Lahlou Saad, Interaminense Leylliane Fátima Leal, Leal-Cardoso José Henrique, Duarte Gloria Pinto
Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife-PE, Brasil.
Fundam Clin Pharmacol. 2003 Jun;17(3):323-30. doi: 10.1046/j.1472-8206.2003.00150.x.
The present study investigated the hypotensive responses to intravenous (i.v.) treatment with the essential oil of Alpinia zerumbet (EOAZ) and its main constituent, terpinen-4-ol (Trp-4-ol), in the experimental model of deoxycorticosterone-acetate (DOCA)-salt hypertensive rat. In both DOCA-salt hypertensive and uninephrectomized, normotensive rats, i.v. bolus injections of EOAZ (1-20 mg/kg) or Trp-4-ol (1-10 mg/kg) decreased mean aortic pressure (MAP) in a dose-related manner. However, hypotensive responses to Trp-4-ol were significantly greater than those evoked by the same doses of EOAZ (1-10 mg/kg). Treatment with DOCA-salt significantly enhanced the maximal percentage decreases in MAP evoked by EOAZ or Trp-4-ol. Likewise, both maximal percentage and absolute decreases in MAP elicited by i.v. injection of the ganglion blocker, hexamethonium (30 mg/kg), were significantly greater in DOCA-salt hypertensive than in control rats. In DOCA-salt hypertensive rats, neither hexamethonium (30 mg/kg, i.v.) nor methylatropine (1 mg/kg, i.v.) pretreatment affected the enhancement of EOAZ-induced hypotension. These results show that i.v. treatment with either EOAZ or Trp-4-ol dose-dependently decreases blood pressure in conscious DOCA-salt hypertensive rats, and this action is enhanced when compared with uninephrectomized controls. This enhancement could be related mainly to an increase in EOAZ-induced vascular smooth muscle relaxation rather than to enhanced sympathetic nervous system activity in this hypertensive model. The data further support our previous hypothesis that hypotensive effects of EOAZ are partially attributed to the actions of Trp-4-ol.
本研究在醋酸脱氧皮质酮（DOCA）-盐高血压大鼠实验模型中，研究了山姜精油（EOAZ）及其主要成分萜品-4-醇（Trp-4-ol）静脉注射（i.v.）治疗的降压反应。在DOCA-盐高血压大鼠和单侧肾切除的正常血压大鼠中，静脉推注EOAZ（1-20mg/kg）或Trp-4-ol（1-10mg/kg）均以剂量相关的方式降低平均主动脉压（MAP）。然而，Trp-4-ol的降压反应明显大于相同剂量EOAZ（1-10mg/kg）所引起的反应。DOCA-盐处理显著增强了EOAZ或Trp-4-ol引起的MAP最大百分比下降。同样，静脉注射神经节阻滞剂六甲铵（30mg/kg）引起的MAP最大百分比和绝对下降在DOCA-盐高血压大鼠中均显著大于对照大鼠。在DOCA-盐高血压大鼠中，六甲铵（30mg/kg，静脉注射）或甲基阿托品（1mg/kg，静脉注射）预处理均不影响EOAZ诱导的低血压增强。这些结果表明，静脉注射EOAZ或Trp-4-ol均可使清醒的DOCA-盐高血压大鼠血压呈剂量依赖性下降，与单侧肾切除的对照相比，这种作用增强。这种增强可能主要与EOAZ诱导的血管平滑肌舒张增加有关，而不是与该高血压模型中交感神经系统活性增强有关。数据进一步支持了我们之前的假设，即EOAZ的降压作用部分归因于Trp-4-ol的作用。
