Kowallik P, Schulz R, Guth B D, Schade A, Paffhausen W, Gross R, Heusch G
Department of Pathophysiology, University of Essen Medical School, FRG.
Circulation. 1991 Mar;83(3):974-82. doi: 10.1161/01.cir.83.3.974.
The use of radioactive microspheres (RM) for the measurement of regional myocardial blood flow (RMBF) is limited and inaccessible to many investigators due to radiation safety concerns and radioactive waste disposal problems. Therefore, a new method for the measurement of RMBF using colored microspheres (CM) was developed.
Polystyrene spheres (diameter, 15 +/- 0.1 [SD] micron; density, 1.09 g/ml) were dyed with one of five colors. With the injection of CM into the left atrium or into a coronary perfusion line, RMBF and its distribution can be determined. CM are extracted from the myocardium and blood by digestion with potassium hydroxide and subsequent microfiltration. The dyes are then recovered from the CM within a defined volume of a solvent, and their concentrations are determined by spectrophotometry. The separation of composite absorbance spectra by spectrophotometry with the CM technique was as good as the separation of energy spectra by a gamma-counter using the RM technique. Leaching of dye from the CM was less than 0.1% during a 2-month period in vitro. Significant leaching of dye from the microspheres also did not occur during 8 hours in the blood and myocardium of four anesthetized dogs in vivo. For further validation of this method, pairs of CM and RM (15.5 +/- 0.1 [SD] microns) were simultaneously injected under five different RMBF conditions (range, 0-10 ml/[min.g]) into the left anterior descending coronary artery of four anesthetized pigs, with coronary inflow as a flow reference, or into the left atrium of four anesthetized dogs using aortic blood withdrawal as a reference. The relation between RMBF determined by CM and RM was CM = 0.01 + 1.00.RM (r = 0.98, n = 1,080 data points) in the pigs, and CM = -0.19 + 0.92.RM (r = 0.97, n = 1,813 data points) in the dogs.
Measurement of RMBF with CM yields values very similar to those of RM. Their use is less expensive and avoids all the disadvantages related to radioactivity, thus offering an alternative method for as many as five RMBF measurements in a single experiment.
由于辐射安全问题和放射性废物处理问题，放射性微球（RM）在测量局部心肌血流量（RMBF）方面的应用受到限制，许多研究人员无法使用。因此，开发了一种使用彩色微球（CM）测量RMBF的新方法。
将聚苯乙烯球（直径15±0.1[标准差]微米；密度1.09克/毫升）染成五种颜色之一。通过将CM注入左心房或冠状动脉灌注线，可以测定RMBF及其分布。通过用氢氧化钾消化并随后进行微滤从心肌和血液中提取CM。然后在限定体积的溶剂中从CM中回收染料，并通过分光光度法测定其浓度。使用CM技术通过分光光度法分离复合吸收光谱与使用RM技术通过γ计数器分离能谱一样好。在体外2个月期间，染料从CM中的浸出率小于0.1%。在四只麻醉犬的血液和心肌中，8小时内微球也未发生明显的染料浸出。为了进一步验证该方法，在五种不同的RMBF条件（范围为0-10毫升/[分钟·克]）下，将成对的CM和RM（15.5±0.1[标准差]微米）同时注入四只麻醉猪的左前降支冠状动脉，以冠状动脉流入作为流量参考，或注入四只麻醉犬的左心房，以主动脉抽血作为参考。在猪中，CM测定的RMBF与RM测定的RMBF之间的关系为CM = 0.01 + 1.00.RM（r = 0.98，n = 1080个数据点），在犬中为CM = -0.19 + 0.92.RM（r = 0.97，n = 1813个数据点）。
用CM测量RMBF得到的值与RM非常相似。其使用成本较低，避免了与放射性相关的所有缺点，从而为单次实验中的多达五次RMBF测量提供了一种替代方法。
