Faculty of Medicine, Institute of Medical Physiology "Richard Burian", University of Belgrade, Str. Visegradska 26/II, Belgrade, 11000, Serbia.
Department for Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia.
Mol Cell Biochem. 2018 Jul;444(1-2):143-148. doi: 10.1007/s11010-017-3238-z. Epub 2017 Nov 29.
The objective of this study was to investigate in vitro effects of 10 µM DL-homocysteine (DL-Hcy), DL-homocysteine thiolactone-hydrochloride (DL-Hcy TLHC), and L-homocysteine thiolactone-hydrochloride (L-Hcy TLHC) on the oxygen consumption of rat heart tissue homogenate, as well as the involvement of the gasotransmitters NO, HS and CO in the effects of the most toxic homocysteine compound, DL-Hcy TLHC. The possible contribution of the gasotransmitters in these effects was estimated by using the appropriate inhibitors of their synthesis (N -nitro-L-arginine methyl ester (L-NAME), DL-propargylglycine (DL-PAG), and zinc protoporphyrin IX (ZnPPR IX), respectively). The oxygen consumption of rat heart tissue homogenate was measured by Clark/type oxygen electrode in the absence and presence of the investigated compounds. All three homocysteine-based compounds caused a similar decrease in the oxygen consumption rate compared to control: 15.19 ± 4.01%, 12.42 ± 1.01%, and 16.43 ± 4.52% for DL-Hcy, DL-Hcy TLHC, or L-Hcy TLHC, respectively. All applied inhibitors of gasotransmitter synthesis also decreased the oxygen consumption rate of tissue homogenate related to control: 13.53 ± 1.35% for L-NAME (30 µM), 5.32 ± 1.23% for DL-PAG (10 µM), and 5.56 ± 1.39% for ZnPPR IX (10 µM). Simultaneous effect of L-NAME (30 µM) or ZnPPR IX (10 µM) with DL-Hcy TLHC (10 µM) caused a larger decrease of oxygen consumption compared to each of the substances individually. However, when DL-PAG (10 µM) was applied together with DL-Hcy TLHC (10 µM), it attenuated the effect of DL-Hcy TLHC from 12.42 ± 1.01 to 9.22 ± 1.58%. In conclusion, cardiotoxicity induced by Hcy-related compounds, which was shown in our previous research, could result from the inhibition of the oxygen consumption, and might be mediated by the certain gasotransmitters.
本研究的目的是研究 10μM 的 DL-高半胱氨酸（DL-Hcy）、DL-高半胱氨酸硫内酯盐酸盐（DL-Hcy TLHC）和 L-高半胱氨酸硫内酯盐酸盐（L-Hcy TLHC）对大鼠心肌组织匀浆耗氧量的体外影响，以及这些最毒的同型半胱氨酸化合物 DL-Hcy TLHC 中涉及的气体递质 NO、HS 和 CO 的作用。通过使用其合成的适当抑制剂（N-硝基-L-精氨酸甲酯（L-NAME）、DL-炔丙基甘氨酸（DL-PAG）和锌原卟啉 IX（ZnPPR IX），分别），估计了这些效应中气体递质的可能贡献。在不存在和存在所研究的化合物的情况下，通过 Clark/类型氧电极测量大鼠心肌组织匀浆的耗氧量。与对照相比，所有三种基于同型半胱氨酸的化合物均导致耗氧量相似的降低：分别为 15.19±4.01%、12.42±1.01%和 16.43±4.52%，用于 DL-Hcy、DL-Hcy TLHC 或 L-Hcy TLHC。所有应用的气体递质合成抑制剂也降低了与对照相关的组织匀浆的耗氧量：L-NAME（30μM）为 13.53±1.35%，DL-PAG（10μM）为 5.32±1.23%，ZnPPR IX（10μM）为 5.56±1.39%。L-NAME（30μM）或 ZnPPR IX（10μM）与 DL-Hcy TLHC（10μM）同时作用导致耗氧量的降低大于每种物质单独作用的降低。然而，当 DL-PAG（10μM）与 DL-Hcy TLHC（10μM）一起应用时，它将 DL-Hcy TLHC 的作用从 12.42±1.01 减弱至 9.22±1.58%。总之，我们之前的研究表明，同型半胱氨酸相关化合物引起的心脏毒性可能源于耗氧量的抑制，并且可能由某些气体递质介导。
