Andersson U, Leighton B, Young M E, Blomstrand E, Newsholme E A
Department of Biochemistry, University of Oxford, United Kingdom.
Biochem Biophys Res Commun. 1998 Aug 19;249(2):512-6. doi: 10.1006/bbrc.1998.9171.
Strips of rat soleus muscle were incubated in media containing a superoxide generating system and/or the nitric oxide donor sodium nitroprusside (SNP) before the maximal catalytic activities of aconitase, citrate synthase, and oxoglutarate dehydrogenase were measured. The maximal activities of aconitase and oxoglutarate dehydrogenase were both decreased by 25-30% by superoxide anions; however, only the maximal activity of aconitase was decreased, by approximately 50%, by incubation of muscles with SNP. Furthermore, when both superoxide and NO were present in the medium, aconitase activity was decreased by 70%. The maximal activity of citrate synthase was not affected by any of the treatments. This is the first time that superoxide anions or NO has been shown to inactivate aconitase and oxoglutarate dehydrogenase in skeletal muscle. It is suggested that these effects may be responsible for some alterations in skeletal muscle metabolism, and these possibilities are discussed.
在测定乌头酸酶、柠檬酸合酶和氧代戊二酸脱氢酶的最大催化活性之前，将大鼠比目鱼肌条在含有超氧化物生成系统和/或一氧化氮供体硝普钠（SNP）的培养基中孵育。超氧阴离子使乌头酸酶和氧代戊二酸脱氢酶的最大活性均降低了25%-30%；然而，仅用SNP孵育肌肉时，只有乌头酸酶的最大活性降低了约50%。此外，当培养基中同时存在超氧化物和一氧化氮时，乌头酸酶活性降低了70%。柠檬酸合酶的最大活性不受任何处理的影响。这是首次表明超氧阴离子或一氧化氮可使骨骼肌中的乌头酸酶和氧代戊二酸脱氢酶失活。有人认为，这些作用可能是骨骼肌代谢某些改变的原因，并对这些可能性进行了讨论。
