最后区注射腺苷对大鼠血压、心率和肾交感神经放电的影响(英文)

Effects of microinjection of adenosine into area postrema on heart rate, blood pressure and renal sympathetic nerve activity in rats

在 5 3只麻醉Sprague Dawley大鼠观察了最后区内微量注射腺苷 (1ng/ 6 0nl)对平均动脉压 (MAP)、心率(HR)和肾交感神经放电 (RSNA)的影响。实验结果如下 :(1)最后区内微量注射Ado后 ,MAP、HR和RSNA分别由13 76± 0 46kPa、35 6 2 8± 4 2 5bpm和 10 0± 0 %下降至 11 2 3± 0 49kPa (P <0 0 0 1)、336 91± 5 2 3bpm (P <0 0 1)和70 95± 5 19% (P <0 0 0 1) ;(2 )静脉注射非选择性腺苷受体拮抗剂 8 苯茶碱 (8 phenyltheophylline,15 0 μg/kg ,0 2ml)和选择性腺苷A1受体拮抗剂 (8 cyclopentyl 1,3 dipropylxanthine,5 0 0 μg /kg ,0 2ml)后 ,腺苷的上述抑制效应可被完全阻断 ;(3)静脉注射ATP敏感性钾通道阻断剂格列苯脲 (5mg/kg ,0 2ml)后 ,腺苷的上述效应也被消除。以上结果提示 ,最后区微量注射腺苷对血压、心率和肾交感神经放电有抑制作用 ,此作用与A1受体介导的ATP敏感性钾通道开放有关。

WT5”BZ] The effects of microinjection of adenosine (Ado) into area postrema (AP) on mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were examined in 53 anesthetized Sprague Dawley rats. The results obtained are as follows. (1) Following microinjection of Ado (1 ng/60 nl) into AP, MAP, HR and RSNA were decreased from 13 76±0 46 kPa, 356 28±4 25 bpm and 100±0% to 11 23±0 49 kPa ( P <0 001), 336 91±5 23 bpm ( P <0 01) and 70 95±5 19% ( P <0 001), respectively; (2) 8 phenyltheophylline (150 μg/kg, 0 2 ml,iv), a nonselective adenosine receptor antagonist, and 8 cyclopentyl 1,3 dipropylxanthine (500 μg/kg, 0 2 ml, iv), a selective A 1 adenosine receptor antagonist, blocked the inhibitory effect of Ado completely; and (3) glibenclamide (5 mg/kg, 0 2 ml, iv), a blocker of ATP sensitive potassium channel, also abolished the effect of Ado. The above results indicate that microinjection of Ado into AP induces inhibitory effects on MAP, HR and RSNA, which may be related to activation of ATP sensitive potassium channels mediated by A 1 receptors.