CT一1C末端多肽对昆明小鼠心肌肌小节α-Actin、α-Actinin及UCP2表达的影响

目的：观察心脏营养素一1（CT一1）慢性作用所诱导的小鼠重构心肌中,肌小节收缩性蛋白a—Ac—tin、细胞骨架蛋白d—Actinin及线粒体解偶联蛋白2（uCP。）的表达情况。方法：实验组昆明小鼠腹腔注射CT一1C末端肽（carboxy—terminalpolypeptideofcardiotrophin-1,CT一1一CP）1、2、3、4周（每组10只,雌雄各半）后,对照组小鼠（10只,雌雄各半）腹腔注射生理盐水4周后,摘取小鼠心脏标本,石蜡包埋,切5／,m厚切片,采用SABC检测肌小节结构蛋白d—Actin、a—Actinin与UCP2在小鼠心肌中的表达情况;同时采用Westernblot检测小鼠心肌组织中3种蛋白质的相对表达量。结果：免疫组化结果显示,a—Actin的阳性颗粒主要集中于细胞核的周围,a—Aetinin则趋于向肌节的横纹处汇聚,而UCP。则较均匀地散布于肌细胞浆中。结合Westernblot相对灰度的比较分析,在对照组,a—Actin的表达水平略高于d—Actinin和UCP2,但3者之间并无明显的差异（WB：F=0．249,P〉0．05）。注射CT—l—CP后,a—Actin的表达基本呈逐渐减弱的趋势,但对照组与4个注射组之间并无明显差异（x2=7．386,P〉0．05）;与之相反,a-Actinin的表达则呈逐渐增强的趋势,阳性细胞数的百分比和阳性颗粒的染色强度都逐渐增多,而且各组间呈现出明显差异（x2=21．977,P〈0．01）;UCP。的表达则在1周后增强,2周后达最高值,随后出现降低,4周后降至接近对照组的水平。结论：CT一1一CP的慢性作用可导致肌小节不同结构蛋白的比例发生改变,a—Actin的表达减少,Q—Aetinin的表达增多;而线粒体UCP：的表达达到一定峰值后即开始降低。     

A Novel Technique for the Preparation of ~（125）I-5-trimethylstannyl-1-（2-deoxy-2-fluoro-beta-D-arabino-furanosyl） Urail and Its Biodistribution Pattern in Kunming Mice

In this study, a novel technique for the preparation of 125I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FIAU) was developed, 125I-FIAU biodistribution profile was detected in Kunming mice and the possibility of using FTAU radio-labeling for reporter gene imaging was explored. 5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FTAU) was labeled with radioiodine (125I). A rotary evaporation method was used to remove excess methanol. The reactant was purified through a Sep-Pak C18 reversal phase column. The radiochemical purity and in vivo stability were determined using silica gel thin layer chromatography (TLC). The biodistribution of 125I-FIAU in Kunming mice was also detected. The results showed that 125I-FIAU could be radiolabeled effectively with FTAU, with mean labeling rate being (81±0.38)% (n =5). The mean radiochemical purity of (98.01±0.40)% (n=5) was achieved after a reversal phase Sep-park column purification. 125I-FIAU was stable when incubated in normal human serum or in saline at 37°C, with a radiochemical purity >96% during a 0.5-24 h time period. Biological experiments exhibited rapid clearance of 125I-FIAU from the blood pool. 125I-FIAU was mostly excreted by kidneys. 125I-FIAU in myocardium dropped conspicuously after 8 h and there was hardly retention at 24 h. We were led to concluded that the new method of radioiodinization of FTAU for the preparation of 125I-FIAU is easy, highly effective and stable in vivo. The biodistribution of 125I-FIAU in Kunming mice showed it can serve as an imaging probe for myocardial reporter genes.