School of Energy and Power Engineering, Dalian University of Technology, Dalian, 116023, China.
Anhui Medical University, Hefei, China.
Med Biol Eng Comput. 2021 May;59(5):1151-1166. doi: 10.1007/s11517-021-02363-5. Epub 2021 Apr 29.
The aim of this study was to explore changes in the microvascular tone as measured by laser Doppler flowmetry (LDF) and the microcirculation structure of the dorsal skin of rats with type 2 diabetes mellitus. The diabetic rat model was induced by a diet of high-sugar and high-lipid fodder combined with the injection of streptozotocin into the abdominal cavity. Depending on the interval between the development of diabetes and the experiments, the diabetic rats were subdivided into three groups. The evaluation of microvascular tone was based on the amplitude responses of the LDF signal fluctuations in the appropriate frequency range in the dorsal skin of the rats during a thermal test (at 42 °C). The nitric oxide (NO) level in plasma was also used as a marker of endothelial dysfunction. Changes in the microcirculation structure in the diabetic rats were estimated by measuring the microvascular density in the choke vessels of the dorsal skin of the rats. The experimental results with respect to red blood cell (RBC)-related parameters showed decreased hematocrit and hemoglobin levels and increased standard deviation of the width of the RBC distribution in three diabetic rats. The increasing fluctuation amplitudes diminished in the endothelial frequency range in response to the thermal test and this was accompanied by abnormal NO levels in plasma of the diabetic groups as compared with healthy rats. A significant reduction in the microvascular density of the choke vessels of the dorsal skin was found only in the diabetic group at the most advanced stage of diabetes in this experiment. Thus, we suggest that endothelial dysfunction occurs in diabetic rats and changes in the microcirculation structure of the dorsal skin occur in a later stage of diabetes development. A. Photograph of measurement method by using a LDF probe and heating device in the dorsal skin of the rat. B. Dorsal skin LDF signals of a healthy rat during the thermal stimuli test. (a) Blood flow signal record for the test. Wavelet filtration of blood flow signal in (b) myogenic range, (c) neurogenic range, and (d) endothelial range.
本研究旨在探讨激光多普勒流量仪（LDF）测量的微血管张力变化和 2 型糖尿病大鼠背部皮肤微循环结构。糖尿病大鼠模型通过高糖高脂饲料喂养联合腹腔注射链脲佐菌素诱导。根据糖尿病发展与实验的时间间隔，将糖尿病大鼠分为三组。微血管张力评估基于大鼠背部皮肤在热刺激（42°C）下 LDF 信号波动的适当频率范围内的振幅响应。血浆中一氧化氮（NO）水平也可用作内皮功能障碍的标志物。通过测量大鼠背部皮肤梗塞血管的微血管密度来评估糖尿病大鼠的微循环结构变化。糖尿病大鼠红细胞（RBC）相关参数的实验结果显示，三组大鼠的红细胞压积和血红蛋白水平降低，RBC 分布宽度的标准差增加。对热刺激的反应中，内皮频率范围内的波动振幅增加，与健康大鼠相比，糖尿病组的血浆中 NO 水平异常。在本实验中，只有在糖尿病发展的最晚期阶段，才能发现大鼠背部皮肤梗塞血管的微血管密度显著降低。因此，我们认为内皮功能障碍发生在糖尿病大鼠中，而背部皮肤微循环结构的变化发生在糖尿病发展的后期阶段。A. 使用 LDF 探头和加热装置在大鼠背部皮肤测量方法的照片。B. 健康大鼠在热刺激测试期间的背部皮肤 LDF 信号。(a) 测试的血流信号记录。(b) 肌源性范围、(c) 神经源性范围和(d) 内皮源性范围的血流信号小波滤波。
