Effects of moxonidine injected into rostral ventrolateral medulla on blood pressure, heart rate, and renal sympathetic nerve activity in rats

摘要

AIM: To examine the effects of moxonidine (Mox) injected into the rostral ventrolateral medulla (RVLM) on blood pressure (BP), heart rate (HR), and the renal sympathetic nerve activity (RSNA) in anesthetized normotensive rats. METHODS: BP, HR, and RSNA were simultaneously recorded after 1 μL Mox 1, 10, and 100μmol·L~-1 was injected into RVLM. RESULTS: Mox 1, 10, and 100 μmol· L~-1 reduced BP from 13.9±1.0 kPa to 13.0±1.7 KPa (P<0.05), 13.8±1.8 kPa to 11.4±1.5 kPa (P<0.01), and 13.9±1.9 kPa to 9.4±1.7 kPa (P <0.01), respectively. Mox did not influence HR. RSNA varied with the doses: Mox 1 μmol·L~-1 increased RSNA by 50/100 (P<0.05), 10μmol·L~-1 insignificantly influenced RSNA (P>0.05), and 100 μmol·L~-1 reduced RSNA by 23/100 (P<0.05).