Skrha J, Stĕpán J
Third Department of Internal Medicine, Faculty of Medicine, Charles University, Prague, Czechoslovakia.
Acta Univ Carol Med Monogr. 1987;120:1-81.
Total amylase activity in serum and urine is formed by pancreatic (P) and salivary (S) isoenzymes. The evaluation of isoamylases provides better information on enzyme changes during the disease than total activities alone. The resolution of pancreatic from extrapancreatic origin of hyperamylasemia may be clinically important. The experience obtained from the analysis of isoamylases in more than 1500 patients with different clinical diagnoses we compare with a contemporary knowledge of disturbances in amylase activities. We developed a method separating quantitatively both isoamylases on the mini-columns of ion-exchanger which we used in routine clinical investigation. In the first section we selected the findings on physiology and biochemistry of isoamylases. We described for the first time a significant decrease of P-isoamylase activity in serum during the intravenous infusions of hypertonic glucose, amino acids and during acute hypercalcaemia. We suggested that hypertonic glucose, amino acids and calcium may regulate directly or indirectly the amylase flux from acinar cells in the pancreas across basolateral membrane into blood. This endocrine secretion of amylase may be important in different clinical conditions in which changes of neurohumoral and/or hormonal regulation are developed. The isoamylase activities in patients with different diagnosis are analyzed in the clinical section. The results may be correctly evaluated only in connection with the pathogenesis of isoamylase changes. Disorders of the organs producing amylase (i.e. pancreas or salivary glands) may induce changes of isoamylases depending on their functional status. A progressive loss of amylase producing cells may be accompanied by a decrease of enzyme activity in serum as was described in chronic pancreatitis with exocrine insufficiency. However, the amylase activity in serum is significantly influenced by clearance mechanisms, too. Disorders of the liver or kidneys are accompanied predominantly with hyperamylasemia caused by the disturbed clearance mechanisms. The amylase activity in serum is a consequence of the result between input and output of the enzyme within the blood stream. Some humoral and hormonal regulations are able to modulate both processes in vivo. We suppose that pathogenetic standpoint has the main role for correct interpretation of isoamylase activities. The pathogenesis of hyperamylasemia is therefore discussed in single chapters. In conclusion, the isoamylase activities in serum and urine are influenced beside genetic background by many factors in health and disease which may be respected during the evaluation of the results.
血清和尿液中的总淀粉酶活性由胰腺（P）和唾液（S）同工酶组成。与单独的总活性相比，同工淀粉酶的评估能提供有关疾病期间酶变化的更好信息。区分高淀粉酶血症的胰腺来源和胰腺外来源在临床上可能很重要。我们将对1500多名不同临床诊断患者的同工淀粉酶分析所获得的经验与当前关于淀粉酶活性紊乱的知识进行比较。我们开发了一种在离子交换剂微型柱上定量分离两种同工淀粉酶的方法，并将其用于常规临床研究。在第一部分，我们选取了关于同工淀粉酶生理生化的研究结果。我们首次描述了在静脉输注高渗葡萄糖、氨基酸以及急性高钙血症期间血清中P同工淀粉酶活性显著降低。我们认为高渗葡萄糖、氨基酸和钙可能直接或间接调节胰腺腺泡细胞中的淀粉酶通过基底外侧膜进入血液的通量。这种淀粉酶的内分泌分泌在神经体液和/或激素调节发生变化的不同临床情况下可能很重要。在临床部分分析了不同诊断患者的同工淀粉酶活性。只有结合同工淀粉酶变化的发病机制才能正确评估结果。产生淀粉酶的器官（即胰腺或唾液腺）的紊乱可能根据其功能状态诱导同工淀粉酶的变化。如在伴有外分泌功能不全的慢性胰腺炎中所描述的，产生淀粉酶的细胞逐渐丧失可能伴随着血清中酶活性的降低。然而，血清中的淀粉酶活性也受到清除机制的显著影响。肝脏或肾脏的紊乱主要伴随着清除机制紊乱导致的高淀粉酶血症。血清中的淀粉酶活性是酶在血流中输入和输出结果的体现。一些体液和激素调节能够在体内调节这两个过程。我们认为发病机制观点对于正确解释同工淀粉酶活性起着主要作用。因此，在单独的章节中讨论了高淀粉酶血症的发病机制。总之，血清和尿液中的同工淀粉酶活性除了受遗传背景影响外，在健康和疾病状态下还受到许多因素的影响，在评估结果时应予以考虑。
