Morphometric Study of Early Postnatal Development in the Left and Right Ventricular Myocardium of the Rat: II. Tissue Composition, Capillary Growth, and Sarcoplasmic Alterations
Morphometric Study of Early Postnatal Development in the Left and Right Ventricular Myocardium of the Rat: II. Tissue Composition, Capillary Growth, and Sarcoplasmic Alterations
复制标题
大鼠左右心室心肌产后早期发育的形态测量研究：II．
作者：
G. Olivetti;P. Anversa;A. Loud
出生后1 ~ 5天和5 ~ 11天，用形态计量学方法测量左（L）和右（R）心室游离壁毛细血管网和肌细胞胞质成分的绝对和差异生长。从第1天到第11天，每个心室的毛细血管长度、管腔体积、管腔表面积和内皮细胞体积的增加速度均比心肌质量或肌细胞质量快2-3倍。平均毛细血管间距和平均毛细血管横截面积明显减小。穿过心室壁的平均毛细血管数从16增加到79（L）和14增加到22（R）。1 - 11天左右心室肌细胞的细胞质成熟包括肌原纤维（1.2倍）、线粒体（1.8倍）和滑面内质网（2.1倍）的体积百分比增加，以及平均线粒体大小[1.9倍（L），1.2倍（R）]和每个细胞数量[2.7倍（L），3.6倍（R）]增加。尽管总体左心室生长增加了2倍，但在1天和11天时，两个心室的心肌成分几乎无法区分。然而，亚细胞和微血管的变化，通常更快地实现在左心室从1至5日龄，表现出许多结构差异和滞后的发展，在右心室在5日龄。因此，出生后不久，左心室和右心室的工作要求改变的出生后心肌适应导致的形态学变化，可能是一个短暂的差异心室功能在约5天的年龄的基础。《循环研究》46：503-512，19 S 0
The absolute and differential growths of the capillary network and of myocyte cytoplasmic components in the left (L) and right (R) ventricular free walls were measured morphometrically from 1 to 5 days and from 5 to 11 days after birth. From 1 to 11 days, capillary length, luminal volume, luminal surface area, and endothelial cell volume each increased 2-3 times more rapidly than myocardial mass or myocyte mass in each ventricle. Mean intercapillary distance and the transverse crosssectional area of the average capillary decreased markedly. The mean number of capillaries across the ventricular walls increased from 16 to 79 (L) and 14 to 22 (R). Maturation of the cytoplasm of left and right ventricular myocytes from 1 to 11 days included increases in the volume percentage of myofibrils(1.2-fold), mitochondria (1.8-fold), and smooth endoplasmic reticulum (2.1-fold) and increases in mean mitochondrial size [1.9-fold (L), 1.2-fold (R)] and number per cell [2.7-fold (L), 3.6-fold (R)]. Despite a 2-fold greater overall left ventricular growth, the myocardial compositions of both ventricles were nearly indistinguishable at 1 and 11 days. Both subcellular and microvascular changes, however, were generally achieved more rapidly in the left ventricle from 1 to 5 days of age, demonstrating many structural differences and a lagging development in the right ventricle at 5 days. Thus, postnatal myocardial adaptation to the altered work demands on the left and right ventricles shortly after birth resulted in morphological changes that could be the basis for a transient disparity in ventricular functions at about 5 days of age. Circ Res 46: 503-512, 19S0