Petty M, Reid J
Eur J Pharmacol. 1982 Aug 13;82(1-2):9-14. doi: 10.1016/0014-2999(82)90546-5.
The cardiovascular effects of Substance P (SP) administered into the cisterna magna (i.c.) of the pentobarbitone anaesthetised rabbit have been investigated. SP given i.c. in low doses (0.2-10 ng/kg) caused a dose related rise in blood pressure and bradycardia. Both responses were attenuated by pretreatment with intravenous (i.v.) pentolinium. SP given i.v. (1 ng/kg-1 microgram/kg) caused a dose related fall in pressure and tachycardia. The pressor response observed after i.c. administration was reduced by pretreatment with morphine and enhanced by naloxone. Bilateral sinoaortic denervation also enhanced the pressor effect of SP, but after deafferentation naloxone had no further effect. Pretreatment with clonidine abolished this rise in pressure. It is concluded that the central administration of SP has a direct pressor effect whereas the bradycardia appears to result from both direct and indirect effects, leading to a decrease in cardiac sympathetic activity. Both actions are mediated by the autonomic nervous system. SP may be involved in the central regulation of blood pressure and modulation of baroreceptor reflex activity.
已对将P物质（SP）注入戊巴比妥麻醉兔的脑池（颅内）后的心血管效应进行了研究。颅内给予低剂量（0.2 - 10 ng/kg）的SP会引起血压剂量相关的升高和心动过缓。两种反应均因静脉注射潘托铵预处理而减弱。静脉注射（1 ng/kg - 1 μg/kg）的SP会引起剂量相关的血压下降和心动过速。颅内给药后观察到的升压反应因吗啡预处理而降低，因纳洛酮而增强。双侧窦神经切断术也增强了SP的升压作用，但去传入神经后纳洛酮没有进一步作用。可乐定预处理消除了这种血压升高。结论是，中枢给予SP具有直接升压作用，而心动过缓似乎是由直接和间接作用共同导致的，从而导致心脏交感神经活动降低。两种作用均由自主神经系统介导。SP可能参与血压的中枢调节和压力感受器反射活动的调节。
