Urethane, but not pentobarbitone, attenuates presynaptic receptor function in rats: a contribution to the choice of anaesthetic
Urethane, but not pentobarbitone, attenuates presynaptic receptor function in rats: a contribution to the choice of anaesthetic
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DOI：
10.1111/j.1476-5381.2009.00315.x
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发表时间：
2009-08-01
影响因子：
7.3
通讯作者：
Schlicker, E.
中科院分区：
文献类型：
--
作者：
Kurz, C. M.;Baranowska, U.;Schlicker, E.
背景和目的：我们研究了大麻素CB 1和组胺H-3受体是否类似于α（2）-肾上腺素受体，因为它们的突触前介导的心血管效应在乌拉坦-比在戊巴比妥麻醉的pithedrats.Experimental方法：大麻素激动剂CP-55，940和H-3受体激动剂imetit对电诱导的心动过速和血管加压反应的影响，分别在乌拉坦或戊巴比妥麻醉的pithedrats中进行了比较。尿烷的三种受体的亲和力测定放射性配体结合研究在大鼠大脑皮层膜和其效力评估灌流小鼠组织预孵育H-3-noradrenaline.Key结果：神经源性心动过速反应的CP-55，940尿烷-比戊巴比妥麻醉脊髓大鼠显着抑制。伊美替可抑制戊巴比妥后的神经源性血管升压反应，但对乌拉坦无抑制作用。儿茶酚胺诱导的心动过速和血管加压反应没有不同的大鼠麻醉与任一化合物。氨基甲酸乙酯10毫米（血浆浓度达到麻醉下）没有影响结合CB 1或H-3受体和α（2）肾上腺素受体，也没有改变在三个受体激动剂对电诱发的H-3-去甲肾上腺素release.Conclusions和影响：氨基甲酸乙酯，但不是戊巴比妥，废除了H-3受体介导的血管反应在pithed大鼠和衰减CB 1受体介导的心脏反应比戊巴比妥多。CB 1、H-3和α（2）受体激动剂的较弱作用不能用乌拉坦在体外对三种受体的拮抗作用来解释。戊巴比妥，而不是氨基甲酸乙酯，是适合作为一种麻醉剂的研究抑制突触前受体功能的脊髓和麻醉大鼠。
Background and purpose:We examined whether cannabinoid CB1 and histamine H-3 receptors resemble alpha(2)-adrenoceptors in that their presynaptically mediated cardiovascular effects are less marked in urethane- than in pentobarbitone-anaesthetized pithed rats.Experimental approach:Effects of the cannabinoid agonist CP-55,940 and the H-3 receptor agonist imetit on electrically induced tachycardic and vasopressor responses, respectively, was compared in pithed rats anaesthetized with urethane or pentobarbitone. The affinity of urethane for the three receptors was measured by radioligand binding studies in rat brain cortex membranes and its potency assessed in superfused mouse tissues preincubated with H-3-noradrenaline.Key results:The neurogenic tachycardic response was less markedly inhibited by CP-55,940 in urethane- than in pentobarbitone-anaesthetized pithed rats. Imetit inhibited the neurogenic vasopressor response after pentobarbitone but not after urethane. The catecholamine-induced tachycardic and vasopressor response did not differ between rats anaesthetized with either compound. Urethane 10 mM (plasma concentration reached under anaesthesia) did not affect binding to CB1 or H-3 receptors and alpha(2) adrenoceptors, nor did it alter the inhibitory effect of agonists at the three receptors on electrically evoked H-3-noradrenaline release.Conclusions and implications:Urethane, but not pentobarbitone, abolished the H-3 receptor-mediated vascular response in pithed rats and attenuated the CB1 receptor-mediated cardiac response much more than pentobarbitone. The weaker effects of CB1, H-3 and alpha(2) receptor agonists cannot be explained by antagonism by urethane at the three receptors in vitro. Pentobarbitone, but not urethane, is suitable as an anaesthetic for investigations of inhibitory presynaptic receptor function in pithed and anaesthetized rats.