Chien G L, Anselone C G, Davis R F, Van Winkle D M
Department of Anesthesiology, Oregon Health Sciences University, Portland 97201, USA.
Cardiovasc Res. 1995 Sep;30(3):405-12.
This study compared simultaneous regional myocardial blood flow (RMBF) measurements using fluorescent microspheres (FM) and radiolabeled microspheres (RM). The utility of an internal standard during processing was also examined.
Paired FM and RM were injected into the left atrium of 9 anaesthetised rabbits. RMBF was altered by use of either regional ischaemia or (-)-N6-(2-phenylisopropyl)-adenosine. Radioactivity of blood reference and tissue samples was quantitated using standard methods. Samples were then digested with potassium hydroxide and microspheres recovered by vacuum filtration, with an additional label of FM as the internal standard. FM labels were extracted using Carbitol acetate and quantitated using fluorescence spectroscopy. Agreement between the fluorescent and radioactive methods was assessed using both orthogonal regression and difference-against-mean analyses.
Using recovery-uncorrected data, the slope of the orthogonal regression of RM and FM-determined RMBF was not statistically different from 1, but the intercept was statistically different from 0 [-0.03(0.01), P = 0.005] and the mean RMBF by each method differed from one another [1.24(0.08) vs. 1.17(0.08) ml.min-1.g-1, P = 0.0002]. The mean +/- 2 s.d. of the differences of RMBF (RM minus FM) was +0.07 +/- 0.30 ml.min-1.g-1. Although recovery of FM from tissue averaged 97.6(1.2)%, use of the internal standard to correct for losses substantially improved the agreement between RM and FM-determined RMBF: the orthogonal regression slope was not statistically different from 1, the intercept was not statistically different from 0, and the means of the flows were not different. The mean +/- 2 s.d. of the differences of RMBF was -0.01 +/- 0.22 ml.min-1.g-1. The internal standard also improved RMBF estimates from samples with simulated large spillage during processing.
Fluorescent microspheres are an equivalent alternative to radiolabeled microspheres for the estimation of RMBF. Although the overall recovery of microspheres using this technique was high, use of an internal standard is recommended for correction of random losses.
本研究比较了使用荧光微球（FM）和放射性标记微球（RM）同步测量局部心肌血流量（RMBF）的情况。还研究了处理过程中内标的效用。
将配对的FM和RM注入9只麻醉兔的左心房。通过局部缺血或（-）-N6-（2-苯异丙基）-腺苷改变RMBF。使用标准方法对血液参考样本和组织样本的放射性进行定量。然后用氢氧化钾消化样本，通过真空过滤回收微球，并额外标记FM作为内标。使用乙酸卡必醇提取FM标记，并使用荧光光谱法进行定量。使用正交回归和均值差异分析评估荧光法和放射性法之间的一致性。
使用未校正回收率的数据，RM和FM测定的RMBF的正交回归斜率与1无统计学差异，但截距与0有统计学差异[-0.03(0.01)，P = 0.005]，且每种方法的平均RMBF彼此不同[1.24(0.08)对1.17(0.
