The present study was performed to determine the effect of melatonin on cadmium accumulation and haematological parameters changes in females of Prussian carp (Carassius gibelio B.). The fish were exposed to a sublethal concentration of cadmium (0.4 and 4.0 mg/L) without or with melatonin implant (containing 18 mg melatonin hormone) for 1, 4, 7, 10 and 13 weeks. After the 7^th week, Cd-exposed fish were divided into two groups. The first group of fish were subjected to depuration in clear water, while the second group remained exposed to the same concentrations of cadmium. After the 10^th and 13^th weeks of exposure the kidney, spleen, heart and blood were taken in order to determine the cadmium concentration and to analyse haematological parameters. The results of this study showed an increase in the concentration of cadmium in the tissues and blood in fish exposed to the highest dose (4.0 mg/L) of cadmium in water with a dependence on the exposure duration. Additionally, it was shown that melatonin administration reduced the cadmium concentration in the tissues and blood, and melatonin had a protective effect against cadmium accumulation. Moreover, the results showed a significant increase in blood parameters (RBC, Ht and Hb) in fish treated with the highest dose of cadmium. However, implantation of melatonin in cadmium-treated fish resulted in marked improvements in haematological parameters. Thus, melatonin can be a good implementation to alleviate, at least partially, the toxicity of cadmium.

中文翻译：

---

褪黑素对镉中毒普鲁士（鱼中镉积累和血液学参数的影响

本研究旨在确定褪黑素对普鲁士鲤鱼（Carassius gibelio B.）雌性中镉积累和血液学参数变化的影响。将鱼暴露于亚致死浓度的镉（0.4和4.0 mg / L）中，无论是否植入褪黑素（含有18 mg褪黑激素），持续1、4、7、10和13周。在经过7^个星期，镉暴露的鱼被分成两组。第一组鱼在纯净水中进行净化，而第二组鱼仍暴露于相同浓度的镉。在10^号和13^号之后接触肾脏，脾脏，心脏和血液的几周时间，以确定镉的浓度并分析血液学参数。这项研究的结果表明，暴露于水中最高剂量（4.0 mg / L）的镉的鱼体内组织和血液中的镉浓度增加，这取决于暴露时间。另外，已经表明，褪黑激素的施用降低了组织和血液中的镉浓度，并且褪黑激素具有对抗镉积累的保护作用。此外，结果显示，用最高剂量的镉处理的鱼的血液参数（RBC，Ht和Hb）显着增加。然而，褪黑素在镉处理过的鱼体内的植入导致血液学参数的显着改善。从而，