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

我们首先利用一种新型的视频系统研究了血管内压力与直径的关系。将它们放入装有Krebs-Henselit溶液的室中，该溶液的pH值保持在7.4以内，温度保持在37 ℃以内。用摄像机连续记录管腔内径和管壁厚度。在20- 30 mmHg的管腔内压力下，允许标本在60分钟内生理稳定。在10 ~ 180 mmHg的压力范围内，管腔内径和管壁厚度均发生变化，颅内主要动脉之一的大脑后动脉（PCA）在50 ~ 70 mmHg的压力范围内，管腔内径和管壁厚度均发生变化，超过此压力范围，PCA的管腔内径和管壁厚度均发生变化，而在50 ~ 70 mmHg的压力范围内，PCA的管腔内径和管壁厚度均发生变化。血压维持在恒定水平，然后下降，直到血压上升到90 - 100 mmHg。结果表明：50-70 mmHg的腔内压力足以使动脉产生主动性肌源性张力，当腔内压力增加到90-100 mmHg时，肌源性张力逐渐增强，当腔内压力超过140-150 mmHg时，肌源性张力出现滞后现象。结果表明，50 ~ 130 mmHg的压力是PCA的生理最适压力，并在此压力下考察了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经典类型的体外研究结果一致。因此，我们将集中在比较这些现象与那些从颅内动脉蛛网膜下腔出血。

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.