Sweeney T E, Sarelius I H
Department of Biophysics, University of Rochester, School of Medicine, New York 14642.
Circ Res. 1989 Jan;64(1):112-20. doi: 10.1161/01.res.64.1.112.
This study tests the hypothesis that capillary perfusion is controlled in groups rather than at the level of the individual capillary. We measured cell flux (using cells labeled with substituted tetramethyl rhodamine isothiocyanate, XRITC) and vessel diameter in adjoining arterioles of the terminal vasculature of hamster cremaster muscle (Nembutal, 70 mg/kg i.p.) during rest and hyperemia (10(-4) M adenosine). In terminal arterioles (TAs), 32 of 68 vessels showed cell flux increases from rest to hyperemia exceeding 25 times (i.e., 47% of TAs were relatively unperfused at rest). In vessels feeding TAs (TAFs), 33 of 95 (34%) were relatively unperfused at rest. Cell flux heterogeneity in TAFs decreased significantly by 27% from rest to hyperemia; the corresponding decrease (16%) in TAs was not significant. Thus, unperfused TAFs are present in a proportion which reflects capillary recruitment in hamster cremaster (Sarelius et al, Am J Physiol 1981;241:H317) while TAs are not, and TAFs independently modulate flow distribution distally while TAs do not. The data therefore support the conclusion that TAFs control cell flow in the distal microvasculature. Analysis of normalized ranked maximal diameters showed that TAFs unperfused at rest tend to be the smaller vessels at any tissue site.
本研究检验了这样一个假设，即毛细血管灌注是成组控制的，而非在单个毛细血管水平进行控制。我们在仓鼠提睾肌（腹腔注射70mg/kg戊巴比妥钠）终末血管系统相邻小动脉的静息期和充血期（10⁻⁴M腺苷）测量了细胞通量（使用异硫氰酸四甲基罗丹明替代物标记的细胞，XRITC）和血管直径。在终末小动脉（TA）中，68条血管中有32条从静息期到充血期细胞通量增加超过25倍（即47%的TA在静息期相对灌注不足）。在为TA供血的血管（TAF）中，95条中有33条（34%）在静息期相对灌注不足。从静息期到充血期，TAF中的细胞通量异质性显著降低了27%；TA中的相应降低（16%）不显著。因此，未灌注的TAF以一定比例存在，这反映了仓鼠提睾肌中的毛细血管募集情况（Sarelius等人，《美国生理学杂志》1981年；241:H317），而TA则不然，TAF独立调节远端的血流分布，而TA则不能。因此，数据支持TAF控制远端微血管中细胞流动的结论。对标准化排序的最大直径分析表明，静息期未灌注的TAF往往是任何组织部位中较小的血管。
