5-HT_(2A)RB对急性脑损伤致心肌损害及内源性去甲肾上腺素和5-羟色胺的影响

Effect of 5-HT_(2A)RB on the Myocardial Damage Caused by Acute Brain Injury and on Endogenous Norepinephrine and 5-hydroxytryptamine

目的通过了解5-羟色胺2A受体阻断剂(5-hydroxytryptamine2A receptor blocker,5-HT2ARB)对急性脑损伤致心肌损害的作用及内源性去甲肾上腺素(noradrenaline,NE)和5-羟色胺(5-hydroxytryptamine,5-HT)的影响,探讨NE、5-HT及其5-HT2AR在急性脑损伤致心肌损害中的作用。揭示急性脑损伤致心肌损害的本质并为临床防治工作提供实验依据。方法采用急性脑损伤动物模型,以心电图、心功能、肌酸激酶-MB同工酶(creatine kinase MB,CK-MB)含量、心肌HE染色及超微结构改变判断心肌损害程度。采用HPLC-ECD测定血浆及心肌组织NE和5-HT水平。采用RT-PCR和real-time RT-PCR方法测定5-HT2AR。将32只大鼠采用数字表法随机分为正常组、假手术组、急性脑损伤组和5-HT2AR阻断剂组,每组8只。急性脑损伤后24h观察大鼠各指标的变化。结果急性脑损伤致心肌损害表现为心电异常增多(P<0.05);心室收缩舒张功能降低,包括左心室内压上升和下降的最大变化率(±dp/dtmax)和左室发展压(left ventricular developed pressure,LVDP)显著下降(P<0.05),左室舒张末压(left ventricular diastolicend pressure,LVDEP)升高(P<0.05);CK-MB含量显著增加(P<0.05);HE染色和超微结构可见心肌灶状变性、坏死及出血等。血浆和心肌组织NE以及血浆5-HT水平显著升高(P<0.05)。应用5-HT2AR阻断剂后急性脑损伤所致心肌损害的指标明显改善,可降低心肌NE的含量(P<0.05)。结论急性脑损伤可导致心肌损害的发生,可能通过增加内源性5-HT而激活5-HT2AR引起心肌损害。5-HT2AR阻断剂可改善急性脑损伤致心肌损害的发生。

Objective To understand effects of norepinephrine(NE),5-hydroxytryptamine(5-HT) and 5-HT2AR on myocardial damage occurred after acute brain injury(MDABI) through studying role of 5-HT2ARB in the MDABI and its effect on endogenous NE and 5-HT and to provide further insights into the relationship between the brain and the heart,and the prevention and treatment of MDABI.Methods A rat model of acute brain injury(ABI) was established.ECG,cardiac function(CF),creatine kinase MB(CK-MB) in serum and morphologic cha...