Torry R J, Rongish B J, Tucker D C, Kostreva D R, Tomanek R J
Department of Anatomy, College of Medicine, University of Iowa, Iowa City 52242, USA.
Am J Physiol. 1996 Jan;270(1 Pt 2):H33-7. doi: 10.1152/ajpheart.1996.270.1.H33.
We have shown that sympathetic denervation increases subendocardial capillarity during left ventricular hypertrophy. To determine the direct effects of sympathetic innervation on development of the coronary microvasculature in the absence of hemodynamic load, we grafted avascular fetal rat atrial or ventricular tissue into the anterior eye chamber of host rats which had undergone unilateral superior cervical gangliectomies. Innervation to the contralateral eye chamber remained intact. The grafts were harvested 14 or 35 days later, and volume densities of blood vessels, myocytes, and extracellular matrix were determined using standard point-counting techniques on low-power electron micrographs. Graft perfusion and metabolism were assessed simultaneously with thallium-201 and 2-[14C]deoxy-D-glucose uptake, respectively. Innervation did not significantly alter the vascular volume densities or cellular composition of atrial or ventricular tissue compared with noninnervated tissue after either 14 or 35 days in oculo. Similarly, innervation did not significantly alter graft perfusion or metabolism. We conclude that sympathetic innervation does not directly influence the growth of the microvasculature or myocardial metabolism in hemodynamically unloaded, developing heart tissue.
我们已经表明，在左心室肥厚期间，交感神经去支配会增加心内膜下毛细血管密度。为了确定在没有血流动力学负荷的情况下交感神经支配对冠状动脉微血管发育的直接影响，我们将无血管的胎鼠心房或心室组织移植到单侧颈上神经节切除的宿主大鼠的前房。对侧眼房的神经支配保持完整。14或35天后收获移植物，使用标准点计数技术在低倍电子显微镜照片上测定血管、心肌细胞和细胞外基质的体积密度。分别用铊-201和2-[14C]脱氧-D-葡萄糖摄取同时评估移植物灌注和代谢。与眼内14天或35天后的无神经支配组织相比，神经支配并未显著改变心房或心室组织的血管体积密度或细胞组成。同样，神经支配也未显著改变移植物灌注或代谢。我们得出结论，在血流动力学无负荷的发育中的心脏组织中，交感神经支配不会直接影响微血管的生长或心肌代谢。
