Prasada Rao P V, Jordan S A, Bhatnagar M K
Ontario Veterinary College, University of Guelph, Canada.
J Toxicol Environ Health. 1989;26(3):327-48. doi: 10.1080/15287398909531257.
This report describes the metallothionein (MT) levels and accumulation of mercury, lead, and cadmium, as well as their interaction with tissue zinc, copper, and iron, and the histopathological changes in kidneys of ducks exposed to methylmercury chloride (MeHgCl), lead acetate (PbAc), and cadmium chloride (CdCl2), singly or in combination for 13 wk. Forty-eight female Pekin ducks, divided into 8 groups of 6 birds each, were fed diets containing no added metals (control), 8 mg MeHgCl/kg feed, 80 mg PbAc/kg feed, 80 mg CdCl2/kg feed, 8 mg MeHgCl + 80 mg PbAc/kg feed, 8 mg MeHgCl + 80 mg CdCL2/kg feed, 80 mg PbAc + 80 mg CdCl2/kg feed, and 8 mg MeHgCl + 80 mg PbAc + 80 mg CdCL2/kg feed. Cadmium (Cd) when administered alone or in combination caused a 60-fold increase in kidney MT levels, while methylmercury (MeHg) or lead (Pb) administration caused a threefold increase in kidney MT levels. No significant changes in kidney MT levels were observed when metals were administered concurrently when compared with single-treatment groups. Residue analysis revealed accumulation of administered metals in kidney tissue. However, lead administration resulted in accumulation of small amounts of this element in kidney tissue. Simultaneous administration of MeHgCl and PbAc significantly increased the accumulation of lead in kidney when compared with PbAc-treated group. Cadmium when administered alone or in combination caused an increase in the levels of zinc and copper in kidney. Administration of MeHgCl or PbAc either alone or in combination caused increased iron levels in kidney, while cadmium administration either alone or in combination caused decreased iron levels. Administration of cadmium either alone or in combination caused degenerative changes in kidney proximal tubules. The severity of degenerative lesions increased when cadmium was simultaneously administered with other metals. These results indicate that combined administration of MeHg, Pb, and Cd has no significant effect on kidney MT levels or on essential elements in kidney tissue when compared with single metal groups. However, there appears to be an increase in the severity of histopathologic changes.
本报告描述了金属硫蛋白（MT）水平以及汞、铅和镉的蓄积情况，及其与组织锌、铜和铁的相互作用，以及单独或联合暴露于氯化甲基汞（MeHgCl）、醋酸铅（PbAc）和氯化镉（CdCl2）13周的鸭肾脏的组织病理学变化。48只雌性北京鸭，分为8组，每组6只，分别喂食不添加金属的饲料（对照组）、含8 mg MeHgCl/kg饲料、含80 mg PbAc/kg饲料、含80 mg CdCl2/kg饲料、含8 mg MeHgCl + 80 mg PbAc/kg饲料、含8 mg MeHgCl + 80 mg CdCL2/kg饲料、含80 mg PbAc + 80 mg CdCl2/kg饲料以及含8 mg MeHgCl + 80 mg PbAc + 80 mg CdCL2/kg饲料的日粮。镉单独或联合给药导致肾脏MT水平增加60倍，而甲基汞（MeHg）或铅（Pb）给药导致肾脏MT水平增加三倍。与单一组相比，同时给药时未观察到肾脏MT水平有显著变化。残留分析显示给药金属在肾脏组织中蓄积。然而，铅给药导致该元素在肾脏组织中少量蓄积。与醋酸铅处理组相比，同时给予氯化甲基汞和醋酸铅显著增加了肾脏中铅的蓄积。镉单独或联合给药导致肾脏中锌和铜水平升高。单独或联合给予氯化甲基汞或醋酸铅导致肾脏中铁水平升高，而单独或联合给予镉导致铁水平降低。单独或联合给予镉导致肾脏近端小管发生退行性变化。当镉与其他金属同时给药时，退行性病变的严重程度增加。这些结果表明，与单一金属组相比，甲基汞、铅和镉联合给药对肾脏MT水平或肾脏组织中的必需元素没有显著影响。然而，组织病理学变化的严重程度似乎有所增加。
