Lin M T, Yang J J
Department of Physiology, National Cheng Kung University Medical College, Tainan City, Taiwan, Republic of China.
Am J Physiol. 1994 Jun;266(6 Pt 2):H2489-96. doi: 10.1152/ajpheart.1994.266.6.H2489.
To test for the ability of the nigrostriatal dopamine (DA) system to influence cardiovascular function, experiments were carried out to assess the effects of electrical or chemical stimulation of the nigrostriatal DA system on arterial blood pressure, heart rate, and striatal DA release in anesthetized rats. Electrical stimulation of the substantia nigra pars compacta (SNC), in addition to enhancing the DA release in the corpus striatum (CS), elicited proportional hypertension and tachycardia. This could be mimicked by microinjection of two excitatory amino acids, kainic acid and glutamate, into the SNC area of rat brain. The SNC stimulation-induced hypertension, tachycardia, and increased striatal DA release were attenuated by prior destruction of the nigrostriatal DA system produced by intramedial forebrain bundle injection of 6-hydroxydopamine and by prior blockade of postsynaptic DA receptors produced by intra-CS injection of DA receptor antagonists, haloperidol or pimozide. The SNC stimulation-induced hypertension was attenuated by spinal transection, whereas the SNC stimulation-induced tachycardia was attenuated by bilateral vagotomy. The data suggest that stimulation of the nigrostriatal DA system produces both hypertension and tachycardia in rats.
为了测试黑质纹状体多巴胺（DA）系统影响心血管功能的能力，进行了实验以评估在麻醉大鼠中电刺激或化学刺激黑质纹状体DA系统对动脉血压、心率和纹状体DA释放的影响。除了增强纹状体（CS）中的DA释放外，电刺激黑质致密部（SNC）还会引起成比例的高血压和心动过速。这可以通过将两种兴奋性氨基酸，即红藻氨酸和谷氨酸微量注射到大鼠脑的SNC区域来模拟。通过内侧前脑束注射6-羟基多巴胺产生的黑质纹状体DA系统预先破坏，以及通过CS内注射DA受体拮抗剂氟哌啶醇或匹莫齐特产生的突触后DA受体预先阻断，均可减弱SNC刺激诱导的高血压、心动过速和纹状体DA释放增加。脊髓横断可减弱SNC刺激诱导的高血压，而双侧迷走神经切断术可减弱SNC刺激诱导的心动过速。数据表明，刺激黑质纹状体DA系统会在大鼠中产生高血压和心动过速。
