Mall G, Zimmer G, Baden S, Mattfeldt T
Pathologisches Institut, Universität Heidelberg, FRG.
Basic Res Cardiol. 1990 Nov-Dec;85(6):531-40. doi: 10.1007/BF01907888.
Stereological investigations on myocardial capillaries provided evidence that the common estimator of capillarity, the capillary density (i.e., number of capillary profiles per unit transverse sectional area), underestimates the true capillary supply since the capillary axes are not oriented perfectly in parallel to the myofiber axes. Recently, we studied the "true" capillarity, i.e., the length density of capillaries (LV = capillary length per capillary volume), in some experimental models of cardiac hypertrophy which have been published elsewhere. It has been shown that LV decreases in renovascular hypertension, but is maintained in physical exercise and after chronic thyroxin application. However, the growth pattern of capillaries in hypertrophic hearts has not yet been analyzed. In the present paper it is demonstrated that important information on the capillary network can be derived from the two-dimensional capillary-to-fiber ratios (2D CFR: capillary profiles per myofiber profiles in transverse sections) and from the three-dimensional capillary-to-fiber ratios (3D CFR: capillary length per unit myofiber length). Increase in both suggests neoformation of additional capillary branches in parallel connection. Retrospective analysis of the quantitative data indicates that in hypertrophy induced by physical exercise or by chronic thyroxin application capillary neoformation in parallel connection counterbalances increase of oxygen diffusion distance due to myofiber enlargement. In renovascular hypertension, capillary neoformation in parallel connection does not occur. Studies on normal growth indicated both a slight decrease of LV of capillaries, as well as a continuous neoformation of additional capillary branches.
对心肌毛细血管的体视学研究表明，常用的毛细血管密度估算值（即单位横截面积内毛细血管轮廓的数量）低估了真正的毛细血管供应情况，因为毛细血管轴并非完全与肌纤维轴平行排列。最近，我们在已发表于其他地方的一些心脏肥大实验模型中研究了“真正的”毛细血管密度，即毛细血管的长度密度（LV = 每毛细血管体积的毛细血管长度）。结果显示，在肾血管性高血压中LV降低，但在体育锻炼和长期应用甲状腺素后LV保持不变。然而，肥大心脏中毛细血管的生长模式尚未得到分析。在本文中，我们证明了关于毛细血管网络的重要信息可以从二维毛细血管与纤维比率（2D CFR：横切面上每肌纤维轮廓的毛细血管轮廓）和三维毛细血管与纤维比率（3D CFR：每单位肌纤维长度的毛细血管长度）中得出。两者的增加表明有额外的平行连接的毛细血管分支形成。对定量数据的回顾性分析表明，在体育锻炼或长期应用甲状腺素诱导的肥大中，平行连接的毛细血管新生可抵消因肌纤维增大导致的氧扩散距离增加。在肾血管性高血压中，不存在平行连接的毛细血管新生。对正常生长的研究表明，毛细血管的LV略有下降，同时不断有额外的毛细血管分支形成。
