS基因对基线的MAP、小肠绒毛尖端小动脉和毛细血管的红细胞流速和流量没有显著性差别。给予LPS后,小鼠的MAP进行性下降。给予LPS前,应用SMT和敲除小鼠iNOS基因可以显著提高MAP：给予LPS后,小鼠小肠绒毛尖端小动脉和毛细血管内红细胞流速和流量显著下降。给予LPS前,应用SMT和敲除小鼠iNOS基因可以显著提高小肠绒毛尖端小动脉和毛细血管的红细胞流速和流量。结果表明,iNOS在内毒素休克小肠微循环衰竭的过程中发挥重要作用。一能性     

Synergistic anti-tumor effect of mini-cells prepared from Salmonella typhimurium with mitomycin C in EL4-bearing mice

Summary A statistically significant increase in survival time was observed in EL4-bearing mice after a mini-cell inoculation. However, no case of survival for over 30 days was observed after an EL4 graft in mice treated with mini-cells alone. Fifty percent of the mice survived for 40 days after an EL4 transplantation when the mice were treated with both an IV injection of mini-cells and an SC injection of mitomycin C. The mini-cell injection restored the macrophage chemotaxis activity in EL4-bearing mice but did not restore the lymphocyte activities.     

Comparative effects of recombinant acid sphingomyelinase administration by different routes in niemann-pick disease mice.

An inherited deficiency of acid sphingomyelinase (ASM) activity results in the Type A and B forms of Niemann-Pick disease (NPD). The aim of this study was to evaluate the effects of recombinant human ASM (rhASM) replacement therapy on the mouse model, by comparing different routes of administration. Eight NPD mice received rhASM via an intravenous injection (IV) administered at a dose of 1 mg/kg and another group of 8 NPD mice received the same dose by subcutaneous injection (SC). The plasma levels of ASM activity in intravenously administered mice were significantly elevated immediately after injection. In contrast, in the subcutaneously injected mice, the level of ASM activity was maximal 6 h after injection. The levels of ASM activity in both groups had declined substantially by 2 days after injection. It was concluded that rhASM administered by subcutaneous injection is completely absorbed, and offers a similar efficacy to intravenously administered recombinant enzyme.     

Rapid induction of thymic lymphomas by isopropyl methanesulfonate: a preliminary report

The direct-acting SN1 alkylating agent isopropyl methanesulfonate (IMS) was carcinogenic by subcutaneous injection in female Hsd:(ICR)BR mice, causing thymic lymphoid neoplasms within 7 months in at least 20 of 32 treated mice. No such neoplasms were observed in mice treated with the direct-acting SN2 methyl homolog, methyl methanesulfonate (MMS). Both the IMS-treated mice and the MMS-treated mice initially received 20 mumole of the respective compounds by sc injection once weekly; however, because of toxic effects the dose of IMS was reduced to 10 mumole per injection on the 63rd day and further reduced to 5 mumole per injection on the 120th day, after which this dose was maintained until the 202nd day when the last surviving IMS-treated mouse became moribund and was sacrificed. In 2 of the MMS-treated mice, 93% of which were alive at 288 days, tumors were observed at the site of injection, one being a papilloma and the other a subcutaneous sarcoma. IMS has not previously been implicated as a carcinogen, to our knowledge. Its induction of thymic lymphomas may conceivably be related to its ability to alkylate exocyclic oxygen atoms in the DNA of hemopoietic cells.     

IL-10 deficiency increases superoxide and endothelial dysfunction during inflammation

Little is known about the role of interleukin-10 (IL-10), an anti-inflammatory cytokine, in blood vessels. We used IL-10-deficient mice (IL-10 -/-) to examine the hypothesis that IL-10 protects endothelial function after lipopolysaccharide (LPS) treatment. The responses of carotid arteries were studied in vitro 6 h after injection of a relatively low dose of LPS (10 microgram ip). In IL-10 -/- mice, the maximum relaxation to ACh (3 microM) was 56 +/- 6% (means +/- SE) after LPS injection and 84 +/- 4% after vehicle injection (P < 0.05). Thus endothelium-dependent relaxation was impaired in carotid arteries from IL-10 -/- mice after LPS injection. In contrast, this dose of LPS did not alter relaxation to ACh in vessels from wild-type (IL-10 +/+) mice. Relaxation to nitroprusside and papaverine was similar in arteries from both IL-10 -/- and IL-10 +/+ mice after vehicle or LPS injection. Because inflammation is associated with increased levels of reactive oxygen species, we also tested the hypothesis that superoxide contributes to the impairment of endothelial function by LPS in the absence of IL-10. Results using confocal microscopy and hydroethidine indicated that levels of superoxide are elevated in carotid arteries from IL-10 -/- mice compared with IL-10 +/+ mice after LPS injection. The impaired relaxation of arteries from IL-10 -/- mice after LPS injection was restored to normal by polyethylene glycol-suspended superoxide dismutase (50 U/ml) or allopurinol (1 mM), an inhibitor of xanthine oxidase. These data provide direct evidence that IL-10 protects endothelial function after an acute inflammatory stimulus by limiting local increases in superoxide. The source of superoxide in this model may be xanthine oxidase.     

丙型肝炎病毒核酸疫苗的免疫效果观察

将丙型肝炎病毒Ｃ＋Ｅ１区基因克隆到不同的真核细胞表达载体ｐＣＤＮＡ３．１（＋）和ｐＳＶＬ中,通过肌肉注射和皮下注射免疫ＢＡＬＢ／Ｃ及Ｆ１小鼠后,产生了抗ＨＣＶ／Ｃ区抗体。其中核酸疫苗ｐｃＤＮＡ３．１－ＨＣＶ／Ｃ＋Ｅ１的免疫高峰的出现早于ｐＳＶＬ－ＨＣＶ／Ｃ＋Ｅ１,Ｆ１小鼠的抗体应答强于ＢＡＬＢ／小鼠。肌肉注射优于皮下注射。     

Copper metabolism in mottled mouse mutants: distribution of 64Cu in brindled (Mobr) mice.

1. Duodenal injection of 64Cu in treated adult mutant mice (Mobr/y) revealed severe malabsorption of copper. In suckling mutants, malabsorption was less severe, owing to delayed absorption between 2 and 5 h after injection. Pinocytosis at the distal small intestine seems the likely explanation for this difference, and this is supported by results of ileal injection of radioisotope in the suckling mice. 2. The distribution of 64 Cu in various organs was measured in suckling normal, mutant and heterozygote mice and in adult normal and mutant mice during 48 h after intracardiac injection. Excessive accumulation of radioisotope was observed in most extrahepatic organs of mutant and heterozygote mice and was most pronounced in kidney. This could not be explained by initial copper deficiency. The livers of suckling mutant and heterozygote mice lost radioisotope rapidly after normal initial uptake. This pattern was not seen in adult mutants.     

Effect of testosterone on the amount of serous-like granules in convoluted tubular cells of mouse submandibular glands.

The effect of testosterone on the amount of granules present in convoluted tubular cells of the submadibular glands of mice was studied by the following two methods; 1) an immunochemical method using antiserum specific to the granular components, and 2) a histographic method. The results obtained by these two methods were in agreement. The amounts of the granules in normal female and castrated male mice were one-tenth to one-twentieth of that in normal male mice. When male mice were castrated, the amount of granules decreased, reaching a minimum 20 days after the aperation the injection of the male hormone, testosterone, into castrated male mice caused an increase in the amount of granules; this increase reached a maximum 15 days after the injection. The increase of granules caused by testosterone injection was almost completely prevented by inhibitors of protein synthesis, actinomycin D and puromycin. This suggests that protein synthesis was indispensable to the increase in the amount of granules. In male mice, the injection of female hormones scarcely affected the amount of granules. Kinetic analysis of the decrease and increase of granules on castration and testosterone injection suggested that the male hormone stimulated granule synthesis, but it hardly influenced the loss of granules.     

A simplified intrathymic injection technique for mice

Intrathymic injection is a common technique used for research concerning immunotolerance induction, gene therapy and T cell development in mice. Traditionally used protocols involve major surgery that exposes the thoracic cavity, which results in injury to the mice and increased risk of poor recovery and postsurgical complications such as infection. We introduce a simplified intrathymic injection technique that does not expose the thoracic cavity and virtually eliminates pain, distress and postoperative complications while maintaining high injection efficiency. The technique is suitable for both adult and neonatal mice.     

Studies on adjuvants for human prophylactics. III. Comparison of adjuvanticity in different animal species.

Activities of common adjuvants were compared in mice, rabbits and monkeys with tetanus toxoid as an antigen. Aluminium gel showed consistently high adjuvanticity for antitoxin production in all animal species examined when administered subcutaneously. Water-in-oil in water (w/o/w) showed high activity comparable to that of aluminium in mice and rabbits but no activity in monkeys. Endotoxin was considerably effective in rabbits and monkeys but not so in mice. Production of both IgM and IgG antitoxin was promoted by the effective adjuvants in rabbits and monkeys. In mice, however, the effects of adjuvants on the production of IgM antitoxin was less significant and inconsistent. Contrary to the case of guinea pigs, tetanus antitoxin was produced in mice by ip injection to a level comparable to that induced by sc injection. The effects of adjuvants in mice administered by ip and sc injection were not significantly different from each other.     

A SERUM FACTOR INDUCING MONOCYTOSIS DURING AN ACUTE INFLAMMATORY REACTION CAUSED BY NEWBORN CALF SERUM

An intraperitoneal injection of newborn calf serum (NBCS) into CRF Swiss mice causes an inflammatory reaction characterized by an increase in the number of macrophages in the peritoneal cavity and a concomitant monocytosis. The serum of such mice contains a monocytosis-inducing factor, as demonstrated by the intravenous injection of serum collected 18 (CalS 18) and 24 hr (CalS24) after the intraperitoneal injection of NBCS. Serum from normal untreated mice, from mice given an intraperitoneal injection of sterile pyrogen-free saline, which does not cause an inflammatory reaction, or from mice 72 hr after an intraperitoneal injection of NBCS, when the inflammatory reaction has subsided, does not cause a monocytosis in test mice. Intravenous injection of CalS 18 causes not only a monocytosis but also an increase in the number of promonocytes and bone marrow monocytes, suggesting an increased production of monocytes. The effect of CalS 18, CalS24 and CalS 18 filtrate is specific for the mononuclear phagocytes, since only non-significant increases in the numbers of lymphocytes and granulocytes were observed. The active factor in CalS 18 was shown to be different from the monocytosis-inducing factor present in NBCS. The monocytosis-inducing factor in CalS 18 passes through an ultrafiltration membrane with an exclusion limit of 50,000 Daltons, so that the molecular weight must be below this value.