心脏停跳复苏后全脑浅低温对脑组织前列环素和血栓素A_2含量的影响

Effects of the mild hypothermia of the whole brain of the amounts of 6-keto-PGF_(1a) and TXB_2 in brain tissues after canine cardiac arrest and resuscitation.

观察犬心脏停跳复跳后全脑浅低温（３４℃）对脑组织前列环素和血栓素 Ａ2 含量的影响。结 果表明，脑缺血再灌注后常规治疗４小时，６－ｋｅｔｏ－ＰＧＦ１ａ水平无明显变化，ＴＸＢ２含量明显上升（Ｐ＜ ０． ０１），ＴＸＢ２／６－ｋｔｅｏ－ＰＧＦ１ａ（Ｔ／Ｋ）比值明显升高（Ｐ＜０．０１）；浅低温治疗组与缺血再灌常规治疗组比较 ６－ｋｅｔｏ－ＰＧＦ１ａ水平仍无明显变化，而ＴＸＢ２含量下降（Ｐ＜０．０５），Ｔ／Ｋ比值降低（Ｐ＜０．０５）。提示全脑浅 低温能抑制脑缺血再灌后花生四烯酸环氧酶途径代谢，调整脑内前列环素与血栓素Ａ２的平衡，有利于 脑复苏。

To investigate the effects of mild hypothermia of whole brain (MHWB, 34℃) on the levels of prostacyclin and thromboxaneA2 in brain tissues after cardiac arrest and resuscitation,seventeen dogs were randomly divided into three groups:group A undergoing all procedures but cardiac arrest and treatment (n=5);group B given the routine cerebral resuscitation treatment (RCRT)after cardiac arrest lasting ten minutes and resuscitation (CAR) (n= 6);and group C receiving RCRT combined with MHWB after CAR (n=6), The samples of brain tissues were taken in group C following the MHWB duration of four hours,in group B immediately after the RCRT period of four hours and in group A after completing the required procedures,in which the contents of TXB2 and 6-keto-PGF1a were measured by radioimmunoassay. The results showed that as compared with those in group A, the 6-keto-PGF1a levels remained substantially unchanged in group B and C (P>0. 05 ), and the levels of TXB2 and TXB2/6-keto-PGF1a ratio increased significantly in group B (P<0. 01). but both maintained basically stable in group C (P>0. 05). In comparison with those in group B, the 6-keto-PGF1a level was kept essentially stable (P>0. 05 ), but the levels of TXB2 and TXB2/6-keto-PGF1a ratio decreased dramatically (P<0. 05). It is concluded that MHWB can depress the arachidonic acid metabolism through cyclooxygenase and keep a certain banlance between the activities of TXA2 and PGI2 during cerebral resuscitation.