Huxley V H, Williams D A
Department of Physiology, University of Missouri School of Medicine, Columbia 65212, USA.
Am J Physiol. 1996 Sep;271(3 Pt 2):H1099-108. doi: 10.1152/ajpheart.1996.271.3.H1099.
We have developed a new method to quantify solute flux per unit surface area and concentration gradient (JS/S delta C) from arterioles isolated from pig hearts. The apparent permeability (Ps) was assessed from measurements of JS/S delta C for two proteins, alpha-lactalbumin (alpha-lactalb) and porcine serum albumin (PSA), labeled with the fluorescent dye tetramethylrhodamine isothiocyanate at a mean hydrostatic pressure of 16 +/- 1 cmH2O. Ps for alpha-lactalb (Ps alpha-lactalb) was 16.5 +/- 4.6 x 10(-7) cm/s (mean +/- SE, N = 8 pigs), a value significantly higher than Ps for PSA (PsPSA) (7.1 +/- 1.4 x 10(-7) cm/s, N = 11 pigs, P < 0.05). Suffusion of the arterioles (44 +/- 10 microns diam; n = 48 arterioles) with 10(-5) M adenosine resulted in a 35% decrease in Ps alpha-lactalb and 29% decrease in PsPSA. Data from the present study are consistent with adenosine altering arteriole Js independently from its ability to change arteriolar caliber. One implication of these results is that changes in coronary exchange capacity reflect not only changes in flow through, but also solute permeation from, the microvasculature.
我们已经开发出一种新方法，用于量化从猪心脏分离出的小动脉单位表面积溶质通量和浓度梯度（JS/SδC）。在平均静水压力为16±1 cmH2O的条件下，通过测量用荧光染料异硫氰酸四甲基罗丹明标记的两种蛋白质α-乳白蛋白（α-lactalb）和猪血清白蛋白（PSA）的JS/SδC来评估表观渗透率（Ps）。α-乳白蛋白的Ps（Psα-lactalb）为16.5±4.6×10⁻⁷ cm/s（平均值±标准误，N = 8头猪），该值显著高于PSA的Ps（PsPSA）（7.1±1.4×10⁻⁷ cm/s，N = 11头猪，P < 0.05）。用10⁻⁵ M腺苷灌注小动脉（直径44±10微米；n = 48条小动脉）导致Psα-lactalb降低35%，PsPSA降低29%。本研究的数据与腺苷改变小动脉Js与其改变小动脉口径的能力无关相一致。这些结果的一个含义是，冠状动脉交换能力的变化不仅反映了通过微血管的血流量变化，还反映了溶质从微血管的渗透变化。
