Kim S, Dorscher-Kim J, Liu M T, Trowbridge H O
Department of Endodontics, School of Dental and Oral Surgery, Columbia University, New York, NY 10032.
Arch Oral Biol. 1988;33(5):305-9. doi: 10.1016/0003-9969(88)90062-3.
A dose of the vasoactive substance P (SP), affecting local circulation only (0.0001-0.001 micrograms/kg body weight) when given by a close injection into the maxillary artery, caused a biphasic flow response in pulpal blood flow (PBF), as measured by a radioisotope-labelled 15 micron microsphere injection technique. Immediately after the SP injection, PBF increased some 66 per cent (p less than 0.02) and vascular hindrance (Z) decreased to 40 per cent against control values (p less than 0.02), indicating vasodilation. Thirty seconds after the SP injection, PBF decreased by 53 per cent (p less than 0.05), and pulpal Z increased 139 per cent against control values (p less than 0.02), indicating decreased blood flow. This biphasic flow response may be due to the active vasodilation of arterioles by SP, which causes a compression of venules and hence a reduction of PBF in what is a low-compliance system.
当通过上颌动脉近距离注射给予仅影响局部循环的血管活性物质P（SP）（0.0001 - 0.001微克/千克体重）时，采用放射性同位素标记的15微米微球注射技术测量，牙髓血流（PBF）出现双相血流反应。SP注射后立即，PBF增加约66%（p < 0.02），血管阻力（Z）降至对照值的40%（p < 0.02），表明血管舒张。SP注射后30秒，PBF下降53%（p < 0.05），牙髓Z相对于对照值增加139%（p < 0.02），表明血流减少。这种双相血流反应可能是由于SP使小动脉主动舒张，导致小静脉受压，从而在低顺应性系统中使PBF降低。
