Coleman M D, Simpson J, Jacobus D P
Department of Pharmaceutical Sciences, Aston University, Birmingham, U.K.
Biochem Pharmacol. 1994 Oct 7;48(7):1349-54. doi: 10.1016/0006-2952(94)90556-8.
We have studied the efflux of dapsone hydroxylamine from normal and diabetic erythrocytes by the use of a two-compartment (1 and 2) in vitro dialysis system, in order to model the in vivo blood supply to the bone marrow. When both types of erythrocytes were dialysed against mononuclear leucocytes, the hydroxylamine crossed the membrane and caused significantly greater white cell death compared with dialysis of leucocytes against untreated erythrocytes. However, in the case of both normal and diabetic cells, the presence of the glutathione depletor diethyl maleate (DEM) caused a marked reduction in movement of hydroxylamine from compartment 1 to 2. Diethyl dithiocarbamate (DDC), a methaemoglobin accelerant, caused a marked reduction in movement of hydroxylamine from erythrocytes (diabetic and normal) in compartment 1 to 2 which led to a significant reduction in white cell death compared with the absence of DDC (18.3 +/- 5.5 vs 34.8 +/- 8.1%, P < 0.05). Dapsone recovery from compartment 1 rose significantly in the presence of DDC compared with control in both erythrocyte types. In contrast, recovery of dapsone from normal erythrocytes incubated in compartment 1 was significantly reduced by the presence of DEM compared with control, although there was no difference between control and DEM-treated diabetic cells. Dapsone analysis in compartment 2 revealed a significant increase in dapsone recovery in both diabetic (11.3 +/- 1.1%) and normal (11.9 +/- 1.1%) erythrocytes in the presence of DDC compared with diabetic (3.3 +/- 0.4%) and normal control (4.8 +/- 2.0%, P < 0.001). The presence of DEM in compartment 1 caused a significant fall in dapsone recovery in compartment 2 (3.7 +/- 0.26) compared with control (4.7 +/- 0.36%, P < 0.05). Hence, dapsone hydroxylamine is capable of leeching out of normal and diabetic erythrocytes, traversing a semipermeable membrane and causing toxicity to human mononucleocyte cells in vitro. This process may be one of the first stages in immune-mediated agranulocytosis.
为了模拟体内骨髓的血液供应情况，我们使用两室（1和2）体外透析系统研究了氨苯砜羟胺从正常和糖尿病红细胞中的流出情况。当两种类型的红细胞与单核白细胞进行透析时，与白细胞与未处理的红细胞透析相比，羟胺穿过膜并导致白细胞死亡显著增加。然而，对于正常和糖尿病细胞而言，谷胱甘肽消耗剂马来酸二乙酯（DEM）的存在导致羟胺从1室向2室的移动显著减少。甲硫血红蛋白促进剂二乙基二硫代氨基甲酸盐（DDC）导致羟胺从1室中的红细胞（糖尿病和正常）向2室的移动显著减少，与不存在DDC相比，这导致白细胞死亡显著减少（18.3±5.5%对34.8±8.1%，P<0.05）。与对照相比，在两种红细胞类型中，DDC存在时1室中氨苯砜的回收率显著提高。相比之下，与对照相比，DEM的存在使1室中孵育的正常红细胞中氨苯砜的回收率显著降低，尽管对照和经DEM处理的糖尿病细胞之间没有差异。2室中的氨苯砜分析显示，与糖尿病（3.3±0.4%）和正常对照（4.8±2.0%，P<0.001）相比，DDC存在时糖尿病（11.3±1.1%）和正常（11.9±1.1%）红细胞中氨苯砜的回收率显著增加。1室中DEM的存在导致2室中氨苯砜的回收率与对照相比显著下降（3.7±0.26）（4.7±0.36%，P<0.05）。因此，氨苯砜羟胺能够从正常和糖尿病红细胞中渗出，穿过半透膜并在体外对人单核细胞产生毒性。这个过程可能是免疫介导的粒细胞缺乏症的最初阶段之一。
