Abstract Hydrogen sulfide can both exert a toxic effect and function as a signaling molecule in various physiological processes. Under conditions of experimental short-term hydrogen sulfide loading (HSL), activities of oxidoreductases (enzymes of energy metabolism and antioxidant defense)—malate dehydrogenase (MDH, 1.1.1.37), lactate dehydrogenase (LDH, 1.1.1.27) and catalase (1.11.1.6) were analyzed in oxyphilic tissues (brain, heart, gills) of the Black Sea sea ruff Scorpaena porcus Linnaeus, 1758. Two groups of fish were exposed for 5 min to different concentrations of sodium sulfide (37 and 75 µM Na 2 S) used as a hydrogen sulfide donor. High MDH and LDH activities were simultaneously detected in the brain structures and heart chambers, reflecting a similar potential of energy metabolism in these tissues, while enhanced LDH activity in the brain indicated anaerobization of the energy metabolism pathways. Differences in oxydoreductase activities were found between the first and fourth branchial arches, heart atrium and ventricle, as well as between different brain compartments. Under HSL, the gills exhibited some signs of hypoxemia (increasing darkening of the lamellae as the Na 2 S concentration moved upward) and metabolic depression. At a low Na 2 S concentration, HSL did not cause significant changes in oxidoreductase activities in the brain and heart, while upon a 2-fold increase in the Na 2 S concentration these changes became more pronounced. In the key oxyphilic structures (anterior brain compartments, heart ventricle) intense HSL led to a simultaneous increase in LDH and MDH activities, which was due to the ability of MDH to participate in anaerobic processes. The less O 2 -sensitive structures (medulla oblongata and heart atrium) exhibited almost no changes in MDH and LDH activities even in response to high-intensity HSL, suggesting a different mode of energy metabolism in these tissues. Under intense HSL, the oxidoreductases in the heart ventricles and anterior brain compartments demonstrated responses, which were similar to those under hypoxia/anoxia.

中文翻译：

---

短期硫化氢负载下黑海蜈蚣嗜氧组织的氧化还原酶活性

摘要 硫化氢在各种生理过程中既可以发挥毒性作用，又可以作为信号分子发挥作用。在实验性短期硫化氢负载 (HSL) 条件下，氧化还原酶（能量代谢和抗氧化防御酶）的活性——苹果酸脱氢酶（MDH，1.1.1.37）、乳酸脱氢酶（LDH，1.1.1.27）和过氧化氢酶（1.11） .1.6) 在黑海海带 Scorpaena porcus Linnaeus，1758 年的嗜氧组织（大脑、心脏、鳃）中进行了分析。两组鱼在不同浓度的硫化钠（37 和 75 µM Na 2 S）中暴露 5 分钟)用作硫化氢供体。在大脑结构和心室中同时检测到高 MDH 和 LDH 活性，反映了这些组织中类似的能量代谢潜力，而大脑中 LDH 活性的增强表明能量代谢途径的厌氧化。在第一和第四鳃弓、心房和心室之间以及不同脑室之间发现氧化还原酶活性的差异。在 HSL 下，鳃表现出一些低氧血症的迹象（随着 Na 2 S 浓度向上移动，薄片变暗）和代谢抑制。在低 Na 2 S 浓度下，HSL 不会引起大脑和心脏中氧化还原酶活性的显着变化，而在 Na 2 S 浓度增加 2 倍时，这些变化变得更加明显。在关键的嗜氧结构（前脑室、心室）中，强烈的 HSL 导致 LDH 和 MDH 活性同时增加，这是由于 MDH 参与厌氧过程的能力。O 2 敏感性较低的结构（延髓和心房）即使在响应高强度 HSL 时也几乎没有表现出 MDH 和 LDH 活性的变化，这表明这些组织中存在不同的能量代谢模式。在强烈的 HSL 下，心室和前脑室中的氧化还原酶表现出反应，这与缺氧/缺氧下的反应相似。