失血性休克复苏大鼠心脏P-选择素表达与心脏功能的关系

目的 观察失血性休克复苏大鼠左心室功能与心肌组织中P-选择素表达的关系以及左旋精氨酸(L-Arg)对其影响,探讨失血性休克复苏大鼠心脏的损伤及保护机制.方法 健康SD大鼠30只,随机均分成正常对照组(NC组)、失血性休克复苏组(HS组)和左旋精氨酸治疗组(L-Arg组),通过生理记录仪观察左心功能的变化,采用酶联免疫吸附试验测定血清、心肌组织P-选择素含量,免疫组化方法检测心肌P-选择素蛋白表达.结果 休克大鼠复苏后3 h,HS组和L-Arg组血浆、心肌的P-选择素含量明显高于NC组;左心室内压最大变化速率、左心室内收缩压明显低于NC组,左心室舒张末期压明显高于NC组.但L-Arg组血浆、心肌组织中的P-选择素含量低于HS组,上述心功能指标的异常变化明显减轻.结论 大鼠失血性休克复苏后,P-选择素参与心脏损伤过程,L-Arg对P-选择素表达有抑制作用,对心脏功能具有保护作用.

Relationship between P-selectin and cardiac function in hemorrhagic shock resuscitation: experiment with rats

OBJECTIVE: To investigate the relationship between the left ventricular function and the expression of P-selectin in the serum and cardiac muscle in hemorrhagic shock resuscitation, and to evaluate the effects of L-arginine (L-Arg) against the harmful effect of P-selectin. METHODS: Thirty SD rats were randomly divided into 3 equal groups: hemorrhagic shock resuscitation (HS) group (undergoing bloodletting until the mean arterial pressure of 40 mm Hg and then re-infusion of the lost blood), L-Arg treatment group (undergoing bloodletting and then re-infusion with L-Arg simultaneously), and normal control (NC) group (undergoing infusion of normal saline). Cannulation was conducted via left carotid artery into the left ventricular to record left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), and left ventricular +/- dp/dtmax. Serum creatine kinase (CK) was detected by colorimetry. Three hours after the HS the rats were killed with samples of blood and apex of heart collected to detect the P-selectin expression by ELISA and immunohistochemistry. Microscopy was used to observe the expression of P-selectin in the vascular endothelial cells and cardiac muscle cells. RESULTS: The LVSP, maximal rate of LV pressure elevation (+ dp/dtmax), and maximal rate of LV pressure depression (- dp/dtmax) of the HS and L-Arg groups were all significantly lower than those of the NC group (all P < 0.01). The LVEDP of the HS and L-Arg groups were all higher than that of the NC group (both P < 0.01). Three hours after resuscitation, the CK levels of the HS and L-Arg groups were significantly higher than that of the NC group (both P < 0.01), and that of the L-Arg groups was significantly lower than that of the HS group (P < 0.05), the P-selectin levels of the serum and cardiac muscle cells of the HS and L-Arg groups were all significantly higher than those of the NC group (both P < 0.01), and those of the L-Arg group were significantly lower than those of the HS group (both P < 0.05). CONCLUSION: After hemorrhagic shock and resuscitation P-selectin may play an important role in cardiac injury, L-Arg can inhibit the expression of P-selectin, thus protecting the cardiac function against the harmful effect of P-selectin.