Laboratório de Enzimologia e Controle do Metabolismo (LabECoM), Departamento de Fármacos, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
FEBS Lett. 2011 Jan 3;585(1):92-8. doi: 10.1016/j.febslet.2010.11.009. Epub 2010 Nov 11.
We examined the effects of lactate on the enzymatic activity of hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK) in various mouse tissues. Our results showed that lactate inhibited PFK activity in all the analyzed tissues. This inhibitory effect was observed in skeletal muscle even in the presence of insulin. Lactate directly inhibited the phosphorylation of PFK tyrosine residues in skeletal muscle, an important mechanism of the enzyme activation. Moreover, lactate indirectly inhibited HK activity, which resulted from its cellular redistribution, here attributed to alterations of HK structure. PK activity was not affected by lactate. The activity of HK and PFK is directly related to glucose metabolism. Thus, it is conceivable that lactate exposure can induce inhibition of glucose consumption in tissues.
我们研究了乳酸对不同小鼠组织中己糖激酶（HK）、磷酸果糖激酶（PFK）和丙酮酸激酶（PK）的酶活性的影响。结果表明，乳酸抑制了所有分析组织中的 PFK 活性。即使在胰岛素存在的情况下，这种抑制作用也存在于骨骼肌中。乳酸直接抑制了骨骼肌中 PFK 酪氨酸残基的磷酸化，这是酶激活的重要机制。此外，乳酸通过其细胞再分布间接抑制了 HK 的活性，这归因于 HK 结构的改变。PK 活性不受乳酸影响。HK 和 PFK 的活性与葡萄糖代谢直接相关。因此，可以想象，乳酸暴露可能会导致组织中葡萄糖消耗的抑制。
