Wistar大鼠增龄过程中某些心源性肽类激素的变化

ALTERATION OF RAT MYOCARDIAL PEPTIDE HORMONES WITH INCREASING AGE

选用体重为50～586g的雌性Wistar大鼠41只分为5组(1,3,6,10,21月龄),21月龄组为老龄组。制备心肌组织匀浆,应用放射免疫方法测定不同部位免疫活性的心肌局部Ang Ⅰ、Ⅱ和心室ANF。制备心肌组织切片,应用免疫组织化学方法检测Ang Ⅱ和ANF。结果表明:心房AngⅡ和ANF明显高于心室;心肌局部AngⅡ主要存在于心肌细胞浆中;心肌局部Ang Ⅰ与AngⅡ呈显著性正相关;各月龄组心肌局部Ang Ⅰ、Ⅱ和心室间隔ANF含量差异有显著性,与月龄呈负相关,21月龄组心肌局部AngⅡ下降幅度最明显,左、右心室AngⅡ比左、右心房下降更明显。本实验提示,随年龄增加,心脏老化发展,心脏某些重要的内分泌功能(肽类激素)逐渐减退,心室内分泌功能减退更明显。

The process of aging can induce major alterations in structure and function of myocardium. 41 female Wistar rats-weighing 50-586 g were divided into 5 groups (1,3, 6,10, 21 mo.). The 21-month group was taken as aged rats. Myo-cardial homogenates (W/V= 1 g/10 ml) were prepared. The local myocardial immunoreactive Ang I, II and the ventricular ANF levels in different parts of the myocardium were measured by sensitive RIA. The sections of the myocardial tissue were prepared. The local Ang II and ANF were measured by immunohistochemistry. The results showed that auricular Ang II and ANF is markedly higher than the ventricular ones. Local myocardial Ang II is for the most part present in the cytoplasm. There is a positive correlation between the local Ang I and Ang II levels. There are significant differences in levels of Ang I, Ang II and interventricular septum ANF between various age groups. There is a perfect negait ve correlation between levels of Ang as well as ANF and the age in months. The reduction in local Ang II level is most striking in the 21-month group. The reduction of local Ang II level in the ventricles exceeds that in the atria. The experiment suggested that as age increases, some important hormonal functions of the heart gradually weaken; such a change is most noticeable in the ventricles.