婴儿室间隔缺损合并肺动脉高压心房肌Ⅰ、Ⅲ型胶原的表达改变

Expression of Type Ⅰand Ⅲ Collagen in Atrium of Ventricular Septal Defect with Pulmonary Hypertension in Infants

[目的]探讨室间隔缺损合并肺动脉高压婴儿心房肌Ⅰ、Ⅲ胶原蛋白含量的变化,并分析心肌间质胶原成分含量及比值的改变与肺动脉压力的相关性.[方法]试验组为30例室间隔缺损合并肺动脉高压婴儿,体外循环建立时留取少量右心房肌标本,对照组为8例非心血管疾病及胶原疾病死亡的儿童,尸体解剖时留取右心房肌,并应用免疫组化及数字图像分析技术观测其心房肌Ⅰ、Ⅲ胶原的表达.[结果]正常心房肌Ⅰ型胶原为粗、细不等的条状纤维,彼此连接成网,Ⅲ型胶原呈散在的斑片状分布,而婴儿室间隔缺损合并肺动脉高压患儿Ⅰ型胶原呈现出大斑片状增加,Ⅲ胶原呈现出条索状增加.免疫组化图像分析显示：对照组Ⅰ型胶原含量明显高于Ⅲ型胶原,有显著差异（P〈0.01）,Ⅰ型/Ⅲ型比值为5.66±0.43,试验组中：Ⅰ型和Ⅲ型胶原含量均较对照组显著增加（P〈0.01）,Ⅰ型/Ⅲ型比值为3.04±2.06,Ⅲ型胶原蛋白增加幅度较大,Ⅰ型/Ⅲ型比值较前明显减少.线性回归模型拟合显示肺动脉压力与Ⅰ型/Ⅲ型呈显著相关,肺动脉压力=0.927-0.058（Ⅰ/Ⅲ）.[结论]室间隔缺损合并肺动脉高压婴儿心房肌中,Ⅰ型及Ⅲ型胶原含量均较正常心房肌中明显增加,且以Ⅲ型胶原含量增加明显,表明室间隔缺损合并肺动脉高压婴儿未成熟心肌组织亦存在心肌间质重构.室间隔缺损合并肺动脉压力患儿中,肺动脉压力与Ⅰ型及Ⅲ型胶原含量之比（Ⅰ/Ⅲ值）呈线性关系,即：肺动脉压力=0.927～0.058（Ⅰ/Ⅲ）,表明随着肺动脉压力的增高,心肌间质重构将逐步加重.

[Objective] To explore the changes of type Ⅰ and Ⅲ collagen content in the atrium of ventricular septal defect （VSD） with pulmonary hypertension（PH） in infants and analyze the correlation between the changes and ratio of myocardial interstitial collagen contents and pulmonary artery pressure. [Methods] The specimens of a little of right atrium in 30 cases of VSD with PH in the experiment group were obtained at the beginning of cardiopulmonary bypass（CPB）. The specimens of right atrium in 8 death children without non-cardiovascular disease or collagen disease in control group were obtained when autopsy. Immunohistochemistry method and digital image analysis were used to observe the expression of type Ⅰ and Ⅲ collagen in atrium. [Results] In the normal atrium, type I collagen fibers was stripped fiber with different thickness and connected into network each other, and type Ⅲ collagen distributed sporadically and was patching. In the atrium of VSD with PH, type Ⅰ collagen fibers increased as patching and type Ⅲ collage fibers increased as stripped. Immunohistochemistry and digital image analysis showed that type I collagen content in control group was obviously higher than type Ⅲ collagen content, and there was significant difference（ P 〈0.01）. The ratio of type I to type Ⅲ collagen in control group was 5.66±0.43. Type Ⅰ and Ⅲ collagen contents in experiment group increased more markedIy than those in control group（ P 〈0.01）, and the ratio of type Ⅰ to type Ⅲ collagen was 3.04±2.06. Type Ⅲ collagen in experiment group increased more significantly, and the ratio of type Ⅰ to type Ⅲ collagen decreased obviously. The fitting of linear regression model showed that there was significant correlation between pulmonary artery pressure and the ratio of type Ⅰ to type Ⅲ collagen. Pulmonary artery pressure was 0. 927± 0. 058（ Ⅰ / Ⅲ ）. [Conclusion] Compared with normal atrium, the contents of type Ⅰ and Ⅲ collagen in atrium of VSD with PH in infants increase significantly and the content of type Ⅲ collagen increases more obviously. It indicates that the immature myocardium of VSD with PH also has myocardial interstitial remodeling. There is linear correlation between pulmonary artery pressure and the ratio of type Ⅰ to type Ⅲ collagen. Pulmonary artery pressure was 0. 927-0. 058 （ I/Ⅲ ）. Myocardial interstitial remodeling gradually aggravates with the increasing of pulmonary artery pressure.