硕鼠不是大老鼠

中学课本对《诗经·硕鼠》中＂硕鼠＂的解释是大老鼠,但这种说法很可能是错误的。因为如果是大老鼠,那么＂硕鼠硕鼠,无食我苗＂就解释不通,因为老鼠是不吃植物根茎和幼苗的,而＂三岁贯女＂（养了你三年）也显得很突兀。

大老鼠和小老鼠

“啊。再好也没有的消息，你听见别人说吗？”老老鼠跑进来对大老鼠说道，“你要知道啊，狮子把猫逮住了，我们大家都可以跑来跑去玩儿了。”

狮猫与大老鼠

一双贼溜溜的圆眼睛，一个胖鼓鼓的犬肚子，二条粗粗的长尾巴。这是什么？哎呀，这是一只和猫差不多大的胖老鼠。这么大的老鼠，胃口也一定很大吧？

Recombinant adeno-associated virus carrying thymosin β4 suppresses experimental colitis in mice

AIMTo investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β4 (AAV-Tβ4) on murine colitis via intracolonic administration.METHODSAAV-Tβ4 was prepared and intracolonically used to mediate the secretory expression of Tβ4 in mouse colons. Dextran sulfate sodium (DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to establish a mouse colitis model resembling Crohn’s disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ4 on colitis. The activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis and proliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTSRecombinant AAVs efficiently delivered LacZ and Tβ4 into the colonic tissues of the mice, and AAV-Tβ4 led to a strong expression of Tβ4 in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ4-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ4 significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ4 also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSIONTβ4 exerts a protective effect on murine colitis, indicating that AAV-Tβ4 could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.

High-Performance Liquid Chromatographic Method for Determination of Germacrone in Rat Plasma

Aim A reliable high-performance liquid chromatographic (HPLC) method wasdeveloped for determination of germacrone in rat plasma. Methods The plasma samples were treatedwith acetonitrile and analyzed by HPLC with UV detection at 244 nm. Results The limit of detectionwas 100 ng·mL^(-1) for germacrone in plasma and the linear range was 0.1004-15.06 μg·mL^(-1) inplasma. The RSD of intra-day and inter-day assay was 1.87% - 4.29% and 1.29% -5.15%, respectively.The recoveries of germacrone were over 95%. The endogenous substances in plasma did not show anyinterference in the analysis. Conclusion The method is accurate and convenient, and suitable forpharmacokinetic studies of germacrone in rats.

Comparative study on glutathione transferases of rat brain and testis under the stress of phenobarbitol and β-methylcholanthrene

A comparative study was made on the tissue specific expression of glutathione transferases (GST) in brain and testis after exposure of rat to phenobarbitol (PB) and β-methylcholanthrene (MC). Glutathione transferases, a family of multifunctional proteins are involved in intracellular transport processes and in detoxication of electrophilic xenobiotics by catalyzing reactions such as conjugation, isomerization, reduction and thiolysis. On purification, the yield of GST proteins by affinity chromatography was 39% in testis and 32% in brain. The affinity purified testis GSTs were resolved by chromatofocusing into six anionic and four cationic isozymes, and in brain glutathione transferases were resolved into four anionic and three cationic isozymes, suggesting the presence of multiple isozymes with Yc, Yb, Yβ and Yδ in both of them. In testis and brain, these isozymes at identical pI values showed variable functions with a battery of substrates and the cationic isozymes of brain and testis showed identical properties in CHP (cumene hydroperoxide) at pH values of above 7.0. Substrate specificity studies and immunoblot analysis of testis and brain proteins revealed that they play a predominant role in the detoxication of phenobarbitol or β-methylcholanthrene. Expression of the isozymes in testis and brain on exposure to PB and MC indicated elevated subunit variation. In both testis and brain, Yδ of π class was expressed on PB treatment and Yc of α class and Yβ of μ class was expressed in MC treated testis and only Yc was predominantly expressed in MC treated brain. Thus these subunits expression is considered as markers for carcinogenesis and specific to chemical toxicity under phenobarbitol and β-methylcholanthrene stress.

EFFECT OF ELECTROACUPUNCTURE OF DUMAI-ACUPOINTS ON CEREBRAL NO AND BLOOD ENDOTHELIN CONTENTS IN RATS WITH ACUTE CEREBRAL ISCHEMIA

Thirty Wistar rats were randomly and evenly divided into control group, cerebral ischemia group and ischemia + electroacupuncture (EA) group. The bilateral common carotid arteries were occluded to induce acute cerebral ischemia. Nitric oxide (NO) and endothelin (ET)contents in the cerebral tissues and blood were measured under normal condition, immediately after ischemia and following EA. Results showed that after acute cerebral ischemia NO and ET contents in the cerebral tissues increased significantly (P<0.01) while serum ET increased and serum NO lowered obviously (P<0.05). Following EA of Baihui (GV 20) and Dazhui (GV 14), both NO and ET in cerebral tissues and serum turned to normal basically. It showed that EA could protect the cerebral tissues from injury induced by ischemia, NO and ET might participate in the modulation process of EA.

EFFECT OF ELECTROACUPUNCTURE ON SYNAPTIC PLASTICITY OF HIPPOCAMPAL NEURONS IN CEREBRAL ISCHEMIA RATS

Objective: To observe the effect of electroacupuncture (EA) on synaptic structure of hippocampal nerve felts and synaptophysin(SYN)expression in rats with cerebral ischemic injury. Methods: Sixty Wistar rats were randomized into sham-operation group, cerebral ischemia (CI) group and EA group, each of which was further divided into 1week (W) and 5W subgroups. CI injury model was established by occlusion of the bilateral common carotid arteries. 'Baihui'(百会 GV 20), 'Dazhui' (大椎 GV 14), 'Renzhong'(人中 GV 26) and 'Guangyuan'(关会 CV 4) were punctured and stimulated electrically. The brain tissue sections containing hippocampus region were stained with immu nohistochemical technique and observed under light microscope and transmission electronic microscope. Results: After CI, the ischemic injury as degeneration of the presynapse compositions, decrease of the synaptic numeral density, and low expression of SYN were observed in hippocampal CA1 area. By the 5th week after CI, the neonatal synapses of Cl and EA groups appeared, and SYN expression was upregulated. In EA group, the recovery of the numeral density of synapses was especially noticeable, being 93.8% of that of sham-operation group and significantly higher than that in Cl group (P<0.01). Compared with sham-operation group, the calibrated optical density (COD) values of SYN increased to 70% in CI group, and 93.3% in EA group, and COD value in EA group was significantly higher than that in Cl group (P<0.01). Conclusion: EA can function in promoting synaptic regeneration and enhancing and perfecting the actions of the reconstructed synapses in hippocampal CA1 area in Cl rats.

EFFECT OF ELECTROACUPUNCTURE OF SCALP-POINTS ON ABNORMAL DISCHARGES OF NEURONS AROUND THE CEREBRAL HEMORRHAGE FOCUS IN THE RAT

Objective: To study the mechanism of electroacupuncture (EA) of scalp-points for regulating abnormal discharges of neurons in different regions around the cerebral hemorrhage focus by using neuro-electrophysiological methods. Methods: 80 Wistar rats (anesthetized with 20% urethane 1 g/kg, i.p.) were randomly divided into normal, saline, model and EA groups, with 20 cases in each group. Cerebral hemorrhage model was established by intracerebral injection of the rat’s own arterial blood sample (40 uL). In rats of saline group, the same volume of saline was given for intracerebral injection. Extracellular electrical activity of neurons of the caudate nucleus and parafascicular nucleus and Tail flicking latency (TFL) were used as the indexes. “Baihui”(百会 GV 20) and “Taiyang”(太阳 EX-HN 5) were punctured from GV 20 towards EX-HN 5 with filiform needles and stimulated electrically with stimulating parameters of strength of 1 V, frequency of 15 Hz and duration of 15 min. Results: Compared with normal group, TFL values of model group and EA group increased significantly (P<0.01); and compared with model group, those of EA group decreased significantly (P<0.01), suggesting that the pain threshold increased significantly in cerebral hemorrhage rats while after acupuncture stimulation, it lowered strikingly. Compared with normal and saline groups, the latency values of the pain excitement and inhibitory responses of the cellular discharges of the caudate and parafascicular nuclei in model and EA groups increased significantly (P<0.05～0.01), while after EA, it recovered apparently (P<0.01), showing an apparent regulative effect of EA on the abnormal changes of discharges of neurons around the cerebral hemorrhage focus. Conclusion: Scalp-acupuncture possesses an apparent regulatory effect on the abnormal electrical activity of neurons around the cerebral hemorrhage focus which may favor the early recovery of functional activity of neurons near the focus tissues.

STUDY ON INVOLVEMENT OF L-ARG-NO IN THE PROTECTIVE ACTION OF ELECTROACUPUNCTURE ON CEREBRAL ISCHEMIC INJURY IN THE RAT

In the present study, the involvement of L-arginine(L-Arg) NO on the protective action of electroacupuncture(EA) on cerebral ischemic injury was observed in acute ischemia-reperfusion(IR) rat model by taking regional cerebral blood flow(r-CBF),cerebral water content(CWC),and blood nitric oxide(NO) contents as indexes. Results showed that 1) EA could cause r-CBF and serum NO content to increase and CWC to lower, suggesting an protective action of EA on IR cerebral injury; 2) intravenous injection of L-Arg also had an protective effect on cerebral IR cerebral injury, while L-NNA had no this effect; and 3) pre-treatment with L-Arg might strengthen the effect of EA further, while pretreatment with L-NNA could weaken its effect. It indicates that L-Arg-NO may be involved in the effect of EA in protecting the brain from ischemic injury.

EFFECT OF ELECTROACUPUNCTURE ON NOREPINEPHRINE LEVEL AND APOPTOSIS IN CEREBRAL CORTEX TISSUE IN RATS WITH CEREBRAL ISCHEMIA-REPERFUSION

Objective: To investigate the underlying neurobiological mechanism of the protective effect of electroacupuncture (EA) during cerebral ischemia-reperfusion (CI-R). Methods: In the first part of the study, 15 SD rats were evenly randomized into control group, CI-R-48h model group and CI-R-48h+EA group. The cortical apoptosis and expression of Bcl-2 and Bax proteins in each group were detected by flow cytometer (FCM). In the second part of the study, 75 SD rats were evenly randomized into control, CI-R-3min, CI-R-3min+EA, CI-R-48h and CI-R-48h+EA groups. Cortical norepinephrine (NE) concentration was detected by fluorescence spectrometer. CI-R model was established by occlusion of the bilateral common carotid arteries and reperfusion. EA (4～16 Hz, 1～3 V) was applied to “Shuigou”(水沟 GV 26) and “Chengjiang”(承浆 CV 24) for 30 min before CI and after reperfusion respectively. Results: In the first part of this study, results indicated that the number of the apoptotic neurons and the apoptosis rate of CI-R-48h group were significantly higher than those of control group; while comparison between CI-R-48h+EA and CI-R-48h groups showed that the number of the apoptotic neurons and the apoptosis rate of the former group were significantly lower than those of the later group (P<0.05). In comparison with control group, after CI-48h, Bax expression was up-regulated significantly and Bcl-2 down-regulated markedly (P<0.05). Comparison between CI-R-48h and CI-R-48h+EA group indicated that Bax expression of the later group was significantly lower than that of the former group, while Bcl-2 expression of CI-R-48h+EA group was significantly higher than that of CI-R-48h group (P<0.05), suggesting that EA could reverse CI induced reactions of these two indexes. In the second part of the study, in comparison with control group, NE concentration in cerebral cortex of CI-R-3min group increased significantly (P<0.05); while NE content of CI-R-3min+EA group was significantly lower than that of CI-R-3min group (P<0.05). No significant difference was found between CI-R-3min group and control group in cortical NE levels; and no significant changes were found about NE levels in CI-R-48h and CI-R-48h+EA groups, suggesting that EA could inhibit the increase of cortical NE level in the early stage of CI. Conclusion: Changes of NE concentration in the cerebral cortex during the earlier period of CI-R is possibly related to the incidence of cortical apoptosis. EA can reduce the increase of NE due to CI and thus may inhibit CI-induced cortical apoptosis.

Effects and mechanism of different adrenergic receptor antagonists on left ventricular hypertrophy subsequent to coarctation of abdominal aorta in rats

Objective: To study the changes of a collagen-binding protein (Colligin) and myosin heavy chain isoform (α/β-MHC) gene and protein in left ventricular hypertrophy subsequent to coarctation of abdominal aorta in rats and the effects of three kinds of adrenergic receptor blockers: Carvedilol (CAR) , Metoprolol (MET) and Terazosin (TER) on these changes, and to elucidate the effects and new mechanism of CAR on left ventricular hypertrophy regression. Methods: A model of hypertrophy induced by coarctation of abdominal aorta(CAA)was used in this study. Thirty two male wistar rats were divided randomly into four groups 4 weeks after CAA operation: CAA, CAR, MET and TER. Hemodynamics, ventricular remodeling parameters, expressions of Colligin and α/β-MHC mRNA, protein expressions of Collagen Ⅰ / Ⅲ and Colligin were investigated in the four groups and sham operation group. Results: Left ventricle hypertrophy was observed clearly 16 weeks after operation. The ratio of α/β-MHC mRNA decreased, while expressions of Collagen Ⅰ /Ⅲ proteins and Colligin mRNA/protein increased( P < 0.05). CAR could ameliorate left ventricle hypertrophy prior to MET and TER. CAR could also change the expressions of α/β-MHC, Collagen Ⅰ /Ⅲ and Colligin in both gene and protein levels ( P < 0.05), while MET and TER have no effect on them ( P > 0.05). Conclusion: The effects of CAR on extracellular matrix proteins and MHC isoform shift regression of left ventricle may be due to antiproliferative or antioxidative mechanism, which was independent of beta-adrenergic receptor antagonist.

Features of intervertebral disc degeneration in rat's aging process

Objective:The age-related change is important part of degenerative disc disease. However,no appropriate animal model or objective evaluation index is available. This study aimed to investigate the features of intervertebral disc degeneration in aging process of rats. Methods:22-month-old Sprague-Dawley(SD) rats were used as spontaneously occurring intervertebral disc degeneration models and 6-month-old rats as young controls. Expression of collagen types II and X was measured by immunohistochemistry. Degenerations of intervertebral discs were scored according to Miyamoto's method. Numbers and areas of afferent vascular buds were measured. The thicknesses of non-calcified and calcified layers were measured and statistically analyzed. Results:There were less collagen type II expression and more collagen type X expression in the calcified layer of the cartilage endplates and nucleus pulposus in the rats of the aged group than in the young control. There were fewer and smaller afferent vascular buds in the rats of the aged group than in the young control group. The ratio of the non-calcified to the calcified layers in the rats of the aged group significantly decreased,compared with that of the young control group(P<0.01) . Conclusion:Rats can spontaneously establish intervertebral disc age-related degeneration. The expression of collagen types II and X,numbers and areas of afferent vascular buds,the ratio of the non-calcified to the calcified layers,and water and glycosaminoglycan contents in the nucleus pulposus are sensitive indexes of intervertebral disc degeneration.

Initial gut microbiota structure affects sensitivity to DSS-induced colitis in a mouse model

The dextran sulfate sodium (DSS)-induced colitis model is a widely applied mouse model, but controversial results have been obtained from experiments using the same mouse strain under the same conditions. Because the gut microbiota play an important role in DSS-induced colitis, it is essential to evaluate the influence of the initial gut microbiota in this model. Here, we identified significant variations in the initial gut microbiota of different batches of mice and found that the initial intestinal microbiota had a profound influence on DSS-induced colitis. We performed three independent trials using the same C57BL/6J mouse model with DSS treatment and used high-throughput 16S rRNA gene sequencing to analyze the gut microbiota. We found that the structure and composition of the gut microbiota in mice with severe colitis, as compared with mice with milder colon damage, had unique features, such as an increase in Akkermansia bacteria and a decrease in Barnesiella spp. Moreover, these varied gut bacteria in the different trials also showed different responses to DSS treatment. Our work suggests that, in studies using mouse models, the gut microbiota must be considered when examining mechanisms of diseases, to ensure that comparable results are obtained.

Why not to avoid the smell of danger？ Unexpected behavior of the Cypriot mouse surviving on the island invaded by black rats

Mus cypriaeus is a recently discovered endemic species that evolved about half a million years ago on the Cyprus Is- land in an absence of most mammalian predators and competitors. As on other Mediterranean islands, the faunal composition was dramatically changed by the invasion of commensal and domestic species following Holocene colonization by humans. We exa- mined the behavioral responses of the Cypriot mouse to the odors of these new competitors （black and Norway rat, house mouse and spiny-mouse） and predator （domestic cat） as well as controls （Herb-field mouse, guinea pig）. We compared them with those of mainland population of house mouse from Syria with different coexistence history. Surprisingly, the Cypriot mouse failed to avoid the odor of its current main competitor, the black rat. Moreover, the response patterns of both the Cypriot and Syrian house mice to the examined odor sources appeared fairly comparable. There was a clear tendency to prefer odors of other murids over unscented sawdust as well as to avoid the odor of a domestic cat. In conclusion, neither the long-term isolation from predators nor the recent strong competition with black rats affected mice eompetitory and antipredatory responses fundamentally [Current Zoology 61 （4）： 781-791, 2015].

Effect of electroacupuncture on gene expression in calcium signaling pathway in hippocampal cells in mice with cerebral ischemia reperfusion

OBJECTIVE:To observe the regulation of electroacupuncture on gene expression at calcium signaling pathways in mice with cerebral ischemia reperfusion.METHODS:Sixty male, inbred Kunming mice were randomly assigned to three groups:repeated cerebral ischemia reperfusion group(RG, n = 24),sham-operated group(SG, n = 12), and electroacupuncture group(EG, n = 24).Mice in RG and EGgroups were modeled by repeated cerebral ischemia reperfusion surgery, and EG mice were treated with electroacupuncture for 30 min after recovery from anesthesia.Changes in gene expression profile of mice hippocampi were analyzed by global expression profile microarray.Genes that were up-regulated or down-regulated greater than 1.5folds were considered to be biologically meaningful.Real-time quantitative polymerase chain reaction(q-PCR) method was used to verify the expression of selected genes based on the algorithm [2^(ΔΔCt)].RESULTS:Compared with SG mice, 242 genes showed different in expressions in RG mice:107down-regulated and 135 up-regulated.Compared with RG mice, 609 genes showed a difference of expression in EG mice:315 down-regulated and 375up-regulated.Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated two pathways:calcium signaling and long-term potentiation in which 11 differentially expressed genes selected.Six of the 11 genes in the calcium signaling pathway were verified after real-time q-PCR testing.CONCLUSION:Electroacupuncture treatment of cerebral ischemia reperfusion appears to regulate Atp2a2, Cacna1 e, Camk2 a, Gnas, Grm1, Rapgef3 genes in the calcium signaling pathway.