C57BL6 mice

C57BL6 小鼠
  • 文章类型: Journal Article
    雄激素性脱发(AGA)影响全世界的男性和女性。新血管的形成可以恢复血液供应并刺激头发再生周期。最近,我们的研究小组报告说,在体外模型和小鸡生物测定中,2-脱氧-D-核糖(2dDR)在刺激新生血管形成方面的有效率是VEGF的80%-90%.在这项研究中,我们旨在评估2dDR对头发生长的影响。我们制备了含有2dDR的藻酸盐凝胶,聚丙二醇,和苯氧乙醇.通过腹膜内注射睾酮(TE)在C57BL6小鼠中形成AGA。使用二氢睾酮(DHT)治疗组作为阴性对照,米诺地尔组用作阳性对照,我们包括使用2dDR凝胶以及2dDR和米诺地尔组合治疗的组。每个处理应用20天。用2dDR凝胶和米诺地尔处理的两组刺激毛囊的形态发生。H&E染色的C57BL/6小鼠的皮肤切片显示长度增加,直径,毛囊密度,生长期/静止期比率,毛囊的直径,被黑色素覆盖的毛球区域,血管数量的增加.Masson的三色染色显示黑色素覆盖的毛球面积增加。FDA批准的药物(米诺地尔)对头发生长的影响与2dDR相似(80%-90%)。通过应用米诺地尔与2dDR的组合没有观察到显著的益处。我们得出的结论是,2DDR凝胶具有治疗雄激素性脱发和其他可能需要刺激头发再生的脱发疾病的潜力,比如化疗后。2dDR的活性机制尚待建立。
    Androgenic alopecia (AGA) affects both men and women worldwide. New blood vessel formation can restore blood supply and stimulate the hair regrowth cycle. Recently, our group reported that 2-deoxy-D-ribose (2dDR) is 80%-90% as effective as VEGF in the stimulation of neovascularization in in vitro models and in a chick bioassay. In this study, we aimed to assess the effect of 2dDR on hair growth. We prepared an alginate gel containing 2dDR, polypropylene glycol, and phenoxyethanol. AGA was developed in C57BL6 mice by intraperitoneally injecting testosterone (TE). A dihydrotestosterone (DHT)-treated group was used as a negative control, a minoxidil group was used as a positive control, and we included groups treated with 2dDR gel and a combination of 2dDR and minoxidil. Each treatment was applied for 20 days. Both groups treated with 2dDR gel and minoxidil stimulated the morphogenesis of hair follicles. H&E-stained skin sections of C57BL/6 mice demonstrated an increase in length, diameter, hair follicle density, anagen/telogen ratio, diameter of hair follicles, area of the hair bulb covered in melanin, and an increase in the number of blood vessels. Masson\'s trichrome staining showed an increase in the area of the hair bulb covered in melanin. The effects of the FDA-approved drug (minoxidil) on hair growth were similar to those of 2dDR (80%-90%). No significant benefit were observed by applying a combination of minoxidil with 2dDR. We conclude that 2dDR gel has potential for the treatment of androgenic alopecia and possibly other alopecia conditions where stimulation of hair regrowth is desirable, such as after chemotherapy. The mechanism of activity of 2dDR remains to be established.
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  • 文章类型: Journal Article
    在阿尔茨海默病和相关tau蛋白病的临床前研究中,tau磷酸化分析通常用于细胞和动物模型。然而,认识到tau磷酸化对各种外在因素的敏感性,特别是温度,对实验准确性至关重要。体温过低可引发tau过度磷酸化,而热疗导致其去磷酸化。然而,tau磷酸化对无意温度变化的反应速度仍然未知。在细胞培养中,最显著的温度变化发生在收获前从培养箱中取出细胞时,在动物模型中,安乐死前麻醉期间。在这项研究中,我们研究了N2a和SH-SY5Y神经元细胞系中tau磷酸化的动力学,以及暴露于麻醉的小鼠。我们观察到在将细胞培养物从其37°C培养箱转移至室温条件后的几秒钟内tau磷酸化的变化。然而,孵育后直接置于冰上的细胞表现出可忽略的磷酸化变化。在体内,异氟烷麻醉迅速导致tau蛋白过度磷酸化,在小鼠失去踏板退缩反射所需的几秒钟内.这些发现强调了在针对tau的研究中防止温度变化的至关重要性。为了确保结果准确,我们建议在安乐死前避免麻醉,并在从培养箱中取出后及时将细胞置于冰上。通过控制温度波动,tau磷酸化研究的信度和效度可以显著提高。
    In preclinical research on Alzheimer\'s disease and related tauopathies, tau phosphorylation analysis is routinely employed in both cellular and animal models. However, recognizing the sensitivity of tau phosphorylation to various extrinsic factors, notably temperature, is vital for experimental accuracy. Hypothermia can trigger tau hyperphosphorylation, while hyperthermia leads to its dephosphorylation. Nevertheless, the rapidity of tau phosphorylation in response to unintentional temperature variations remains unknown. In cell cultures, the most significant temperature change occurs when the cells are removed from the incubator before harvesting, and in animal models, during anesthesia prior to euthanasia. In this study, we investigate the kinetics of tau phosphorylation in N2a and SH-SY5Y neuronal cell lines, as well as in mice exposed to anesthesia. We observed changes in tau phosphorylation within the few seconds upon transferring cell cultures from their 37°C incubator to room temperature conditions. However, cells placed directly on ice post-incubation exhibited negligible phosphorylation changes. In vivo, isoflurane anesthesia rapidly resulted in tau hyperphosphorylation within the few seconds needed to lose the pedal withdrawal reflex in mice. These findings emphasize the critical importance of preventing temperature variation in researches focused on tau. To ensure accurate results, we recommend avoiding anesthesia before euthanasia and promptly placing cells on ice after removal from the incubator. By controlling temperature fluctuations, the reliability and validity of tau phosphorylation studies can be significantly enhanced.
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  • 文章类型: Journal Article
    碳点(CD)是易于获得的纳米颗粒,具有广泛的生物活性;但是,它们长期暴露后的毒性研究甚少。所以,表面富含羟基化烃链和亚甲基(CD_GE)的CD的体外和体内毒性,羧基和苯酚基带氮(CD_3011),旨在发现三氟甲基(CDF19)或甲苯胺和苯胺基团(CDN19)。在A549细胞上评估CDs的体外毒性(阻抗的实时细胞分析,荧光显微镜)孵育24小时后,我们没有观察到细胞活力和形态的变化。在多次给药(5mg/kg皮下)14天后,对C57Bl6小鼠评估CDs的体内毒性。CDN19和CD_3011组在不同的给药天数观察到致死性(高达50%),在CD_3011的情况下伴有毒性症状。除尿素外,血清生化指标无明显变化(CDF19和CD_3011组升高),也不是实质性的肾脏,肝脏,和脾脏损伤。对所有器官影响最大的还有CD_3011和CDF19,引起肾小管损伤和肝脏血液供应中断。因此,具有富含含氧和含氮官能团的表面的CD在每天多次给药后可能是有毒的,没有,然而,存活动物内脏器官的重大损害。
    Carbon dots (CDs) are easy-obtained nanoparticles with wide range of biological activity; however, their toxicity after prolonged exposure is poorly investigated. So, in vitro and in vivo toxicity of CDs with the surfaces enriched with hydroxylated hydrocarbon chains and methylene groups (CD_GE), carboxyl and phenol groups accompanied with nitrogen (CD_3011), trifluoromethyl (CDF19) or toluidine and aniline groups (CDN19) were aimed to be discovered. CDs\' in vitro toxicity was assessed on A549 cells (real-time cell analysis of impedance, fluorescence microscopy) after 24 h of incubation, and we observed no changes in cell viability and morphology. CDs\' in vivo toxicity was assessed on C57Bl6 mice after multiple dosages (5 mg/kg subcutaneously) for 14 days. Lethality (up to 50%) was observed in CDN19 and CD_3011 groups on different days of dosing, accompanied by toxicity signs in case of CD_3011. There were no changes in serum biochemical parameters except Urea (increased in CDF19 and CD_3011 groups), nor substantial kidney, liver, and spleen injuries. The most impactful for all organs were also CD_3011 and CDF19, causing renal tubule injury and liver blood supply violation. Thus, CDs with a surface enriched with oxygen- and nitrogen-containing functional groups might be toxic after multiple everyday dosing, without, however, significant damages of internal organs in survived animals.
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  • 文章类型: Journal Article
    迷迭香(迷迭香)是一种常见的家用植物,具有针状叶子和白色花朵,属于唇形科,具有多种药用特性,包括头发和头皮疾病,心血管,神经紊乱,等。,在目前的工作中,我们专注于配制和评估1%的头发洗液中掺入了R.officinalis的甲醇提取物。
    用甲醇提取植物的地上部分,然后通过化学测试鉴定植物化学物质的性质。它显示了蛋白质的存在,氨基酸,脂肪和油,类固醇,糖苷,酚类化合物,黄酮类化合物,挥发油,和维生素。将提取物配制成合适的毛发洗剂,然后评价其各种质量控制参数。最后,评估洗剂对C57BL/6小鼠的毛发生长促进活性,使用水作为对照和2%米诺地尔润发液作为标准。
    观察到配制的1%草本毛发洗剂通过了所有评价参数,并且显示出比标准药物处理的动物显著的毛发生长促进活性。
    尽管已经对迷迭香进行了一些研究,首次对添加植物地上部分提取物的护发液配方进行研究。由于我们的配方表现出优异的活性,它可以很好地认为是一种替代市售的头发生长促进剂有很多不想要的效果。
    UNASSIGNED: Rosmarinus officinalis (rosemary) is a common household plant with needle-like leaves and white flowers that belongs to the family Lamiaceae and has various medicinal properties including ailments of hair and scalp, cardiovascular, nervous disorders, etc., In the current work, we have focused on formulation and evaluation of 1% hair lotion incorporated with methanolic extract of R. officinalis.
    UNASSIGNED: The aerial parts of the plant were extracted with methanol and then the nature of phytochemicals were identified by chemical tests. It showed the presence of proteins, amino acids, fats and oils, steroids, glycosides, phenolic compounds, flavonoids, volatile oil, and vitamins. The extract was formulated to a suitable hair lotion and then evaluated for its various quality control parameters. Finally, the lotion was evaluated for hair growth promoting activity on C57BL/6 mice, using water as control and 2% minoxidil hair lotion as standard.
    UNASSIGNED: It was observed that the formulated 1% herbal hair lotion passed all the evaluation parameters and showed a significant hair growth promoting activity than the standard drug-treated animals.
    UNASSIGNED: Although several researches have been carried out on the rosemary, an investigation on formulation of hair lotion adding the extract of the aerial part of the plant is for the first time. Since our formulation exhibited an excellent activity, it can be well thought out to be an alternative to the commercially available hair growth promoters with a lot of unwanted effects.
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  • 文章类型: Journal Article
    低氧和高碳酸血症信号通路之间的相互作用,在小鼠中尚未系统地确定同时发生的低氧高二氧化碳气体攻击(HH-C)期间和之后发生的通气变化。在未麻醉的雄性C57BL6小鼠中的这项研究解决了以下假设:缺氧(HX)和高碳酸血症(HC)信号传导事件显示出一系列相互作用,表明周围和中枢呼吸机制的协调。我们评估了低氧引起的通气反应(HX-C,10%,O2,90%N2),高碳酸血症(HC-C,5%CO2,21%,O2,90%N2)和HH-C(10%O2,5%,CO2,85%N2)挑战,以确定HH-C挑战引起的通气反应是否只是HX-C和HC-C引起的反应的累加,或者是否存在其他互动模式。HH-C引起的响应是潮气量的累加,分钟通气和呼气时间,在其他人中。HH-C引起的响应是HX-C和HC-C响应的低加性(即,通过简单添加HX-C和HC-C反应)呼吸频率,HH-C反应低于预期,吸气时间和松弛时间,在其他人中。此外,呼气末暂停在HX-C期间增加,但在HC-C期间下降,和HH-C,因此表明HC-C反应影响同时给予的HX-C反应。返回室内空气的反应对于潮气量和每分钟通风是附加的,其中,而它们对于呼吸频率来说是低加性的,吸气时间,峰值吸气流量,呼吸暂停,吸气和呼气驱动和排斥指数。这些数据显示HX-C和HH-C信号传导途径在加性和经常是次加性过程中彼此相互作用。
    Interactions between hypoxic and hypercapnic signaling pathways, expressed as ventilatory changes occurring during and following a simultaneous hypoxic-hypercapnic gas challenge (HH-C) have not been determined systematically in mice. This study in unanesthetized male C57BL6 mice addressed the hypothesis that hypoxic (HX) and hypercapnic (HC) signaling events display an array of interactions indicative of coordination by peripheral and central respiratory mechanisms. We evaluated the ventilatory responses elicited by hypoxic (HX-C, 10%, O2, 90% N2), hypercapnic (HC-C, 5% CO2, 21%, O2, 90% N2), and HH-C (10% O2, 5%, CO2, 85% N2) challenges to determine whether ventilatory responses elicited by HH-C were simply additive of responses elicited by HX-C and HC-C, or whether other patterns of interactions existed. Responses elicited by HH-C were additive for tidal volume, minute ventilation and expiratory time, among others. Responses elicited by HH-C were hypoadditive of the HX-C and HC-C responses (i.e., HH-C responses were less than expected by simple addition of HX-C and HC-C responses) for frequency of breathing, inspiratory time and relaxation time, among others. In addition, end-expiratory pause increased during HX-C, but decreased during HC-C and HH-C, therefore showing that HC-C responses influenced the HX-C responses when given simultaneously. Return to room-air responses was additive for tidal volume and minute ventilation, among others, whereas they were hypoadditive for frequency of breathing, inspiratory time, peak inspiratory flow, apneic pause, inspiratory and expiratory drives, and rejection index. These data show that HX-C and HH-C signaling pathways interact with one another in additive and often hypoadditive processes.NEW & NOTEWORTHY We present data showing that the ventilatory responses elicited by a hypoxic gas challenge in male C57BL6 mice are markedly altered by coexposure to hypercapnic gas challenge with hypercapnic responses often dominating the hypoxic responses. These data suggest that hypercapnic signaling processes activated within brainstem regions, such as the retrotrapezoid nuclei, may directly modulate the signaling processes within the nuclei tractus solitarius resulting from hypoxic-induced increase in carotid body chemoreceptor input to these nuclei.
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  • 文章类型: Journal Article
    在创伤后骨关节炎(PTOA),软骨下骨(SB)的低矿化和重塑增加是组织改变的第一阶段。尽管这些改变被很好地描述,并且是OA干预的主要目标之一,OA进展过程中SB成分和机械性能变化之间的联系在文献中仍然很少。这里,我们假设SB显示-在步态模式改变的第一个迹象之后-SB组织形成的减少,描述为(i)厚度减少,(ii)较低的纳米级刚度,和(iii)矿物质和胶原蛋白成熟度降低。为了检验我们的假设,我们通过步态分析研究了雌性C57Bl6小鼠右膝的PTOA(n=13对照组[CL]和n=27PTOA组),组织形态计量学,纳米压痕,和拉曼光谱(RS)。我们显示(i)OA组织学分级增加,(ii)软骨和SB厚度减少,(ii)增加站立时间和四肢的步幅。具有PTOA的小鼠的外侧髁-施加主要力的外侧髁的矿化程度和晶体尺寸降低,并呈现较低的弹性模量(E)。然而,虽然在胶原蛋白或矿物质相关成分RS特性方面没有观察到差异,在PTOA组中,内髁的结晶度高于外髁,我们在对照组中没有观察到。我们的研究描述了中等PTOA的早期发作,其中SB纳米级刚度降低,而矿化程度尚未严重改变。
    In Post Traumatic Osteoarthritis (PTOA), hypomineralization and increased remodeling of the Subchondral bone (SB) are the first stages of tissue alterations. Although these alterations are well depicted and one of the main targets in OA intervention, the link between SB compositional and mechanical properties alterations during OA progression remains scarce in the literature. Here, we hypothesized that SB shows - right after the first sign of gait pattern changes - a decrease in SB tissue formation depicted by (i) a decrease in thickness, (ii) a lower nanoscopic stiffness, and (iii) a decrease in mineral and collagen maturity. To test our hypothesis, we investigated PTOA in female C57Bl6 mice\'s right knee (n = 13 control group [CL] and n = 27 PTOA group) by using Gait Analysis, Histomorphometry, Nanoindentation, and Raman Spectroscopy (RS). We showed (i) an increased OA histological grade, (ii) a decrease in Cartilage and SB thickness, and (ii) an increase of stance time and stride length on both limbs. The lateral condyle - where the main forces were applied - of mice with PTOA decreased in the degree of mineralization and crystal size and presented a lower Modulus of Elasticity (E). However, while no difference was observed regarding collagen or mineral-related compositional RS properties, we depicted higher crystallinity in the medial condyle than the lateral condyle in the PTOA group, which we did not observe in the control group. Our study depicts an early onset of intermediate PTOA where SB nanoscopic stiffness decreases while the degree of mineralization is not severely altered yet.
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  • 文章类型: Journal Article
    这项研究的目的是研究β-氨基丙腈(BAPN)对啮齿动物动脉壁的影响,并分析不同浓度或剂量的BAPN处理的啮齿动物的动脉和其他组织的总体或病理变化。
    18只SPFSD大鼠(4-5周龄)分为3组:SD-0.2(A组),SD-0.4(B组),和SD-0.6(C组)。A组,B和C分别为0.2%,0.4%,和0.6%的BAPN溶液,分别,喝了七个星期的水。将40只SPFC57BL/6小鼠(3周龄)随机分为四组:C57-0.2(D组),C57-0.4(E组),C57-0.6(F组)和对照组,给予0.2%,0.4%,或0.6%BAPN或蒸馏水作为饮用水,分别,七个星期。所有实验动物都可以自由喝水。解剖主动脉并目视检查。同时,在主动脉组织中进行苏木精和伊红(HE)染色。用IPP(Image-ProPlus6.0)测量中膜的血管直径和面积。
    BAPN处理显着影响大鼠和小鼠的饮水量和体重增加。BAPN还导致大鼠和小鼠主动脉膜增厚,以及弹性纤维排列的不规则性。这些病理变化类似于在人类动脉瘤中观察到的病理变化。C57小鼠夹层动脉瘤的发生率高于SD大鼠。
    浓度为0.4%的BAPN可用于产生解剖动脉瘤的动物模型。在SD大鼠中,病理变化和其他并发症的发生率,如肠破裂和脊柱侧凸,高于夹层动脉瘤的发生率。
    UNASSIGNED: The aim of this study was to investigate the effects of beta-aminopropionitrile (BAPN) on the arterial walls of rodents, and to analyze the gross or pathological changes of arterial and other tissues of rodents treated with BAPN at different concentrations or doses.
    UNASSIGNED: Eighteen SPF SD rats (4-5-week old) were divided into three groups: SD-0.2 (Group A), SD-0.4 (Group B), and SD-0.6 (Group C). The groups A, B and C were given 0.2%, 0.4%, and 0.6% BAPN solution, respectively, as drinking water for seven weeks. Forty SPF C57BL/6 mice (3-week old) were randomly divided into four groups: C57-0.2 (Group D), C57-0.4 (Group E), C57-0.6 (Group F) and the control group and given 0.2%, 0.4%, or 0.6% BAPN or distilled water as drinking water, respectively, for seven weeks. All experimental animals were free to drink water. The aortas were dissected and visually examined. At the same time, hematoxylin and eosin (HE) staining was performed in aorta tissue. The vascular diameter and area of the middle membrane were measured with IPP (Image-Pro Plus 6.0).
    UNASSIGNED: BAPN treatment significantly affected the water intake and weight gain of rats and mice. BAPN also caused thickening of the membrane in the aortas of rats and mice, and irregularity in the arrangement of elastic fibers. These pathological changes are similar to the pathological changes observed in human aneurysms. The incidence of dissecting aneurysm in C57 mice was higher than that of Sprague Dawley (SD) rats.
    UNASSIGNED: BAPN at a concentration of 0.4% was feasible to produce an animal model of dissecting aneurysm. In SD rats, the rate of pathological changes and other complications, such as intestinal rupture and scoliosis, was higher than the rates of dissecting aneurysm.
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  • 文章类型: Journal Article
    Arterial pCO2 elevations increase minute ventilation via activation of chemosensors within the carotid body (CB) and brainstem. Although the roles of CB chemoafferents in the hypercapnic (HC) ventilatory response have been investigated, there are no studies reporting the role of these chemoafferents in the ventilatory responses to a HC challenge or the responses that occur upon return to room air, in freely moving mice. This study found that an HC challenge (5% CO2, 21% O2, 74% N2 for 15 min) elicited an array of responses, including increases in frequency of breathing (accompanied by decreases in inspiratory and expiratory times), and increases in tidal volume, minute ventilation, peak inspiratory and expiratory flows, and inspiratory and expiratory drives in sham-operated (SHAM) adult male C57BL6 mice, and that return to room air elicited a brief excitatory phase followed by gradual recovery of all parameters toward baseline values over a 15-min period. The array of ventilatory responses to the HC challenge in mice with bilateral carotid sinus nerve transection (CSNX) performed 7 days previously occurred more slowly but reached similar maxima as SHAM mice. A major finding was responses upon return to room air were dramatically lower in CSNX mice than SHAM mice, and the parameters returned to baseline values within 1-2 min in CSNX mice, whereas it took much longer in SHAM mice. These findings are the first evidence that CB chemoafferents play a key role in initiating the ventilatory responses to HC challenge in C57BL6 mice and are essential for the expression of post-HC ventilatory responses.NEW & NOTEWORTHY This study presents the first evidence that carotid body chemoafferents play a key role in initiating the ventilatory responses, such as increases in frequency of breathing, tidal volume, and minute ventilation that occur in response to a hypercapnic gas challenge in freely moving C57BL6 mice. Our study also demonstrates for the first time that these chemoafferents are essential for the expression of the ventilatory responses that occur upon return to room air in these mice.
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  • 文章类型: Journal Article
    颈上神经节(SCG)节后神经元通过颈交感神经链(CSC)接受节前驱动。SCG伸向颈动脉体等结构(例如,脉管系统,化学敏感性血管球细胞),上气道(例如,舌头,鼻咽),以及整个大脑的实质和脑动脉。我们先前报道过,在假手术(SHAM)自由移动的成年雄性C57BL6小鼠中,低氧气体激发引起了一系列通气反应,并且在双侧颈交感神经链横断(CSCX)的小鼠中,反应发生了变化。由于CSC为SCG提供了节前神经支配,我们推测颈上神经节切除术(SCGX)的小鼠对缺氧气体的反应与CSCX小鼠相似.然而,而SCGX小鼠在CSCX小鼠发生的缺氧气体攻击期间的反应发生了改变(例如,呼吸频率和每分钟通气量的变化发生得更快),SCGX小鼠对低氧气体攻击表现出许多反应,CSCX小鼠没有,包括减少呼吸频率的总增加,分钟通风,吸气和呼气驱动,峰值吸气和呼气流量,和非呼吸的出现。总之,低氧气体攻击可能直接激活SCG细胞亚群,包括节后神经元亚群和小的强荧光(SIF)细胞,独立于CSC驱动器,SCG驱动到这些结构抑制了低氧通气反应的初始发生,同时促进反应的总体规模。SCGX的多种作用可能是由于神经支配对周围和中央结构的丧失,在呼吸控制中具有不同的作用。NEW&NOTEWORTHY我们提供的数据表明,在双侧上颈神经节切除术的雄性C57BL6小鼠中,由低氧气体激发引起的通气反应与双侧颈交感神经链横断的小鼠的报道不同。这些数据表明,缺氧气体攻击可能直接激活上颈神经节(SCG)细胞的亚群,包括小的强烈荧光(SIF)细胞和/或主要的SCG神经元,独立于节前颈交感神经链驱动。
    Superior cervical ganglia (SCG) postganglionic neurons receive preganglionic drive via the cervical sympathetic chains (CSC). The SCG projects to structures like the carotid bodies (e.g., vasculature, chemosensitive glomus cells), upper airway (e.g., tongue, nasopharynx), and to the parenchyma and cerebral arteries throughout the brain. We previously reported that a hypoxic gas challenge elicited an array of ventilatory responses in sham-operated (SHAM) freely moving adult male C57BL6 mice and that responses were altered in mice with bilateral transection of the cervical sympathetic chain (CSCX). Since the CSC provides preganglionic innervation to the SCG, we presumed that mice with superior cervical ganglionectomy (SCGX) would respond similarly to hypoxic gas challenge as CSCX mice. However, while SCGX mice had altered responses during hypoxic gas challenge that occurred in CSCX mice (e.g., more rapid occurrence of changes in frequency of breathing and minute ventilation), SCGX mice displayed numerous responses to hypoxic gas challenge that CSCX mice did not, including reduced total increases in frequency of breathing, minute ventilation, inspiratory and expiratory drives, peak inspiratory and expiratory flows, and appearance of noneupneic breaths. In conclusion, hypoxic gas challenge may directly activate subpopulations of SCG cells, including subpopulations of postganglionic neurons and small intensely fluorescent (SIF) cells, independently of CSC drive, and that SCG drive to these structures dampens the initial occurrence of the hypoxic ventilatory response, while promoting the overall magnitude of the response. The multiple effects of SCGX may be due to loss of innervation to peripheral and central structures with differential roles in breathing control.NEW & NOTEWORTHY We present data showing that the ventilatory responses elicited by a hypoxic gas challenge in male C57BL6 mice with bilateral superior cervical ganglionectomy are not equivalent to those reported for mice with bilateral transection of the cervical sympathetic chain. These data suggest that hypoxic gas challenge may directly activate subpopulations of superior cervical ganglia (SCG) cells, including small intensely fluorescent (SIF) cells and/or principal SCG neurons, independently of preganglionic cervical sympathetic chain drive.
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  • 文章类型: Journal Article
    迄今为止研究的所有哺乳动物物种的同侧上颈神经节(SCG)内的颈交感神经链(CSC)支配神经节后交感神经元。SCG内的神经节后神经元投射到各种各样的结构,包括大脑(实质和脑动脉),上气道(例如,鼻咽和舌)和下颌下腺。SCG还将神经节后纤维发送到颈动脉体(例如,化学敏感的血管球细胞和微循环),然而,这些连接的功能不是在鼠标中建立的。此外,关于CSC-SCG复合物(包括输入颈动脉体)在小鼠中的功能重要性尚不清楚。这项研究的目的是确定CSC双侧横切对通气反应的影响[例如,呼吸频率(Freq)增加,在自由移动的假手术(SHAM)成年雄性C57BL6小鼠中暴露于低氧气体攻击(10%O2和90%N2)期间和之后发生的潮气量(TV)和分钟通气量(MV)],以及在两个CSC都被横切的小鼠(CSCX)中。SHAM和CSCX小鼠的静息通气参数(19个直接记录或计算的参数)相似。CSCX和SHAM小鼠对低氧攻击的反应存在许多重要差异。例如,频率的增加(以及相关的吸气和呼气时间的减少,呼气末暂停,和放松时间),MV的增加,呼气驱动,和呼气流量在50%呼出电视(EF50)发生在CSCX小鼠比在SHAM小鼠更快,尽管两组的总体反应相似.此外,在CSCX小鼠中,峰值吸气流量的初始和总增加较高.此外,在CSCX小鼠中,在低氧攻击的后半期,TV的总体增加更大.在SHAM和CSCX小鼠中,返回室内空气后发生的通气反应基本相似。总的来说,这一新的数据表明,CSC通常可以向外周提供抑制性输入(例如,颈动脉体)和中央(例如,脑干)与C57BL6小鼠对低氧气体攻击的通气反应有关的结构。
    The cervical sympathetic chain (CSC) innervates post-ganglionic sympathetic neurons within the ipsilateral superior cervical ganglion (SCG) of all mammalian species studied to date. The post-ganglionic neurons within the SCG project to a wide variety of structures, including the brain (parenchyma and cerebral arteries), upper airway (e.g., nasopharynx and tongue) and submandibular glands. The SCG also sends post-ganglionic fibers to the carotid body (e.g., chemosensitive glomus cells and microcirculation), however, the function of these connections are not established in the mouse. In addition, nothing is known about the functional importance of the CSC-SCG complex (including input to the carotid body) in the mouse. The objective of this study was to determine the effects of bilateral transection of the CSC on the ventilatory responses [e.g., increases in frequency of breathing (Freq), tidal volume (TV) and minute ventilation (MV)] that occur during and following exposure to a hypoxic gas challenge (10% O2 and 90% N2) in freely-moving sham-operated (SHAM) adult male C57BL6 mice, and in mice in which both CSC were transected (CSCX). Resting ventilatory parameters (19 directly recorded or calculated parameters) were similar in the SHAM and CSCX mice. There were numerous important differences in the responses of CSCX and SHAM mice to the hypoxic challenge. For example, the increases in Freq (and associated decreases in inspiratory and expiratory times, end expiratory pause, and relaxation time), and the increases in MV, expiratory drive, and expiratory flow at 50% exhaled TV (EF50) occurred more quickly in the CSCX mice than in the SHAM mice, although the overall responses were similar in both groups. Moreover, the initial and total increases in peak inspiratory flow were higher in the CSCX mice. Additionally, the overall increases in TV during the latter half of the hypoxic challenge were greater in the CSCX mice. The ventilatory responses that occurred upon return to room-air were essentially similar in the SHAM and CSCX mice. Overall, this novel data suggest that the CSC may normally provide inhibitory input to peripheral (e.g., carotid bodies) and central (e.g., brainstem) structures that are involved in the ventilatory responses to hypoxic gas challenge in C57BL6 mice.
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