氯胺酮对脑缺血大鼠纹状体DA含量和Na~+,K~+-ATP酶活性的影响

目的研究脑缺血大鼠纹状体多巴胺含量和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的变化以及ＮＭＤＡ受体拮抗剂氯胺酮对这些变化的影响。方法采用大鼠４－Ｖ－Ｏ造成急性脑缺血模型，缺血１０ｍｉｎ后分别应用ＨＰＬＣ－ＥＣＤ和比色法测量纹状体ＤＡ含量以及Ｎａ＋，Ｋ＋－ＡＴＰ酶活性。结果脑缺血前１５ｍｉｎ腹腔注射氯胺酮（２５ｍｇｋｇ－１和５０ｍｇｋｇ－１）能明显拮抗脑缺血时ＤＡ含量和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低。结论氯胺酮可通过阻断ＮＭＤＡ受体，抑制纹状体ＤＡ释放和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低，对抗脑缺血损伤。

Effects of ketamine on the dopamine contents and the activity of ATPase in ischemic rat striatum

AIM To study the effect of ketamine (KT) on the dopamine (DA) contents and Na+,K+ ATPase activities in rats with transient cerebral ischemia. METHODS Animal model was prepeared by occlusion of four vessels (2 vertebral arteries and 2 common carotid arteries) (4 V O). The DA contents were assayed by high performance liquid chromatography (HPLC) coupled with electrochemical detection (ECD), and Na+,K+ ATPase activities were determined in rat striatum after 10 min of cerebral ischimia. RESULTS KT had cerebral protective effects so long as it was injected (25 mg·kg-1 and 50 mg·kg-1) intraperitoneally 15 min before ischemia began. KT obviously attenuated cerebral ischemia induced reduction of DA contents and Na+,K+ ATPase activities. CONCLUSIONS KT can block NMDA receptor mediated increase of DA release and antagonize the inhibition of Na+,K+ ATPase activities during cerebral ischemia, and this effects may be the important mechanisms by which ketamine protects cerebrum from ischemia induced neuronic damage.