Effects of dexmedetomidine on cardiorespiratory regulation in spontaneously breathing newborn rats.
Effects of dexmedetomidine on cardiorespiratory regulation in spontaneously breathing newborn rats.
复制标题
右美托咪定对自主呼吸新生大鼠心肺调节的影响。
DOI：
10.1111/pan.12530
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Saiki C.
中科院分区：
文献类型：
--
作者：
Tamiya J;Ide R;Takahashi M;Saiki C.
研究背景右美托咪定（Dexmedetomidine）是一种选择性α2肾上腺素受体激动剂，是一种新型的镇静剂。麻醉恢复后，大鼠接受生理盐水（NS，溶剂）、右美托咪定（50 μg·kg−1）或右美托咪定（50 μ g·kg − 1）的腹膜内给药，5 min后给予NS或选择性α2肾上腺素受体拮抗剂阿替美唑（1 mg·kg−1）（每组n= 10）。结果与对照组相比，右美托咪定组心率（HR）和每分钟通气量（V′E）显著降低（P<0. 0 5），而生理盐水组无此作用。阿替美唑组大鼠右美托咪定给药后HR和V ′ E的下降幅度明显小于NS组（P<0.0 5）。右美托咪定相关V ′ E抑制归因于呼吸频率（fR）显著降低，而不是潮气量（VT）。结论右美托咪定可明显降低自主呼吸幼鼠的HR和V ′E。由于阿替美唑完全逆转了R内的降低，因此V 'E，右美托咪定相关的呼吸抑制主要通过α2肾上腺素受体相关的R抑制发生。
BackgroundDexmedetomidine, a selectiveα2‐adrenoceptor agonist, is a new sedative agent.ObjectiveTo examine the dexmedetomidine‐associated changes in cardiorespiratory indices in spontaneously breathing newborn rats.MethodsAn abdominal catheter to administer drugs and subcutaneous electrodes to record electrocardiographic data were inserted into 2‐ to 4‐day‐old rats under isoflurane anesthesia; the rats were then placed in individual chambers. After recovery from the anesthesia, the rats received intraperi‐toneal administrations of normal saline (NS, vehicle), dexmedetomidine (50 μg·kg−1), or dexmedetomidine (50 μg·kg−1) followed 5 min later with NS or the selectiveα2‐adrenoceptor antagonist atipamezole (1 mg·kg−1) (n= 10 in each group). Cardiorespiratory indices were recorded for each animal throughout the experiment.ResultsDexmedetomidine administration significantly decreased heart rate (HR) and minute ventilation (V′E) (P<0.05) compared with control, whereas NS administration did not. The decrease in HR andV′Eafter dexmedetomidine administration was significantly less in rats that received atipamezole (P<0.05) than in those that received NS after dexmedetomidine administration. The dexmedetomidine‐associatedV′Edepression was attributed to a significant decrease in respiratory frequency (fR) but not tidal volume (VT). The change infRwas reversed by atipamezole administration, which itself induced no significant changes in HR andfR.ConclusionIn spontaneously breathing immature rats, dexmedetomidine administration significantly reduced HR andV′E. Because atipamezole fully reversed decreases infRand thereforeV′E, dexmedetomidine‐related respiratory suppression occurs predominantly throughα2‐adrenoceptor‐related suppression offR.