Tanaka S, Matsuda Y, Shibamoto T, Wang H G
Department of Physiology, Shinshu University School of Medicine, Nagano, Japan.
J Auton Nerv Syst. 1996 Sep 12;60(3):121-8. doi: 10.1016/0165-1838(96)00041-0.
This experiment was designed to determine whether prolonged hemorrhagic hypotension in anesthetized monkeys produces differential control of tissue blood flow and sympathetic nerve activities to various organs (heart, kidney, liver, spleen, and hind-limb). We performed simultaneous multifiber recording of sympathetic nerve activity to the kidney (RNA), heart (CNA), spleen (SpNA), liver (HNA), and hind-limb (LNA) during sustained hemorrhagic hypotension at a mean blood pressure of 40 mmHg for 2 h. Immediately after bleeding, all of the sympathetic nerve activities increased significantly (Stage I) and then gradually decreased towards the prebleeding levels (Stage II). Thereafter, the secondary sympathetic excitation was observed (Stage III), followed by a gradual decrease in sympathetic activities below the prebleeding levels (Stage IV). The shed blood started to return to the animals at this final stage. Time course of changes in sympathetic nerve activities did not differ among organs innervated. However, tissue blood flow of the renal cortex, liver, skeletal muscle and spleen significantly decreased at Stage I and remained at low levels until the end of the experimental period. In contrast, blood flow of the renal medulla and heart was preserved until Stage III and Stage IV, respectively. These results indicate that although the sympathetic response to prolonged hemorrhagic hypotension of 40 mmHg did not differ among organs, changes in tissue blood flow were variable and blood flow to the heart and renal medulla was maintained at a steady level until a late stage of hemorrhage.
本实验旨在确定麻醉猴长时间出血性低血压是否会对不同器官（心脏、肾脏、肝脏、脾脏和后肢）的组织血流和交感神经活动产生不同的调控。我们在平均血压为40 mmHg的持续性出血性低血压状态下持续2小时，同时对支配肾脏（肾神经活动，RNA）、心脏（心脏神经活动，CNA）、脾脏（脾神经活动，SpNA）、肝脏（肝神经活动，HNA）和后肢（腰神经活动，LNA）的交感神经活动进行多纤维同步记录。出血后即刻，所有交感神经活动均显著增加（I期），随后逐渐降至出血前水平（II期）。此后，观察到继发性交感神经兴奋（III期），随后交感神经活动逐渐降至出血前水平以下（IV期）。在这最后阶段，开始将 shed blood 回输给动物。不同受支配器官的交感神经活动变化的时间进程并无差异。然而，肾皮质、肝脏、骨骼肌和脾脏的组织血流在I期显著减少，并在实验期结束前一直维持在低水平。相比之下，肾髓质和心脏的血流分别在III期和IV期之前得以保留。这些结果表明，尽管对40 mmHg长时间出血性低血压的交感神经反应在不同器官之间并无差异，但组织血流的变化是可变的，心脏和肾髓质的血流在出血后期之前一直维持在稳定水平。
