Developement of side-on typed needle-probe for CCD microscope

为了评价心脏收缩对心肌内微血管的影响，我们使用带CCD摄像机的针探头视频显微镜测量了跳动的狗心脏的壁内小动脉和小静脉直径的相位变化。并与心外膜微血管和心内膜微血管的结果进行了比较。在12只麻醉开胸犬上，将针形探头插入离心肌表面3-6 mm处。在获得壁内血管的清晰图像后，将探针尖端拉离微血管数十微米，以避免直接压迫血管。微血管的观察进行了很短的时间，并立即停止时，微血管有出血。测量血管段的直径，显示相对均匀的直径变化。壁内小动脉的相位性直径变化为：从<plus-minus>舒张末期的130 79 μ m到收缩末期的118 <plus-minus>72 μ m（平均<plus-minus>SD）（p&lt;0.001，n=21，变化10.6%<plus-minus>），而小静脉的相位性直径变化为8544 μ m到8642 μ m（无显著性，n=15，<plus-minus>2.6%）。与此相反，心内膜微动脉和微静脉的直径从舒张末期到收缩末期分别减小了<plus-minus>10.8%（P&lt;0.001）和<plus-minus>12.10%（P&lt;0.001）。心外膜小动脉内径在心动周期内无明显变化，小静脉内径<plus-minus>从心动末期到收缩末期增加9.8%（P&lt;0.01）。结果表明，心肌壁内小动脉从收缩末期到收缩末期直径减小的规律与心肌内膜下小动脉相似，而心外膜下小动脉的直径变化不大。而壁内微静脉的内径从舒张末期到收缩末期几乎不变，内膜下微静脉的内径减小，心外膜下微静脉的内径减小，

To evaluate the effect of cardiac contraction on intramyocardial microvessels, we measured the phasic change in the diameter of the intramural arterioles and venules of beating dog hearts using a needle-probe video-microscope with a CCD camera. We also compared the result with that of the epicardial microvessels and the endocardial microvessels. In 12 open-chest anesthetized dogs, the needle-probe was inserted 3-6 mm into the myocardium from myocardial surface. The probe tip was pulled several tens micrometers away from the microvessels to avoid direct compression of the vessels after obtaining clear image of the intramural vessels. The observation of microvessels was performed for a short time and was discontinued immediately when the microvessels had a hemorrhage. The diameter was measured for the vascular segment showing a relative uniform diameter change. the phasic diameter change in the intramural arterioles was from 130<plus-minus>79mum in end-diastole to 118<plus-minus>72mum (mean<plus-minus>SD) in end-systole (p<0.001, n=21, 10<plus-minus>6% change) and that in venules from 8544mum to 8642mum (not significant, n=15, 2<plus-minus>6%). In contrast, the diameter of the endocardial arterioles and venules decreased by 10<plus-minus>8% (p<0.001) and 12<plus-minus>10% (p<0.001) from end-diastole to end-systole, respectively. The diameter of the epicardial arterioles was almost unchanged during cardiac cycle and venular diameter increased by 9<plus-minus>8% (P<0.01) from end-diastole to end-systole. We conclusion, the diameter of the intramural arterioles decreased from end-diastole to end-systole in a similar way to subendocardial arterioles, but that of subepicardial arterioles changed very little. On the other hand, the diameter of the intramural venules was almost unchanged from end-diastole to end-systole, while the diameter of subendocardial venules decreased and that of subepicardial ve