镉对河南华溪蟹副性腺组织的氧化性损伤作用

为了探明慢性镉胁迫对河南华溪蟹(Sinopotamon henanense)副性腺的生殖毒性作用,实验设置了2个镉浓度组(0.725和1.45 mg·L-1)、1个对照组、3个处理时间(7、14和28 d),研究了镉在副性腺组织的积累,以及镉对副性腺组织细胞结构、抗氧化酶,如超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)活性及脂质过氧化水平(MDA含量)、蛋白质羰基化(PCO含量)和DNA-蛋白质交联(DPC)的影响.结果显示,镉处理后在河南华溪蟹副性腺组织中的积累显著或极显著高于对照组,且随着时间的延长和镉浓度的增加,副性腺组织镉的积累逐渐增高;副性腺组织细胞结构发生了不同程度的改变,主要表现为上皮细胞与基膜分离甚至破裂导致细胞核丢失.镉浓度0.725和1.45 mg·L-1条件下处理28 d,基膜结构发生明显改变,上皮细胞和基膜之间出现较大空腔,上皮细胞细胞核变形.SOD和GPx活性先升后降,而CAT的活性则随着镉浓度的增加逐渐升高;PCO含量和DPC均随着时间的延长和浓度的增加而显著升高;MDA含量也呈明显的升高趋势,但在28 d有所下降.表明慢性镉胁迫对河南华溪蟹副性腺产生了明显的氧化损伤,可能会影响副性腺正常的生理功能.

Effects of cadmium on the male accessory gland of the freshwater crab Sinopotamon henanense

To explore the reproductive toxicity of chronic cadmium (Cd²⁺) stress on the male accessory gland of the freshwater crab Sinopotamon henanense, this study set up two Cd²⁺ concentration groups (0.725 and 1.45 mg· L^-1) and one control group for three treatment times (7, 14 and 28 d), and investigated the tissue accumulation of Cd²⁺ and the effects of Cd²⁺ on the microstructure, the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and the contents of malonyldialdehyde (MDA), protein carbonyl (PCO) and DNA-protein crosslinks (DPC) in the male accessory gland. The results showed that the tissue accumulation of Cd²⁺ after treatment was significantly higher than the control group. With the increase of time and Cd²⁺ concentration, the accumulation of Cd²⁺ increased gradually. The microstructure of the accessory gland changed in different degrees, and epithelial cells were separated from basement membrane or even ruptured, causing nucleus lost. Notably in the two Cd²⁺ concentration groups on 28 d, the structure of basement membrane changed seriously, and larger cavity appeared between epithelial cells and basement membrane with serious nucleus lost in epithelial cells. The activities of SOD and GPx increased initially and then decreased, while the activity of CAT increased as the concentration of Cd²⁺ increased. The PCO content and DPC in the tissues increased significantly in a time-and concentration-dependent manner. The content of MDA also showed an increasing trend, but decreased on the 28 d. The results suggested that the chronic Cd²⁺ stress caused oxidative damages on the male accessory gland of S. henanense, which may affect its physiological functions.