Moldovan S, Livingston E, Zhang R S, Kleinman R, Guth P, Brunicardi F C
Department of Surgery, Veterans Affairs Medical Center-West Los Angeles, California, USA.
Am J Surg. 1996 Jan;171(1):16-20. doi: 10.1016/s0002-9610(99)80066-x.
To determine whether hyperglycemia affects pancreatic islet microcirculation in vivo and whether nitric oxide is a mediator.
Islet blood flow was measured before and after infusion of glucose during in vivo microscopy of mouse pancreatic islet. The pancreas of male BALB/c mice was exteriorized and viewed under the microscope utilizing monochromatic transmitted light. The carotid artery and tail vein were cannulated and systemic blood pressure was monitored continuously. Under fluorescent light, a 0.02 mL bolus of 2% fluorescein isothyocyanate (FITC-albumin) was injected intra-arterially and the first pulse of FITC-albumin through an islet capillary was videorecorded. Following equilibration, either glucose or normal saline 300 mg/g of body weight was given intravenously. Five minutes later, a second bolus was given and the second pulse was videorecorded. The study was repeated in the presence of N omega-nitro-L-arginine methyl ester (L-NAME). The FITC-albumin bolus mean transit time (TT) and observed cross time (OCT) through the islet were calculated using slow-motion video analysis of the recorded images.
Infusion of glucose resulted in a significant increase in islet blood flow with no change in systemic blood pressure: baseline TT was 20 +/- 1.3 pixel/0.03 sec and baseline OCT was 0.6 +/- 0.04 seconds; during hyperglycemia, TT was 16.1 +/- 1 pixel/0.03 sec, and OCT was 0.48 +/- 0.03 seconds (n = 11, P < 0.05 versus basal via paired t-test). Continuous infusion of L-NAME negated the effect of hyperglycemia on islet blood flow: baseline TT was 20 +/- 1.8 pixel/0.03 sec and OCT was and 0.6 +/- 0.05 seconds; during hyperglycemia, TT was 20 +/- 1.1 pixel/0.03 sec and OCT was 0.6 +/- 0.33 seconds (n = 10; P < 0.05 versus glucose via unpaired t-test).
确定高血糖是否会影响体内胰岛微循环，以及一氧化氮是否为介质。
在小鼠胰岛的体内显微镜检查过程中，于输注葡萄糖前后测量胰岛血流。将雄性BALB/c小鼠的胰腺暴露于体外，利用单色透射光在显微镜下观察。将颈动脉和尾静脉插管，并持续监测全身血压。在荧光灯下，经动脉注射0.02 mL 2%的异硫氰酸荧光素（FITC-白蛋白），并对通过胰岛毛细血管的FITC-白蛋白的第一个脉冲进行视频记录。平衡后，静脉注射300 mg/g体重的葡萄糖或生理盐水。五分钟后，给予第二次推注并记录第二个脉冲。在存在Nω-硝基-L-精氨酸甲酯（L-NAME）的情况下重复该研究。利用记录图像的慢动作视频分析计算FITC-白蛋白推注通过胰岛的平均通过时间（TT）和观察到的交叉时间（OCT）。
输注葡萄糖导致胰岛血流显著增加，而全身血压无变化：基线TT为20±1.3像素/0.03秒，基线OCT为0.6±0.04秒；在高血糖期间，TT为16.1±1像素/0.03秒，OCT为0.48±0.03秒（n = 11，配对t检验，与基础值相比P < 0.05）。持续输注L-NAME消除了高血糖对胰岛血流的影响：基线TT为20±1.8像素/0.03秒，OCT为0.6±0.05秒；在高血糖期间，TT为20±1.1像素/0.03秒，OCT为0.6±0.33秒（n = 10；未配对t检验，与葡萄糖组相比P < 0.05）。
