Zoology Department, Faculty of Science, Assiut University, 71516, Assiut, Egypt.
Zoology Department, Faculty of Science, Al Azhar University, 71524, Assiut, Egypt.
Fish Physiol Biochem. 2010 Sep;36(3):605-626. doi: 10.1007/s10695-009-9334-6. Epub 2009 Jul 17.
Many ultraviolet-A (UVA)-induced biochemical and physiological changes are valid as biomarkers using aquatic species for detection of the degree of stress. Changes in the concentration and activities of enzymes, such as glucose-6-phosphate dehyderogenase (G6PDH), lactate dehyderogenase (LDH), DNA damage and lipid peroxidation (LPO), can be used as biomarkers to identify possible environmental contamination in fish. This study aimed to investigate the impact of UVA on the activity of the selected enzymes, DNA damage and LPO during early developmental stages of the African catfish Clarias gariepinus. Embryo hemogenates were used for measurements of G6PDH, LDH, DNA damage and LPO concentrations and activities spectrophotometrically at 37 degrees C. The normal ontogenetic variations in enzyme activities, DNA damage and LPO of the early developmental stages (24-168 h-PFS; hours-post fertilization stage) were studied. There was a significant decrease in the activity of G6PDH till 120 h-PFS. Then after 120 h-PFS, the activity of such enzymes insignificantly increased toward higher stages. The LDH activity was recorded with a pattern of decrease till 96 h-PFS, followed by a significant increase toward 168 h-PFS. The polynomial pattern of variations in DNA damage and LPO was also evident. The patterns of the enzyme activities, corresponding DNA damage and LPO of the early ontogenetic stages under the influence of three different UVA doses (15, 30 and 60 min), were recorded. The pattern of variations in G6PDH activity in UVA-induced groups was similar to that of the control group with variation in the magnitude of such activity. In all treated groups, LDH activity decreased till 96 h-PFS, then increased till 168 h-PFS. Within each of the embryonic stages, the increase in UVA led to a significant increase in DNA damage. A significant increase in lipid peroxidation under UVA doses was recorded. The variability in number and molecular weight of proteins under exposure to UVA was evident, reflecting some of the genetic and transcriptional changes during exposure and development.
许多紫外线-A（UVA）诱导的生化和生理变化可作为生物标志物，用于检测水生物种的应激程度。酶浓度和活性的变化，如葡萄糖-6-磷酸脱氢酶（G6PDH）、乳酸脱氢酶（LDH）、DNA 损伤和脂质过氧化（LPO），可作为生物标志物，以识别鱼类中可能存在的环境污染。本研究旨在探讨 UVA 对非洲鲶鱼（Clarias gariepinus）早期发育阶段选定酶、DNA 损伤和 LPO 活性的影响。胚胎血淋巴用于在 37°C 下分光光度法测量 G6PDH、LDH、DNA 损伤和 LPO 浓度和活性。研究了早期发育阶段（24-168 h-PFS；受精后阶段）酶活性、DNA 损伤和 LPO 的正常个体发育变化。在 120 h-PFS 之前，G6PDH 活性显著下降。之后，在更高的阶段，这些酶的活性会轻微增加。LDH 活性呈下降趋势，直到 96 h-PFS，然后在 168 h-PFS 时显著增加。DNA 损伤和 LPO 的变化呈多项式模式。在三种不同 UVA 剂量（15、30 和 60 分钟）的影响下，记录了早期个体发育阶段的酶活性、相应的 DNA 损伤和 LPO 的模式。在 UVA 诱导组中，G6PDH 活性的变化模式与对照组相似，只是这种活性的变化幅度不同。在所有处理组中，LDH 活性在 96 h-PFS 之前下降，然后在 168 h-PFS 之前增加。在每个胚胎阶段，UVA 的增加都会导致 DNA 损伤的显著增加。在 UVA 剂量下，脂质过氧化的显著增加得到了记录。在暴露于 UVA 下，蛋白质的数量和分子量的变化是明显的，反映了暴露和发育过程中的一些遗传和转录变化。
