Mandarim-de-Lacerda C A, de Souza R M
Department of Anatomy, State University of Rio de Janeiro, Brazil.
Ital J Anat Embryol. 1994 Jan-Mar;99(1):43-55.
The relative growth of the myocardium was studied in the postsomite embryos (Carnegie stages 13 to 23) of 54 rats (Rattus norvegicus). Cavalieri's principle was applied to determine the myocardial volume of each rat heart. The calculated volume was related to the corresponding body weight and crown-rump length using a bivariate allometric equation. The resulting scattergram proved to be discontinuous: the rate of myocardial growth in the postsomite embryo was represented by two distinct phases. The first, from stages 13 to 20, was allometrically-negative; the second, from stages 21 to 23, allometrically-positive. This difference in myocardial growth rate might have been due in part to the functional increase of circulatory flow in the peripheral vascular bed in response to the demand for increased cardiac output that occurs at the conclusion of the embryonic period.
对54只大鼠（褐家鼠）的体节后胚胎（卡内基分期13至23期）的心肌相对生长进行了研究。应用卡瓦列里原理确定每只大鼠心脏的心肌体积。使用双变量异速生长方程将计算出的体积与相应的体重和冠臀长相关联。所得散点图证明是不连续的：体节后胚胎中心肌生长速率由两个不同阶段表示。第一个阶段，从13期到20期，是异速生长为负；第二个阶段，从21期到23期，是异速生长为正。心肌生长速率的这种差异可能部分归因于胚胎期结束时外周血管床循环血流量的功能性增加，以应对心输出量增加的需求。
