Development of microdialysis probe for the kidney and the heart

被称为微透析的“生物采样”技术最初是由Ungerstedt及其同事开发的。该方法的原理是从细胞外液（ECF）中提取代谢物，而不从组织中去除液体。基本装置是一个薄的（直径0.65毫米）双管探头。然而，对于在高血流速率下灌注的肾脏或心脏来说，这个尺寸相对较大。此外，由于这些器官的移动，探针的固定是困难的。此外，为了观察对各种刺激的快速反应，对探针的透析效率要求很高。因此，为了满足上述几点，我们尝试开发一种新的肾脏微透析探针。新探针的直径仅为0.2毫米，透析效率是商用探针的5-10倍。利用这种新研制的探针，我们进行了以下实验。1)肾内腺苷（Ado）代谢：多巴胺时的Ado浓度，更小的情况是在200 nM左右。缺血使脑损伤增加。大约3次。然而，用EHNA抑制ado脱氨酶后，ado脱氨酶恢复正常。缺血时增加50倍以上。另一方面，我想说的是。碘结核菌素抑制ado激酶后仅增加5倍。因此，肾缺血时细胞内产生的腺苷可能主要由ado脱氨酶代谢，ado的再磷酸化可能很小。2)氟烷（Hal）对肾脏一氧化氮（NO）代谢的影响：吸入Hal（2%）可降低血压和肾间质密度。吸入Hal后给予硝普苷（NP）使cGMP升高。这些发现表明，Hal抑制了肾脏一氧化氮-鸟苷酸环化酶信号通路，并且Hal对肾脏血流动力学的反应可能部分通过这种抑制而诱导。另外，可以推测Hal的作用位点可能在一氧化氮-鸟苷酸环化酶信号通路附近。因此，新开发的微透析探针是研究ECF中各种物质动力学的有用工具。少

The "bio-sampling" technique called microdialysis was originally developed by Ungerstedt and colleagues. The principle of this method is to extract metabolizes from the extracellular fluid (ECF) without removal of fluid from the tissue. The basic device is a thin (0.65 mm diameter) double lumen probe. However, this size is relatively large for the application to the kidney or heart which is perfused at high blood flow rate. Moreover, since these organs move, the fixation of probe is difficult. In addition, to observe the rapid responses to various stimuli high dialysis efficiency will be required for probe. Thus, in order to satisfy the above points, we have tried to develop a new microdialysis probe for the kidney. The diameter of the new probe is only 0.2 mm and the dialysis efficiency is 5-10 times greater than the commercial probe. Using this newly developed probe we have performed the following experiments. 1) Intrarenal adenosine (Ado) metabolism : Ado concentration (conc.) at ba … More sal condition was around 200 nM.Ischemia increased the ado conc.about 3 times. However, after the inhibition of ado deaminase with EHNA the ado conc. was increased more than 50 times during ischemia. On the other hand, ado conc.after the inhibition of ado kinase with iodotubercidine increased only 5 times. Thus, the adenosine produced in the cell during renal ischemia might be mainly metabolized by ado deaminase and the rephosphorylation of ado might be small. 2) Effects of halothane (Hal) on the metabolism of nitric oxide (NO) in the kidney : Inhalation of Hal (2%) decreased blood pressure and the renal interstitial conc.of cyclic GMP (cGMP) and NOx, Administration of nitroprusside (NP) under the inhalation of Hal increased cGMP.These findings suggested that Hal inhibited the nitric oxide-guanylate cyclase signaling pathway in the kidney, and the renal hemodynamic responses to Hal might be induced, in part, through this inhibition. In addition, it can be assumed that the action site of Hal might be proximal to the nitric oxide-guanylate cyclase signaling pathway. Thus, the newly developed microdialysis probe is a useful tool for studying the dynamics of various substances in ECF. Less