Sutoo D, Akiyama K
Institute of Medical Science, University of Tsukuba, Japan.
Neurosci Lett. 1999 Jul 16;269(3):133-6. doi: 10.1016/s0304-3940(99)00427-9.
The effects of intracerebroventricular (i.c.v.) administration of dopamine receptor antagonists on the calcium-dependent brain function that reduces blood pressure were investigated. The systolic blood pressure of spontaneously hypertensive rats (SHR; male, 13 weeks of age) was reduced following i.c.v. administration of calcium chloride (100 microg/rat), and this effect of calcium chloride was attenuated by i.c.v. injection of eticlopride (dopamine D2 receptor antagonist, 100 microg/rat), but not by i.c.v. injection of SCH 23390 (dopamine D1 receptor antagonist, 30 microg/rat). Taking into consideration these results with our previous reports, it is suggested that calcium enhances dopamine synthesis in the brain through a calmodulin-dependent system, and that the resultant increase in dopamine levels inhibits sympathetic activity via the dopamine D2 receptor in the brain and reduces the blood pressure in SHR.
研究了脑室内（i.c.v.）注射多巴胺受体拮抗剂对降低血压的钙依赖性脑功能的影响。给自发性高血压大鼠（SHR；雄性，13周龄）脑室内注射氯化钙（100微克/只大鼠）后，其收缩压降低，而脑室内注射依替必利（多巴胺D2受体拮抗剂，100微克/只大鼠）可减弱氯化钙的这种作用，但脑室内注射SCH 23390（多巴胺D1受体拮抗剂，30微克/只大鼠）则无此作用。结合这些结果和我们之前的报告，提示钙通过钙调蛋白依赖性系统增强脑内多巴胺合成，由此导致的多巴胺水平升高通过脑内多巴胺D2受体抑制交感神经活动，从而降低SHR的血压。
