盐酸氨溴索、地塞米松产前用药对大鼠胎肺形态发育影响的对比

目的比较产前3d给盐酸氨溴索、地塞米松及单次给地塞米松对大鼠胎肺形态发育的影响。方法孕鼠12只随机分为9g／L盐水对照组和产前盐酸氨溴索3d治疗组、地塞米松3d及1d治疗组4组，每组3只。孕d19每只孕鼠取6只胎鼠肺组织，通过光镜观察及电镜技术比较2种药物及不同疗程对胎肺形态发育的影响。结果1．光镜下3个治疗组每视野肺泡计数、平均肺泡表面积均高于对照组（Pa〈0．01），平均肺泡间隔厚度均低于对照组（Pa〈0．01）。2．光镜下地塞米松3d治疗组每视野肺泡计数、平均肺泡表面积均高于地塞米松1d治疗组，平均肺泡间隔厚度低于地塞米松1d治疗组（Pa〈0．01）。3．光镜下地塞米松3d及1d治疗组每视野肺泡计数、平均肺泡表面积均高于盐酸氨溴索治疗组，平均肺泡间隔厚度低于盐酸氨溴索治疗组（Pa〈0．01）。4．透射电镜观察：治疗组Ⅱ型肺泡上皮内多见板层小体，尤以地塞米松3d治疗组更为多见，且染色深、致密，线粒体等细胞器多；对照组难见板层小体，少见细胞器。结论产前应用地塞米松、盐酸氨溴索均能显著促进胎肺发育；多次地塞米松优于单次地塞米松治疗；多次及单次地塞米松疗效均优于盐酸氨溴索治疗。     

氨溴索和糖皮质激素对胎鼠肺组织骨形态发生蛋白4表达的影响

目的 探讨产前给予氨溴索、糖皮质激素(地塞米松、倍他米松)对胎鼠肺组织骨形态发生蛋白4(BMP4)表达的影响.方法 18只孕鼠随机分成6组:对照组、氨溴索组、地塞米松1d组和3 d组,倍他米松1 d组和3 d组,每组3只.孕鼠妊娠第19天行剖宫产取胎仔肺组织,通过逆转录聚合酶链反应、免疫组化和免疫印记技术检测各组胎肺BMP4基因转录水平及蛋白表达差异.结果 BMP4 mRNA表达在地塞米松3 d组、倍他米松1、3 d组的表达均明显高于对照组(P<0.05),氨溴索组与地塞米松1 d组与对照组相比差异无统计学意义(P>0.05).免疫组化和免疫印记法结果显示,与对照组相比,地塞米松3 d组、倍他米松1 d组及3 d组BMP4表达量显著增加(P<0.01),而氨溴索组、地塞米松1 d组与对照组相比表达差异无统计学意义(P>0.05).结论 产前给予地塞米松、倍他米松均能显著促进胎肺组织BMP4的表达,提示糖皮质激素可能通过上调BMP4表达促进大鼠胎肺发育.     

盐酸氨溴索和倍他米松对大鼠胎肺形态发育影响的对比研究

目的 探讨产前注射盐酸氨溴索和倍他米松对大鼠胎肺形态发育的影响.方法 12只孕鼠随机分成4组:盐酸氨溴索组、倍他米松1d组、3d组及对照组,每组3只大鼠.盐酸氨溴索组、倍他米松3d组从妊娠第16天起分别腹腔注射3d盐酸氨溴索100mg/(kg·d)、倍他米松O.2mg/(kg·d);倍他米松1d组在妊娠第16、17天注射生理盐水,第18天注射倍他米松0.2mg/(kg·d);对照组在同样时间连续3d注射生理盐水.在妊娠第19天将孕鼠处死后立即剖腹取仔鼠,每只孕鼠取6只胎鼠肺组织,通过光镜观察、图像分析及电镜技术比较2种药物、不同疗程对孕鼠的胎仔肺组织形态结构影响.结果 光镜下各治疗组与对照组相比肺泡间隔薄(P<0.001),呼吸膜周径及肺泡表面积均增大(P相似文献   

维生素 D 缺乏对子代大鼠肺形态结构及血小板源性生长因子-A 表达的影响

目的：研究孕期维生素 D（VitD）缺乏对子代大鼠肺形态发育及血小板源性生长因子-A（PDGF-A）表达的影响。方法：雌性Sprague-Dawley (SD) 大鼠随机分为对照组、VitD 缺乏模型组（每组6只）。对照组正常饲养;模型组予以避光、不含 VitD 的饲料喂养,2周后与成熟 SD 雄性大鼠交配,每组取孕20 d的胎肺及生后1 d 新生鼠肺,光镜及电镜下观察肺形态结构, RT-PCR 及 Western blot 分别检测肺组织PDGF-A mRNA及蛋白水平的表达。结果：光镜下,模型组子鼠肺泡平均表面积、平均呼吸膜周径均小于对照组（P<0.05）,平均肺泡间隔厚度大于对照组（P<0.05）;电镜下,模型组子鼠的板层小体数量明显少于对照组,成熟细胞器较少见。RT-PCR 及 Western blot结果显示模型组子鼠肺组织PDGF-A mRNA和蛋白表达水平均低于对照组（P<0.05）。结论：孕期 VitD 缺乏抑制孕晚期胎鼠及新生大鼠的肺形态发育。VitD 缺乏能显著抑制肺组织 PDGF-A 表达;PDGF-A表达减低可能是VitD缺乏抑制大鼠肺发育的重要机制之一。     

盐酸氨溴索和地塞米松对胎鼠肺表面活性蛋白基因表达的影响

目的　探讨盐酸氨溴索和地塞米松对发育期胎鼠肺表面活性蛋白 (SPs)基因表达的影响。方法　将胎鼠 4 2只随机分为生理盐水对照组和盐酸氨溴索、地塞米松两个干预组 ,剖宫取孕19d的胎鼠肺组织作为早产鼠肺模型 ,用原位杂交研究胎鼠肺泡Ⅱ型上皮细胞内SP B基因的表达 ,逆转录PCR(RT PCR)观察分析各组肺表面活性蛋白SP A、SP B和SP CmRNA表达变化 ,用 β actinmRNA扩增产物为内参照密度扫描半定量分析。结果　 (1)发育 19d的胎鼠肺泡Ⅱ型上皮细胞内SP BmRNA表达阳性 ;(2 )鼠胚胎发育后期 ,支气管周围也分布着肺泡Ⅱ型上皮细胞 ;(3)生理盐水对照组SP A、SP B、SP CmRNA表达与 β actinmRNA比值分别为 0 81± 0 2 6、0 97± 0 2 0、0 88± 0 11。盐酸氨溴索干预SP A、SP B、SP CmRNA表达比值分别为 1 0 4± 0 16、1 2 8± 0 2 9、1 0 9± 0 2 5 ,与对照组比较显著性增加 (P <0 0 5 )。地塞米松干预后的胎鼠肺SP A、SP B、SP CmRNA表达比值分别为 1 0 8±0 2 5、1 2 3± 0 35、1 2 1± 0 2 5 ,与对照组比较显著性增加 (P <0 0 5 )。 (4 )对比盐酸氨溴索与地塞米松在促进SP A、SP B、SP C基因表达上 ,两者差异没有显著意义 (P >0 0 5 )。结论　盐酸氨溴索和地塞米松产前用药对发育期的胎鼠SPs基     

轻度维生素A缺乏对大鼠肺发育中肺组织血小板源性生长因子A表达的影响

目的 观察轻度维生素A缺乏(MVAD)对大鼠肺发育中血小板源性生长因子A(PDGF-A)表达的影响.方法 32只清洁级SD大鼠,雌雄各半.雌鼠随机分为MVAD组(n＝10)和对照组(n＝6).MVAD组喂养维生索A(VitA)缺乏饲料,对照组喂养正常饲料.3周后雌雄鼠交配,建立MVAD孕鼠模型.高效液相色谱法检测2组雌鼠血清VitA水平和孕20d胎鼠肝脏VitA水平;测量出生1d乳鼠身长、尾长、体质量;取MVAD组和对照组出生1d乳鼠肺组织,反转录(RT)-PCR方法检测出生1d乳鼠肺脏PDGF-A mRNA的表达,免疫组织化学方法检测其PDGF-A蛋白的表达水平.应用SPSS 13.0软件进行统计学分析.结果 MVAD组雌鼠毛色干枯,少食少动,孕鼠部分流产不孕.MVAD组雌鼠血清VitA水平显著低于对照组(P＜0.05).MVAD组孕20d胎鼠肝脏VitA水平亦显低于对照组(P＜0.05).MVAD组出生1d乳鼠身高、尾长及体质量数值均低于对照组(P,＜0.05).MVAD组出生1d乳鼠肺组织PDGF-A mRNA表达量显著低于对照组(P＜0.05);免疫组织化学检测出生1d乳鼠肺组织支气管上皮细胞、肺泡上皮细胞、血管内皮细胞内均可见PDGF-A蛋白表达,MVAD组PDGF-A蛋白表达量较对照组少(P＜0.05).结论 VitA在肺发育中起重要作用,MVAD引起PDGF-A的表达减少,可能是大鼠肺发育障碍的原因之一.     

地塞米松和倍他米松对大鼠胎肺骨形态发生蛋白信号转导的影响

目的：比较产前地塞米松、倍他米松给药对大鼠胎肺骨形态发生蛋白(BMP)信号转导通路的影响。方法：15只孕鼠随机分成5组：对照组、地塞米松治疗1 d组、3 d组和倍他米松治疗1 d组及3 d组。孕鼠妊娠第19天剖腹取胎鼠肺组织,通过RT-PCR、免疫组化和Western blot技术检测各组胎肺BMP4、BMP受体2（BMPR-II）、Smad1、转录活化因子2（ATF-2）基因转录及蛋白表达水平。结果：(1) BMP4 mRNA、BMPR-II mRNA、Smad1 mRNA的表达在倍他米松3 d组、1 d组及地塞米松3 d组均高于对照组(P＜0.05)。(2)免疫组化结果显示：与对照组相比,BMP4、BMPR-II、pSmad1、ATF-2在地塞米松3 d组、倍他米松1 d组及3 d组表达量显著增加(P＜0.01)。(3) Western blot检测显示与对照组相比,BMP4、BMPR-II蛋白在地塞米松3 d组及倍他米松1 d组、3 d组中表达丰富(P＜0.01)。结论：倍他米松、地塞米松可能参与调控大鼠胎肺BMP信号转导过程。对BMP信号转导分子BMP4、BMPR-II、Smad1表达的上调可能是其促胎肺成熟的重要机制之一。［中国当代儿科杂志,2010,12(11)：891-896］     

先天性膈疝肺动脉高压的实验研究

目的研究先天性膈疝（Congenital diaphragmatic hernia,CDH）肺发育不良中肺动脉高压（Dulmonary hypertension,PH）的量化指标,探讨血管内皮生长因子（vascular endothelial growth factor,VEGF）在CDH胎肺中的表达及在CDH肺动脉高压发生中的可能作用,探讨地塞米松（Dexamethasone,Dex）对VEGF和CDH肺发育的影响。方法采用Nitrofen诱导CDH模型胎鼠并分组：Dex组予以产前Dex治疗,CDH组未给予Dex,另取正常胎鼠为对照组。采用组织学测量、肺蛋白含量检测等方法,测定出平均肺泡面积、平均肺泡间隔厚度、每高倍视野肺血管数、动脉中膜厚度占外径比（MT％）、管壁面积占血管总面积比（WA％）、管腔面积占血管总面积比（LA％）、左肺与体重比、左肺蛋白含量与体重比等;实时荧光定量PCR（QPCR）和免疫蛋白印迹（Western blotting）方法检测各组胎肺中VEGF的表达及相对含量。结果与对照组相比,CDH组胎肺显著发育不良,包括肺微小动脉结构明显异常,表现为每高倍视野肺血管数减少、MT％增大、WA％增大,LA％减小（均P〈0．05）;另外VEGFmRNA及蛋白水平均明显升高（P〈0．05）。与CDH组相比,Dex组胎肺发育明显改善,表现为每高倍视野肺血管数增加、动脉中膜厚度占外径比减小、管腔面积占血管总面积比增大（均P〈0．05）;但VEGF mRNA及蛋白水平未发现明显变化（P〉0．05）。结论VEGF在CDH胎肺中的表达增高可能是CDH肺发育不良形成机制之一;产前地塞米松治疗可明显改善肺微小动脉结构异常及肺发育不良,但未发现对VEGF的表达有影响,提示Dex可能并非通过调节VEGF的表达而发挥改善肺动脉高压及肺发育不良的作用。     

地塞米松对先天性膈疝胎鼠肺发育的影响

目的研究地塞米松对先天性膈疝(Congenital Diaphragmatic Hernia,CDH)胎鼠肺发育的影响,并探讨其可能机制。方法采用Nitrofen法制作胎鼠CDH模型并分组,地塞米松组予以产前地塞米松治疗,Nitrofen组则不予地塞米松治疗,另取正常胎鼠为对照组;采用组织学检查方法评价肺发育情况,免疫组化和图像分析方法检测地塞米松作用前后胰岛素样生长因子-Ⅰ(Insulin-like Growth Factor,IGF-Ⅰ)在胎肺中的表达及相对含量。结果与Nitrofen组相比,地塞米松组肺组织中IGF-Ⅰ的表达明显降低,且肺组织发育明显改善。结论胎儿期地塞米松通过下调肺组织中IGF-Ⅰ的表达,来改善肺组织的发育。     

不同剂量多疗程地塞米松对早产大鼠肺WNT信号转导途径的影响

目的 探讨产前孕鼠应用不同剂量多疗程地塞米松对早产大鼠肺WNT信号转导途径的影响.方法 孕SD大鼠12只随机分为对照组、地塞米松小剂量组和地塞米松大剂量组,每组4只.于孕第16、17、18天,连续3 d腹腔注射药物.对照组予9 g/L盐水;地塞米松小剂量组予地塞米松0.4 ms/(ks·d);地塞米松大剂量组予地塞米松0.8 mg/(kg·d),均用9 g/L盐水稀释至0.5 mL.取孕19 d胎鼠肺组织,RT-PCR法检测WNT信号转导途径中WNT7b、WNT5a、WNT2、糖原合成酶-3β(GSK-3β)、β-连环蛋白(β-cate-nin)基因mRNA的表达.结果 地塞米松小剂量及大剂量组胎肺WNT7b(0.55±0.19、0.64±0.54)及β-catenin基因mRNA的表达量(2.03±0.58、2.40±0.89)均显著高于对照组(WNTTb:0.18±0.10,β-catenin:1.77±0.54)(Pa<0.01),WNT5a mRNA(0.57±0.26、1.13±0.53)和GSK-3β基因mRNA(1.04±0.46、1.09±0.56)表达量均显著低于对照组(WNT5a:1.48±0.70,GSK-3β:2.22±1.02)(P<0.05,0.01),WNT2的表达量与对照组相比差异无统计学意义.结论 产前给予地塞米松影响胎肺WNT7b、WNT5a、β-catenin及GSK-3β基因的表达,可能通过引起WNT信号转导途径障碍导致胎肺形态发育异常,造成胎肺功能缺陷.     

Responses of pulmonary platelet-derived growth factor peptides and receptors to hyperoxia and nitric oxide in piglet lungs

The peptides platelet-derived growth factor-A (PDGF-A) and especially -B have important roles in lung development. The effect of hyperoxic exposure with and without inhaled nitric oxide (iNO) on lung expression of PDGF and its receptors is unknown. We hypothesized that hyperoxia exposure would suppress mRNA expression and protein production of these ligands and their receptors. The addition of iNO to hyperoxia may further aggravate the effects of hyperoxia. Thirteen-day-old piglets were randomized to breathe 1) room air (RA); 2) 0.96 fraction of inspired oxygen (O2), or 3) 0.96 fraction of inspired oxygen plus 50 ppm of NO (O2+NO), for 5 d. Lungs were preserved for mRNA, Western immunoblot, and immunohistochemical analyses for PDGF-A and -B and their receptors PDGFR-alpha and -beta. PDGF-B mRNA expression was greater than that of PDGF-A or PDGFR-alpha and -beta in RA piglet lungs (p<0.05). Hyperoxia with or without iNO reduced lung PDGF-B mRNA and protein expression relative to the RA group lungs (p<0.01). PDGF-B immunostain intensity was significantly increased in the alveolar macrophages, which were present in greater numbers in the hyperoxia-exposed piglet lungs, with or without NO (p<0.01). PDGFR-beta immunostaining was significantly increased in airway epithelial cells in O2- and O2+NO-exposed piglets. PDGF-A and PDGFR-alpha immunostain intensity and distribution pattern were unchanged relative to the RA group. Sublethal hyperoxia decreases PDGF-B mRNA and protein expression but not PDGF-A or their receptors in piglet lungs. iNO neither aggravates nor ameliorates this effect.     

Retinoic acid fails to reverse oligohydramnios-induced pulmonary hypoplasia in fetal rats

All-trans retinoic acid (ATRA) stimulates platelet-derived growth factor (PDGF)-A expression and enhances alveolarization in rat lungs. On d 16 of gestation, pregnant Sprague-Dawley rats were randomly assigned to either a retinoic acid group (intragastric ATRA at 10 mg/kg body weight) or a vehicle group. We punctured each amniotic sac, and fetuses in the opposite uterine horn served as controls. On d 21 of gestation, the fetuses were delivered by cesarean section. Rats subjected to oligohydramnios exhibited significantly lower lung weights and lung/body weight ratios, and ATRA had no effects on the body or lung weights of oligohydramnios-exposed rats. Lung PDGF-A and -B mRNA expression was significantly lower in oligohydramnios-exposed rats compared with control littermates of maternal vehicle-treated dams. Maternal retinoic acid treatment significantly increased PDGF-A and -B mRNA expression in control and oligohydramnios-exposed rats compared with all rats and oligohydramnios-exposed rats of maternal vehicle-treated dams, respectively. Rats exposed to oligohydramnios exhibited a significantly lower generation of alveolar saccules than did control rats in the maternal retinoic acid- and vehicle-treated groups. In this model, maternal retinoic acid treatment showed no positive effects on oligohydramnios-induced pulmonary hypoplasia in the pseudoglandular stage.     

High-dose vascular endothelial growth factor increases surfactant protein gene expressions in preterm rat lung

AIMS: To investigate the effects of intra-amniotic vascular endothelial growth factor (VEGF) treatment on surfactant pool sizes and surfactant protein (SP) gene expressions in fetal rat lung. METHOD: On the 18th day of gestation, an abdominal midline incision was performed on timed pregnant Sprague-Dawley rats and the two uterine horns were exposed. VEGF (2.5 microg or 5.0 microg) and saline were injected into the amniotic cavity of the left and right uterine horns, respectively. On the 19th day of gestation, fetuses were delivered by caesarean section. RESULTS: We analyzed the data between the fetuses within the same dam in each group. Mean fetal body weight and lung tissue saturated phosphatidylcholine and total phospholipids were comparable between control and VEGF-treated rats at each VEGF dosage. Lung SP mRNA expressions were comparable between control and VEGF 2.5 microg-treated rats. VEGF 5.0 microg treatment increased lung SP mRNA expressions and the values were statistically significant for SP-B and SP-D mRNAs when compared with the control rats. CONCLUSIONS: These results suggest that VEGF might have potential therapeutic implications in enhancing fetal lung maturation.     

地塞米松对高氧肺损伤新生大鼠肺水通道蛋白1表达的影响

目的 探讨地塞米松对新生大鼠高氧肺损伤时水通道蛋白1(AQP1)表达的影响及其对肺损伤的可能保护机制.方法 新生Wistar大鼠32只随机分为空气组、高氧组、空气+地塞米松组、高氧+地塞米松组.第3天取肺组织,采用逆转录-聚合酶链反应(RT-PCR)和免疫组织化学法检测AQP1的mRNA表达和分布变化;并对肺湿/干重比(W/D)、支气管肺泡灌洗液(BALF)中的蛋白含量、肺通透指数及组织病理学改变进行对比分析.结果 高氧暴露第3天肺组织出现出血、炎性细胞浸润和水肿,肺W/D、BALF蛋白含量、肺通透指数明显升高;地塞米松干预组肺损伤程度减轻,测定值降低.空气组、高氧组、高氧+地塞米松组AQP1 mRNA相对吸光度比值分别为0.70±0.04、0.42±0.03、1.04±0.04,各组间差异有显著性(P<0.05);与空气组相比,高氧组AQP1 mRNA表达明显降低,高氧+地塞米松组AQP1 mRNA表达显著上调;AQP1蛋白表达与其mRNA变化一致.结论 高氧肺损伤时大鼠肺AQP1表达下调;地塞米松干预对肺损伤有保护作用,上调肺AQP1的表达可能是其作用机制之一.     

Leptin enhances lung maturity in the fetal rat

Pulmonary alveolar type II cells synthesize and secrete phospholipids and surfactant proteins. In most mammalian species, the synthesis of phospholipids and proteins of lung surfactant increases with fetal lung maturation, which occurs late in gestation. Factors that may promote lung maturation and surfactant production include the placental hormone, leptin, whose expression increases with advancing gestational age. We demonstrate that physiologic concentrations of leptin (1 and 10 ng/mL) increase the levels of surfactant proteins (SP) A, B, and C mRNA as well as SP-A and SP-B protein in d-17 fetal rat lung explants in vitro. To determine whether leptin exerts similar effects in vivo, we administered leptin antenatally to pregnant rats and compared its effects to that of dexamethasone, a known mediator of fetal lung development. Antenatal treatment with leptin for 2 d significantly increased the average weight of the fetal lungs in relation to their body weight. Histologic analysis revealed that the increase in fetal lung weight was accompanied by an increase in the number and maturation of type II alveolar cells and the expression of surfactant proteins B and C in these cells. Collectively, these results suggest that leptin is a cytokine regulator of rat fetal lung maturity.     

地塞米松对大鼠胎肺形态结构及Wnt信号转导途径的影响

目的 比较产前给予不同剂量地塞米松对大鼠胎肺形态结构及Wnt信号转导途径的影响.方法 孕鼠12只,于孕16、17、18 d,连续3 d给孕鼠腹腔注射药物,随机分为3组,每组4只.地塞米松小剂量组：地塞米松0.4 mg/(kg·d),地塞米松大剂量组：地塞米松0.8 mg/(kg·d),均用生理盐水稀释至0.5ml;对照组：生理盐水0.5 ml/d;取孕19 d胎鼠肺组织,HE染色观察肺病理学改变;RT-PCR、Western-Blot方法检测Wnt信号转导途径中Wnt7b、GSK-3β、β-catenin基因mRNA和蛋白表达.结果 (1)肺脏病理学改变：HE染色可见：地塞米松小剂量组肺泡数目为(15.6±2.1)个;大剂量组(13.2±1.6)个,对照组(20.8±2.0)个;肺泡间隔厚度：地塞米松小剂量组(11±5)μm;大剂量组(11±4)μm;对照组(13±7)μm;肺泡腔结构：地塞米松小剂量组(2483 ±1336)μm2;大剂量组(2924 ±1705)μm2;对照组(1913±764)μm2;以上各指标地塞米松组与对照组差异均有统计学意义(P均＜0.01),地塞米松大剂量组较小剂量组肺泡数目明显减少(P＜0.01).(2)地塞米松组胎肺Wnt7b及β-catenin基因mRNA的表达量均高于对照组,GSK-3β表达量低于对照组(1.1±0.6)(P均＜0.05);地塞米松组胞浆GSK-3β蛋白表达量低于对照组,大剂量组低于小剂量组;地塞米松小剂量组胞浆β-catenin的表达高于对照组,大剂量组低于对照组;胞核β-catenin蛋白表达量高于对照组.结论 产前使用地塞米松,肺泡数目减少,肺泡腔结构变大,肺泡间隔厚度变薄,周围结缔组织减少,影响胎肺形态发育;Wnt7b、β-catenin和GSK-3β基因表达异常;胎肺形态发育异常可能是通过地塞米松所致的Wnt信号转导途径障碍而发生.