Hafkenscheid J C, Hectors M P
Clin Chim Acta. 1977 Jul 1;78(1):23-7. doi: 10.1016/0009-8981(77)90334-5.
The influence of heparin on the estimation of aminotransferases was investigated in a reaction medium containing phosphate or Tris buffer. Heparin scarcely affects the ASAT determination, but the ALAT activity in plasma is about 70% of the activity in serum, when the enzyme determination is carried out in Tris buffer. There exists a lag phase due to which the decrease in absorbance with the incubation time is nonlinear. When the Tris buffer is omitted, the same lag phase is observed in the ALAT determination. This lag phase is not caused by the indicator enzyme LDH. Addition of phosphate to the incubation medium without any buffer abolishes this lag phase. The possibility exists that heparin influences the structure of the proteins present in plasma and that these proteins, in their turn, decrease the enzymatic activity of ALAT.
在含有磷酸盐或Tris缓冲液的反应介质中，研究了肝素对氨基转移酶测定的影响。肝素对天冬氨酸氨基转移酶（ASAT）的测定几乎没有影响，但当在Tris缓冲液中进行酶测定时，血浆中的丙氨酸氨基转移酶（ALAT）活性约为血清中活性的70%。存在一个延迟期，由于这个延迟期，吸光度随孵育时间的降低是非线性的。当省略Tris缓冲液时，在ALAT测定中观察到相同的延迟期。这个延迟期不是由指示酶乳酸脱氢酶（LDH）引起的。在没有任何缓冲液的孵育介质中添加磷酸盐可消除这个延迟期。有可能肝素影响血浆中存在的蛋白质的结构，而这些蛋白质反过来又降低了ALAT的酶活性。
