Höller M, Chalybäus C, Breuer H
Hoppe Seylers Z Physiol Chem. 1976 Sep;357(9):1215-21. doi: 10.1515/bchm2.1976.357.2.1215.
The isolated rat liver was perfused with a haemoglobin-free, albumin containing salt solution at 28 degrees and 37 degrees C, respectively, with [4-14C]oestrone as substrate. During perfusion, the functional state of the liver was checked by continuously measuring the oxygen pressure and hydrogen ion concentration in the perfusion medium, flow rate, oxygen tension at various areas of the liver surface, and oxygen consumption; in addition, the following biochemical parameters were determined: ATP, ADP, lactate and pyruvate in liver tissue, and lactate and pyruvate in the perfusion medium. After 30 min of perfusion, free steroids, steroid glucuronides, steroid sulphates and the remaining water-soluble metabolites, present in liver tissue, perfusion medium and bile, were separated from each other and characterised by thin-layer and paper chromatography. It was found that, during perfusion at 37 degrees C, less hydroxylated metabolites were formed than at 28 degrees C. In contrast, metabolites whose formation is not directly oxygen-dependent, such as glucuronides and sulphates, arose in higher amounts at 37 degrees C than at 28 degrees C. It may be concluded that the relative shortage of oxygen at 37 degrees C leads to a selective impairment of metabolic pathways requiring a sufficient supply of molecular oxygen. Since oxidative processes play an important role in the biogenesis and metabolism of steroid hormones, it is evident that results, obtained in perfusion experiments with haemoglobin-free media at 37 degrees C, must be treated with reserve.
分别在28℃和37℃下，用不含血红蛋白、含有白蛋白的盐溶液灌注分离出的大鼠肝脏，以[4-¹⁴C]雌酮作为底物。灌注过程中，通过连续测量灌注介质中的氧分压和氢离子浓度、流速、肝脏表面不同区域的氧张力以及氧消耗量来检查肝脏的功能状态；此外，还测定了以下生化参数：肝组织中的ATP、ADP、乳酸和丙酮酸，以及灌注介质中的乳酸和丙酮酸。灌注30分钟后，将肝组织、灌注介质和胆汁中存在的游离类固醇、类固醇葡萄糖醛酸苷、类固醇硫酸盐和其余水溶性代谢产物彼此分离，并通过薄层色谱法和纸色谱法进行鉴定。结果发现，在37℃灌注时形成的羟基化代谢产物比在28℃时少。相反，其形成不直接依赖氧气的代谢产物，如葡萄糖醛酸苷和硫酸盐，在37℃时的生成量比在28℃时更高。可以得出结论，37℃时相对缺氧会导致需要充足分子氧供应的代谢途径受到选择性损害。由于氧化过程在类固醇激素的生物合成和代谢中起重要作用，显然，在37℃下用不含血红蛋白的介质进行灌注实验所获得的结果必须谨慎对待。
