Almeida J A, Novelli E L, Dal Pai Silva M, Júnior R A
University Estadual Paulista, UNESP, Botucatu, São Paulo, Brazil.
Environ Pollut. 2001;114(2):169-75. doi: 10.1016/s0269-7491(00)00221-9.
The contamination of water by metal compounds is a worldwide environmental problem. This study was undertaken to evaluate the impact of short-term cadmium exposure on metabolic patterns of the freshwater fish Oreochromis niloticus. The fish were exposed to 320, 640, 1,280 and 2,560 microg/l sublethal concentrations of Cd++ (CdCl2) in water for 7 days. The specific activities of the enzymes phosphofructo kinase (PFK-E.C.2.7.1.11.), lactate dehydrogenase (LDH-E.C.1.1.1.27.) and creatine kinase (CKE.C.2.7.3.2.) were decreased in white muscle after cadmium treatments, indicating decreases in the capacity of glycolysis in this tissue. Cadmium exposure induced increased glucose concentration in white muscle of fish. On the other hand, cadmium exposure at sublethal concentrations increased phosphofructo kinase and LDH in red muscle of fish. Cadmium significantly decreased total protein concentrations in liver and white muscle regardless of tissue glycogen levels. The data suggest that cadmium acts as a stressor, leading to metabolic alterations similar to those observed in starvation.
金属化合物对水的污染是一个全球性的环境问题。本研究旨在评估短期镉暴露对淡水鱼尼罗罗非鱼代谢模式的影响。将鱼暴露于水中320、640、1280和2560微克/升的亚致死浓度Cd++（CdCl2）中7天。镉处理后，白肌中磷酸果糖激酶（PFK-E.C.2.7.1.11.）、乳酸脱氢酶（LDH-E.C.1.1.1.27.）和肌酸激酶（CK-E.C.2.7.3.2.）的比活性降低，表明该组织中糖酵解能力下降。镉暴露导致鱼白肌中葡萄糖浓度升高。另一方面，亚致死浓度的镉暴露会增加鱼红肌中的磷酸果糖激酶和乳酸脱氢酶。无论组织糖原水平如何，镉都会显著降低肝脏和白肌中的总蛋白浓度。数据表明，镉作为一种应激源，会导致类似于饥饿时观察到的代谢改变。
