Research on differences in mechanical property between normal and spastic arterial wall.

我们首先检查血管内压力和直径之间的关系，使用一种新型的视频系统。在手术显微镜下，切除SD大鼠颅内大动脉（长度=2mm）。它们被放入充满krebs-Henselit溶液的室中，保持pH值在7.4，温度在37℃。用摄像机监测腔内直径和壁厚，并连续记录。在20-30mmHg的腔内压力下，让标本在60分钟内生理稳定。增加10 mmHg至180mmHg至180mmHg时，观察到腔内直径和壁厚的变化。当腔内压力高达50 ~ 70 mmHg时，以脑后动脉（PCA）为代表的颅内大动脉之一，内径增大。然而，超过这个水平，它保持在恒定的水平，然后下降，直到压力上升到90至100毫米汞柱。超过这个压力水平，直径就被迫不断地增大。这些结果表明，50-70 mmHg的腔内压力足以产生活跃的动脉肌张力，当压力增加到90-100 mg时，张力发展。当血压超过140 ~ 150 mmHg时，出现迟滞。综上所述，50 ~ 130 mmHg是PCA的最佳生理压力。在这个压力水平下检查PCA的药理学特性。在正常PCA中，钙拮抗剂、PKC抑制剂和经典激动剂的作用与体外经典型研究结果一致。因此，我们将把这些现象与蛛网膜下腔出血的颅内动脉的现象进行比较。

We examined first the relationship between intravascular pressure and diameter, using a novel type of videosystem.Under an operating microscope, intracranial major arteries of SD rat were excised (length=2mm). They were ste to the chamber filled with krebs-Henselit solution, which was kept within 7.4 in pH and 37C in temperature. The intraluminal diameter and wall thickmess was monitored by a videocamera and continuously recorded. The specimen was allowed to be physiologically stabilized within 60 minites under 20-30mmHg of intraluminal pressure. At an increment of 10 mmHg up to 180mmHg up to 180mmHg, change in the intraluminal diameter and wall thickmess was observed.Up to 50 to 70 mmHg of the intraluminal pressure the poesterior cerebral artery (PCA) as a representative one of the intracranial major arteries, the diameter increased.However, beyond this level, it stayd at the constant level and then decreased until the pressure went up to 90 to 100 mmHg. More than this level of pressure, the diameter was forced to increase in invariably.These results suggested that 50-70 mmHg of the intraluminal pressure was enough to yield active myogenic tonus of the artery and the tonus developed as the pressure increased up to 90-100 mg.The pressure beyhond 140-150 mmHg led to the hysteresis. It is surmized that the pressure ranging 50 to 130 mmHg was physiologically optimal to PCA.The pharmacological character of PCA was examine at this level of pressure. In the normal PCA,the effects of calcium antagonist, PKC inhibitors and classic agonists were in accordance with the results obtained from the classic type of in vitro study. Thus, we will focuse on the comparison of these phenomena with those obtained from intracranial arteries subjected to subarachnoid hemorrhage.