M受体机制在粉防己碱保护心脏缺血再灌注损伤作用中的影响

目的　探讨M受体对粉防己碱抗心脏缺血再灌注损伤作用的影响。方法　以离体豚鼠工作心脏缺血再灌注为心肌损伤模型 ,观察乙酰甲胆碱 (Mch ,0 1μmol·L-1) ,粉防己碱 (Tet,0 3μmol·L-1)的心肌保护作用。结果　对照组在缺血复灌后 2 0min ,主动脉压 (AP)、左室收缩压(LVSP)、左室压力上升最大速率 (+dp/dtmax) ,左室压力下降最大速率 (-dp/dtmax)仅分别恢复至缺血前的 6 5 6 %±3 6 9%、6 7 9%± 9 0 9%、5 8 8%± 7 6 4%、48 6 %±8 38%。Mch、Tet使AP恢复至缺血前的 80 7%±11 70 %、77 2 %± 6 96 % (P <0 0 1vscontrol) ,LVSP恢复至 97 9%± 6 32 %、93 9%± 10 1% (P <0 0 1vscon trol) ,+dp/dtmax 恢复至 91 2 %± 11 99%、80 0 3%±9 2 4% (P <0 0 1vscontrol) ,-dp/dtmax恢复至 92 13%±6 89%、79 43%± 8 83% (P <0 0 1) ;对照组复灌后心输出量 (CO)、冠脉流量 (CF)均降低 ,恢复率不足 5 0 % ;Mch、Tet能使CO、CF维持于缺血前水平的 90 %、80 %以上。给予阿托品 0 1μmol·L-1阻断心脏M受体可见Mch、Tet保护心功能的作用明显受到抑制 ,心功能各项指标恢复程度与对照组差异无显著性。结论　调节心脏M受体能影响Tet的心肌保护作用。

Beneficial effects of tetrandrine on functional recovery after ischemia and reperfusion in isolated-working hearts of guinea pigs: a mechanism involved in muscarinic stimulation

AIM To study the influence of muscarinic receptor antagonists on protective effects of tetrandrine against cardiac ischemia reperfusion injury METHOD The model of ischemia reperfusion (I R) injury in the isolated working heart of guniea pigs was used to investigate the protective effects of methacholine (Mch) and tetrandrine (Tet) on cardiac function RESULTS Mch, Tet enhanced the recovery of LVSP (97 9%±6 32%, 93 9%±10 1%, in Mch, Tet group respectively vs 67 9%±9 09% in I R group, P< 0 01), +d p /d t max (91 2%±11 99%, 80 03%±9 24% P< 0 01 vs control 58 8%±7 64%); -d p /d t max (92 13%±6 89%, 79 43%±8 83% P< 0 01 vs control 48 6%±8 38%) Mch and Tet also attenuated the decrease in CO, CF.Pretreatment with atropine (0 1 μmol·L -1 ) blocking cardiac M receptor almost eliminated the beneficial effects of Mch and Tet CONCLUSION Muscarinic receptor mechanisms contribute to myocardial protection and regulation of M receptor can modulate protective effects of Tet