[A Review] The biorhythms of every species are precisely regulated to adapt the environmental changes. The function of biorhythms is controlled by the clock genes in either a single cell or the whole body. The function of clock genes depends on the feedback circles that are composed by the interactions among the clock components. Many studies indicate that circadian clock is closely related to diseases. Several cardiovascular diseases such as myocardial ischemia and myocardial infarction show overt circadian rhythms, indicating that clock genes may play an important role in such kinds of diseases.
目的研究2型糖尿病大鼠肠系膜微血管和微血流的变化。方法Otsuka-long-evans-tokushi ma fatty(OLETF)2型糖尿病大鼠33只,对照组long-evans tokushi ma otsuka(LETO)非糖尿病大鼠7只,全麻状态下,使用带电脑图像处理装置的微循环活体观察电视显微镜对糖尿病和非糖尿病对照组大鼠作活体肠系膜微循环观察。检测微血管分支数目、微动脉及微静脉口径、微静脉中沿壁滚动与贴壁黏附的白细胞数、微动脉边流和轴流的宽度、内皮细胞厚度等。实验结果经电视录像记录后用图像处理系统定量测定。结果糖尿病大鼠肠系膜微血管分支数与对照组大鼠比较减少24.5%(P<0.01),微血管分支数与血糖水平呈负相关(r=-0.44,P<0.05);糖尿病大鼠微动脉边流宽度小于对照组,边流与管径的比值显著减少(P<0.01),沿壁滚动与贴壁黏附白细胞明显增加(P<0.01),免疫细胞化学结果显示糖尿病大鼠肠系膜微血管内皮细胞表面血管细胞黏附分子1(Vascular cell adhesion molecule-1,VCAM-1)表达明显增强。结论糖尿病大鼠肠系膜微循环出现明显的微血管与微血流形态、结构和功能障碍,这些变化是糖尿病微血管病和各种并发征发生的基础。
