Kim B K, Baldini M G
Division of Hematologic Research, The Memorial Hospital, Pawtucket, Rhode Island, USA.
Transfusion. 1974 Mar-Apr;14(2):130-8. doi: 10.1111/j.1537-2995.1974.tb04504.x.
The nature of the platelet response to osmotic shock and its relationship to platelet viability were studied. Light absorbancy changes of human platelet concentrates exposed to hypotonic shock were measured in a spectrophotometer: a sudden drop of light absorbancy was followed by a reversal of light absorbancy towards normal (reversal reaction). It was confirmed that the reversal reaction is a complex phenomenon dependent on the integrity of biochemical and enzymatic functions of the platelets. It was suppressed by glycolytic inhibitors and by SH-blocking agents. Ouabain had no immediate effect, but with prolonged incubation it depressed the reaction. Suspension of the platelets in a protein-free medium caused a rapid loss of the reversal reaction. Disappearance of the marginal bundle of microtubules by exposure to colchicine did not change the reaction leading to the hypothesis that microfibrils rather than the microtubules may have been responsible for the reversal reaction. The conclusion was derived that the reversal reaction is due to cell volume contraction for which integrity of the platelet contractile protein and energy availability are essential. Platelet storage at 4 degrees C or at 22 degrees C caused a progressive depression of the reversal reaction which was more severe in platelets preserved at 4 C than in those preserved at 22 degrees C, and paralleled the loss of the platelet capacity to survive in vivo. Cryoprotective agents (DMSO, DMAC and glycerol) partially inhibited the reversal reaction. Freezing with these agents caused a more severe depression of the reaction. The least depression was observed with 5 per cent DMSO. The results demonstrated that the reversal reaction is a valid and accurate in vitro indicator of in vivo platelet viability when the results to be compared are limited to a single method of storage. Usefulness of the reversal reaction is reduced when results obtained with different methods of storage are compared.
研究了血小板对渗透压休克的反应性质及其与血小板活力的关系。在分光光度计中测量了暴露于低渗休克的人血小板浓缩物的光吸收变化：光吸收突然下降后，光吸收又恢复到正常水平（逆转反应）。证实逆转反应是一种复杂的现象，取决于血小板生化和酶功能的完整性。它被糖酵解抑制剂和SH阻断剂所抑制。哇巴因没有立即产生影响，但长时间孵育会抑制该反应。将血小板悬浮在无蛋白培养基中会导致逆转反应迅速丧失。用秋水仙碱处理使微管边缘束消失，并未改变该反应，从而得出这样的假设，即微原纤维而非微管可能是逆转反应的原因。得出的结论是，逆转反应是由于细胞体积收缩所致，而血小板收缩蛋白的完整性和能量供应对此至关重要。血小板在4℃或22℃保存会导致逆转反应逐渐受到抑制，在4℃保存的血小板中比在22℃保存的血小板中更严重，并且与血小板在体内存活能力的丧失平行。冷冻保护剂（二甲基亚砜、二甲基乙酰胺和甘油）部分抑制了逆转反应。用这些试剂冷冻会使反应受到更严重的抑制。5%的二甲基亚砜造成的抑制作用最小。结果表明，当要比较的结果仅限于单一储存方法时，逆转反应是体内血小板活力的有效且准确的体外指标。当比较用不同储存方法获得的结果时，逆转反应的实用性会降低。
