联合应用生长激素和谷氨酰胺对短肠大鼠小肠粘膜IGF-1 mRNA表达的影响

选用 4 0只手术成功的SD短肠大鼠 ,按 2× 2析因实验设计随机分为 4组 ,分别给予常规全肠外营养 (TPN组 ,n =10 )、附加谷氨酰胺 (TPN +Gln组 ,n =10 )、附加生长激素 (TPN +GH组 ,n =10 )及附加谷氨酰胺和生长激素全肠外营养 (TPN +Gln +GH组 ,n =10 ) ,持续 6天 ,取 8只正常大鼠模拟手术后第 1天处死 ,作为基础对照组 (n =8)。应用放免分析法检测血生长激素和血IGF 1的水平 ,Northernblot方法检测残留小肠粘膜IGF 1mRNA表达。探讨了联合应用生长激素和谷氨酰胺防止小肠粘膜萎缩的可能分子机制。结果表明 ,GH组和GG组血浆GH和IGF 1水平较TPN和TPN +Gln组明显增高 (P <0 .0 1) ;TPN组小肠粘膜组织IGF 1mRNA表达明显低于对照组 (P <0 .0 1) ,TPN+Gln组和TPN +GH组小肠粘膜IGF 1mRNA的表达较TPN组明显增高 ;TPN +Gln +GH组小肠粘膜组织IGF 1mR NA的表达水平提高显著 ,高于TPN +GH组和TPN +Gln组 (P <0 .0 1)。这说明 ,生长激素和谷氨酰胺的联合应用可能通过上调小肠粘膜细胞IGF 1mRNA的表达 ,增加IGF 1的自分泌和旁分泌 ,发挥其促进细胞分裂增殖和抑制细胞凋亡作用 ,从而防止小肠粘膜萎缩的发生。

低氧和运动经AR-IGF-1对骨骼肌蛋白质合成的作用

目的:探讨低氧、运动对骨骼肌蛋白质合成的作用。方法:2月龄雄性SD大鼠40只随机分为对照组、低氧组、运动组、低氧运动组,实验28天后取材测试。结果:(1)运动组AR蛋白表达量、AR活性与骨骼肌总蛋白质含量比对照组显著升高;(2)低氧组骨骼肌睾酮含量、AR蛋白表达量、IGF-1mRNA含量以及肌纤维横截面积较对照组显著降低;AR活性、骨骼肌蛋白质含量较对照组显著升高;(3)低氧运动组AR蛋白表达量、AR活性和骨骼肌总蛋白含量比运动组显著下降。结论:(1)运动后进行低氧暴露比单纯运动更能通过AR含量-AR活性水平抑制蛋白质合成;(2)低氧、运动或低氧运动通过睾酮调节AR数量及活性,最终影响骨骼肌蛋白含量;(3)低氧、运动或低氧运动可通过调节AR转录活性影响IGF-1mRNA表达,最终调节骨骼肌蛋白质合成。

IGF-1 mRNA expression of adult rat thyroid cell cultured in vitro

Objective: To investigate the law of age-related changes of insulin-like growth factor-1 (IGF-1) expression of rat thyroid cells cultured in vitro. Methods: Rat thyroid of different age (10, 45, 65, 100, 150 weeks) was isolated and thyrocytes cultured. Total RNA was extracted in different rat age group when thyroid cells had been cultured for two weeks. mRNA IGF-1 expression was measured with reverse-transcription polymerase chain reaction( RT-PCR) in each group and compared. Results: Quantity of total RNA in thyroid cells decreased with ageing when the rat thyroid cells had been cultured for 2 weeks. There is significant difference among groups (P<0.05). Expression of IGF-1 mRNA could be detected in thyroid cells of different age cultured in vitro. Quantity of IGF-1 mRNA expression by RT-PCR analysis increased from 10 to 45 weeks old, and then decreased with ageing. Conclusion: Rat thyroid cells from different age cultured in vitro can express IGF-1 mRNA. Quantity of total RNA in thyroid cells cultured in vitro decreased with aging. IGF-1 mRNA expression was correlated to age (r=0.401, P<0.05).

人重组胰岛素样生长因子-1对糖尿病大鼠肾脏的影响

目的 观察人重组胰岛素样生长因子 1(rhIGF 1)对糖尿病大鼠肾脏的影响。方法 采用生化法、放射免疫法及逆转录 聚合酶链反应 (RT PCR)技术等方法。结果 (1)糖尿病治疗组 2 4h尿白蛋白排泄率和尿量低于糖尿病对照组 ;(2 )糖尿病对照组血清IGF 1含量、肾组织IGF 1含量及IGF 1信使核糖核酸 (IGF 1mR NA)表达明显低于正常对照组 ;糖尿病治疗组血清IGF 1含量明显高于糖尿病对照组 ,肾组织IGF 1含量及IGF 1mRNA表达与糖尿病对照组无明显差异 ;(3)糖尿病对照组血清生长激素 (GH)高于正常对照组 ,糖尿病治疗组血清GH低于糖尿病对照组 ;(4)电镜观察大鼠肾脏病理切片发现rhIGF 1对糖尿病大鼠肾脏损害有改善作用。结论 小剂量外源性rhIGF 1不会加重糖尿病肾脏的损害。

Study on Mechanism of Dendrobium officinale Kimura et Migo in Preventing and Treating Exercise-induced Muscle Damage(EIMD)in Rats

[Objectives]This study was conducted to observe the mechanism of Dendrobium officinale Kimura et Migo on gastrocnemius muscle in rats with exercise-induced muscle damage(EIMD).[Methods]The micro-injury model of skeletal muscle was established by treadmill training.Forty two SD rats were randomly divided into a control group,1,12 and 24 h exercise groups,D.officinale 2 ml+1 h exercise group,D.officinale 2 ml+12 h exercise group,and D.officinale 2 ml+24 h exercise group,with 6 rats in each group.Various D.officinale groups were given the drug once in the morning and once in the evening at a dose of 2 ml/time,a week in advance.Except for the quiet group,the samples were collected from the 1,12 and 24 h exercise groups after anesthesia following 1,12 and 24 h of exercise for the last time,respectively,and the D.officinale 2 ml+1 h exercise group,D.officinale 2 ml+12 h exercise group and D.officinale 2 ml+24 h exercise group were also sampled after anesthesia following 1,12 and 24 h of exercise for the last time,respectively.The contents of ATP,CK-MM and CK in rat serum were determined by enzyme-linked immunosorbent assay(ELISA).The histopathological changes of gastrocnemius muscle were observed by HE staining.PCR and Western-blot detection were carried out to analyze the effects of D.officinale on IGF-1 mRNA and protein expression in gastrocnemius muscle.[Results]Compared with the quiet group,the ATP contents in the serum of rats in the 1,12 and 24 h exercise groups significantly decreased(P<0.01),while the CK and CK-MM contents significantly increased(P<0.01).The expression of IGF-1 mRNA and protein in the gastrocnemius muscle tissue significantly increased(P<0.01).Compared with the 1 h exercise group,the ATP content and IGF-1 protein expression in the gastrocnemius muscle tissue of the D.officinale liquid+1 h exercise group significantly increased(P<0.05),while the CK and CK-MM contents significantly decreased(P<0.01).Compared with the 12 h exercise group,the D.officinale liquid+12 h exercise group showed a significant increase in ATP content(P<0.01),significant increases in IGF-1 mRNA and protein expression in the gastrocnemius muscle tissue(P<0.01),and significant decreases in CK and CK-MM contents(P<0.01).Compared with the 24 h exercise group,the ATP content and IGF-1 mRNA and protein expression in the gastrocnemius muscle tissue of the D.officinale liquid+24 h exercise group significantly increased(P<0.01),while the CK and CK-MM contents significantly decreased(P<0.01).From the pathological tissue morphology of the gastrocnemius muscle in rats with EIMD treated with D.officinale,it could be concluded that the gastrocnemius muscle of each exercise group was significantly damaged,and the damage was significantly alleviated after administration of D.officinale liquid.[Conclusions]The effects and mechanism of D.officinale on prevention and treatment of EIMD in rats might be related to the promotion of IGF-1 mRNA and protein expression in injured tissues by reducing ATP energy consumption,CK-MM and CK activity.

胰岛素样生长因子-1与胎儿生长发育关系的研究

胎儿宫内的生长发育受多种因素影响，包括遗传、营养、生长激素及环境等方面。尽管进行了广泛的研究，胎儿生长发育中起重要作用的内分泌机制仍未完全阐明。胰岛素样生长因子-1（insulin-likegrowthfactor-1，IGF-1）是由70个氨基酸组成的单链碱性蛋白，具有胰岛素样生物活性，参与糖、脂肪、蛋白质的代谢，并可促进细胞增殖分化，抑制细胞凋亡。近年来研究发现IGF-1是妊娠早期胚胎发育的重要调节因子之一，并推测其可能参与妊娠中晚期胎儿生长发育的调节。本研究通过对母体血清中IGF-1的含量、胎儿脐血以及胎盘组织中IGF-1mRNA和蛋白的表达量进行测定，以进一步探讨IGF-1与胎儿生长发育的关系。