Artificial rearing of rat pups using rat milk

The contribution of diet and surgery to the brain weight deficits observed in artificially reared rats was investigated. Four day old Long Evans rat pups were assigned to an artificially reared (AR) or mother reared (MR) group. AR pups were encannulated and fed either rat milk (AR-MOM) or replacement formula (AR-MES). MR pups received a sham encannulation (MR-SHAM) or no surgery (MR-CONT) before being returned to their dam for rearing. On day 7 all the animals were killed. Brain weights and visceral organ weights were obtained. There was no significant difference between the MR groups on any measure except stomach weights. AR-MOM pups had larger visceral organ weights than pups in the other groups. AR-MOM and AR-MES pups had similar whole brain weights, smaller than those of the MR pups. However, the cerebellar weights, and to a lesser extent, brainstem weights, showed improvements in the AR-MOM group, over the AR-MES group. Neither the effect of surgery nor of diet alone can account for the organ weight differences that have been described in AR rats. The possibility that normal growth may be primarily dependent on diet at one stage of development, with other factors gaining importance at later stages is discussed.     

Transplantation of postnatal rat enteric ganglia into denervated adult rat hippocampus

These experiments explore the possible value of the myenteric plexus as a source of donor cells for autografting into the central nervous system. Neurons and glia from 10-12-day postnatal rat myenteric plexus survive for at least one month after transplantation into cholinergically denervated syngeneic adult rat hippocampus. A population of donor cholinergic neurons has acetylcholinesterase-positive processes, but these appear not to innervate host tissue. Host gliosis in response to these implants seems to be less than that seen with other peripheral ganglia, and unlike Schwann cells, the enteric glia form end-feet on brain capillaries.     

Replication of rat coronavirus in a rat cell line,LBC

Summary Rat coronavirus readily propagated and induced marked cytopathic effect in a rat cell line, LBC cell culture, which provided a sensitive, practical assay system for viral infectivity and neutralizing antibody, and a satisfactory source of the virus.With 3 Figures     

Activation of rat complement by soluble and insoluble rat IgA immune complexes

The ability of rat monoclonal IgA, specific for 2,4-dinitrophenyl (DNA), to activate the complement (C) system of the rat was investigated using aggregated IgA or IgA immune complexes (IC). IgA was coated onto a solid phase, and tested for its capacity to bind C3 upon incubation at 37 degrees C in normal rat serum (NRS) in the presence of Mg-EGTA. Binding of C3 was observed dependent on the dose of dimeric (d-), polymeric (p-) and secretory IgA tested. In contrast, little C3 fixation was observed in this system with monomeric (m-) rat IgA or with mouse m- and d-IgA (MOPC315). Soluble and insoluble rat IgA IC were prepared using dinitrophenylated rat serum albumin (DNP8RSA) as antigen (Ag), and assessed for C activation. It was shown that insoluble IC (immune precipitates; IP) containing m-, d- or pIgA of rat origin activate the alternative pathway of rat C, as demonstrated by their capacity to induce C consumption in NRS in the presence of Mg-EGTA. When p- and m-IgA IP were compared for their capacity to activate C, it was found that p-IgA activated C four times as efficiently as m-IgA IP (at 2 mg/ml). Soluble rat IgA IC were prepared in an excess of DNP8RSA, fractionated by gel filtration on Sepharose 6B, and analyzed for C activation and antibody (Ab)/Ag ratio. In contrast to m-IgA IP, soluble m-IgA did not activate C. On the other hand soluble d-IgA IC activated C dependent on their concentration and size: at a concentration of 0.1 mg/ml high-molecular weight d-IgA IC with a high Ab/Ag ratio were four times as efficient as low-molecular weight IC with a low Ab/Ag ratio, and twice as efficient as IP prepared at equivalence. To demonstrate the induction by IgA of the assembly of the terminal membrane attack complex, trinitrophenyl (TNP)-conjugated rat red blood cells (TNP-RRBC) coated with d- or p-IgA were shown to be lysed in NRS in the presence of Mg-EGTA. No lysis of m-IgA-coated TNP-RRBC was observed. The results in this study demonstrate that both soluble and insoluble rat IgA IC activate the alternative pathway of homologous rat C. Alternative pathway activation by soluble rate IgA IC is dependent on the size of the IC. The degree of polymerization of the IgA Ab itself also influences C activation.     

宫内注射胎肝细胞对大鼠移植免疫反应的影响

目的研究宫内注射胎肝细胞对大鼠移植免疫反应状态的影响。方法将LOU/CN大鼠的胎肝细胞注射于宫内CHN胎鼠的腹腔。以分娩7～9wk龄时的CHN雌性大鼠作为受体,LOU/CN雌性大鼠作为供体,进行皮片移植。观察大鼠皮片移植物的存活时间,并以混合淋巴细胞培养检查移植排斥反应。结果与对照组相比较,宫内注射组大鼠皮片移植物的存活时间明显延长。混合淋巴细胞培养显示,移植排斥反应被明显抑制(P<0.01)。结论胎肝细胞宫内注射于胎鼠可延长大鼠皮片移植物的存活期,对移植排斥反应产生明显的抑制作用。     

严重烧伤大鼠血清对脂肪间质干细胞生物学特性的影响

目的 探讨严重烧伤大鼠血清对体外培养的大鼠脂肪间充质干细胞(ADSCs)生物学特性的影响.方法 取雄性SD大鼠双侧腹股沟脂肪组织,采用胶原酶消化法、分离纯化大鼠ADSCs,取第3代细胞,采用流式细胞仪检测细胞表面标志物,行成脂成骨诱导分化鉴定;ADSCs传代后按随机数字表法分为10％胎牛血清组(正常培养组)、10％正常大鼠血清组,10％烧伤大鼠血清组,采用噻唑蓝(MTT)法测定各组细胞的生长曲线.通过流式细胞仪检测各组细胞的生长周期、Real-time PCR法检测各组细胞血管内皮生长因子(VEGF)、凋亡相关因子Caspase-3的表达情况.结果 分离培养的ADSCs传至第3代时形态规则,经流式细胞仪检测,所培养的ADSCs均表达CD29、CD90、CD105,阳性率分别为88.6％、99.7％、92.8％,而CD31、CD34、CD45阳性率分别为4.4％、4.7％、3.3％;经诱导培养后可向成骨成脂分化.MTT法检测结果显示:10％烧伤大鼠血清组细胞增殖较快,各时间点吸光度值(A值)明显高于10％胎牛血清组及10％正常大鼠血清组.流式细胞仪检测结果显示:培养1周后10％烧伤大鼠血清组、10％正常大鼠血清组、10％胎牛血清组ADSCs G1期细胞比例分别为:(72.20±5.13)％、(83.50±4.74)％、(90.20±6.37)％;S期细胞比例分别为:(21.40±2.84)％、(12.50±1.96)％和(8.60±1.31)％,10％烧伤大鼠血清组ADSCs G1期细胞比例显著低于10％正常大鼠血清组、10％胎牛血清组(t=2.39、4.86;P ＜0.05);10％烧伤大鼠血清组ADSCs S期细胞比例显著高于10％正常大鼠血清组、10％胎牛血清组(=5.54,7.93;P＜0.01).Real-Time PCR检测结果显示:10％烧伤大鼠血清组VEGF的表达明显上调,Caspase-3表达显著下调与10％正常大鼠血清组、10％胎牛血清组相比差异均有统计学意义(P＜0.05).结论 10％烧伤大鼠血清可明显促进ADSCs的增殖、抑制细胞凋亡发生、促进ADSCs的分泌功能,严重烧伤后可望移植ADSCs用?     

青老年大鼠脑缺血模型的比较

背景：大鼠具有成本低,种系内纯合性好,脑血管解剖特性与人类相似等特点,是目前脑缺血研究最常用的实验动物。 目的：观察青老年大鼠大脑中动脉梗死后的行为学变化,分析年龄对脑缺血的影响。 方法：将青、老年SD大鼠随机分为青、老年假手术组,青、老年模型组(同侧颈总动脉永久结扎大脑中动脉线栓法制备大脑中动脉梗死模型)4组。 结果与结论：老年假手术组体质量低于青年假手术组(P < 0.05),但高于老年模型组(P < 0.05),老年模型组体质量低于青年模型组(P < 0.05)。术后第1,3,5,7天老年模型组改良神经功能损害程度评分高于青年模型组(P < 0.05);与青年模型组及青、老年假手术组比较,术后第3,8,12周老年模型组逃避潜伏期明显延长,跨过平台所在位置的次数明显减少(P < 0.05)。表明在同等缺血打击下,老龄鼠脑缺血模型缺血损伤重、修复能力低,其神经功能恢复、学习和记忆能力明显逊于青年大鼠,提示增龄因素是研究脑缺血后神经损伤的重要影响因素之一。 关键词：大脑中动脉梗死;动物模型;改良神经损害程度评分;学习;记忆;组织构建实验造模  doi:10.3969/j.issn.1673-8225.2012.11.024     

Ultrastructure of cultured rat neostriatum

Four different types of neurons were identified in cultures of newborn rat neostriatum. Small and medium-sized neurons were most numerous. A few large neurons and some very small ‘microneurons’ were observed. The morphology of medium-sized neurons varied, and this group may contain more than one functional subgroup. Axosomatic synapses were associated with all types of neurons, but most of them made contacts with medium-sized neurons. All axodendritic synapses made symmetrical contacts, with or without synaptic membrane thickenings. A great majority of terminal boutons contained small, round, clear vesicles. A few terminals with large pleomorphic clear vesicles were seen. Large granular vesicles were found in the peripheral cytoplasm of some medium-sized neurons, dendrites and axon terminals. No terminals contained exclusively large granular vesicles, but in some terminals they were more numerous than the small clear vesicles. The dense core of the large granular vesicles was resistant to reserpine treatment. Kainic acid did not cause specific degenerative changes. The presence of several morphologically distinct populations of neurons renders it possible to study the nature of these cells in different experimental conditions. Intrinsic neostriatal synaptic contacts appeared to be symmetrical, although it is possible that some of them have the capacity to develop asymmetrical contacts. The lack of effect of kainic acid may be explained by the early maturational stage of the cells or by the lack of extrinsic contacts. More functional studies are necessary before the usefulness of these cultures for investigating neostriatal function can be assessed.     

Transport of sulphate in rat jejunal and rat proximal tubular basolateral membrane vesicles

Basolateral membrane vesicles were isolated by a Percoll density gradient centrifugation method from small intestinal and renal proximal tubular epithelial cells. Transport of sulphate across the basolateral membrane was analyzed by measuring the uptake of tracer sulphate.In both membrane preparations, preloading the vesicles with sulphate-or hydroxyl-anions stimulated tracer sulphate uptake (trans-stimulation); an inwardly directed sodium gradient did not stimulate sulphate influx whether in the absence or in the presence of sulphate- or hydroxyl-iontrans-stimulation. Under sulphate trans-stimulation conditions, DIDS (10^–4 mol/l) inhibited sulphate influx.In intestinal membranes, trans-stimulation of sulphate influx was obtained by preloading the vesicles with chloride, in renal membranes by preloading with bicarbonate. Under sulphate trans-stimulation conditions, in intestinal membranes, sulphate influx was strongly inhibited by chloride, in renal membranes, chloride inhibition was absent. Under bicarbonate trans-stimulation conditions, in renal membranes, sulphate transport was inhibited by lactate.It is concluded that small intestinal and renal proximal tubular basolateral membrane vesicles contain a transport mechanism for sulphate that cannot be energized by a sodium gradient. The transport system in small intestinal basolateral membranes seems to be different from that in renal membranes. It is suggested that the observed interaction between inorganic and organic anion transport in renal basolateral membranes is indirect.Abbreviations DIDS 4,4-Diisothiocyano-2,2-disulfonic acid stilbene - DTT dithiothreitol - HEPES N-2-hydroxyethylpiperazine-N-ethanesulfonic acid - MES N-morpholinoethanesulfonic acid - PAH p-aminohippuric acid - PMSF phenylmethylsulfonyl fluoride - SITS 4-acetamido-4-isothiocyanostilbene-2,2-disulfonate - TMA tetramethylammonium - Tris tris(hydroxymethyl)aminomethane