Zinc toxicity

About: Zinc toxicity is a research topic. Over the lifetime, 727 publications have been published within this topic receiving 34583 citations. The topic is also known as: zinc poisoning.

Dietary Taurine Reduces Zinc-Induced Toxicity in Male Wistar Rats

Abstract: Taurine is an agent for treating the heavy metal intoxication and presence of metals such as zinc, copper, and iron may have a role in heavy metal toxicity, a study was undertaken to investigate the effect of taurine on the toxicity of zinc in male Wistar rats. The rats were divided into 8 groups and fed different diets with or without supplement of 5% taurine and 150 to 600 ppm zinc for 2 mo. It was found that the body weight of rats, the ratios of liver and kidney weight to body weight, and the level of glutathione in the liver were decreased with increasing the dose of zinc. The levels of zinc in the liver, kidney, and plasma, the levels of malondialdehyde in the plasma, the levels of thiobarbiture acid-reactive substances in the liver, the activities of aspartate transaminase, alanine transaminase in the plasma, the levels of blood urea nitrogen and creatinine in the plasma of rats were increased with the increasing dose of zinc. Hence, symptoms of zinc toxicity in rats included loss of body weight, hepatotoxicity, and nephrotoxicity. However, these toxic effects of zinc were significantly reduced when the rats fed diet with supplement of taurine. Furthermore, the level of zinc in the feces of rats treated with taurine and zinc was higher than that of rats treated with zinc alone. It indicated that taurine thereby leading to a decreased absorption of dietary zinc and promoted excretion.

Hair zinc levels in pet and feral cats (felis catus)

Abstract: Zinc is an essential element for maintaining proper functions of animal bodies. It is a component of many hormones and enzymes and a participant in the metabolism of carbohydrates or the synthesis of nucleic acids and proteins. Animal tissues typically contain 10-200 mg of zinc kg–1. Most of this amount (98%) can be found inside the cells. Zinc toxicity is associated mainly with the secondary copper deficit. The aim of the present investigation has been to assess zinc contamination of the environment with coats of domestic and feral cats being the indicator. Urban feral cats are synantrophic animals, living in an urbanized environment and scavenging on human food waste. Thus, they can be treated as a bioindicator of the presence of certain elements in the environment. Analyses of the zinc content in cats’ hair have been performed to check whether the zinc level is connected with cats’ coat colour, living conditions and gender. The coat samples were collected from the middle abdominal region. Then they were degreased and mineralized in a microwave apparatus, in concentrated nitric acid under increased pressure. The zinc content was determined by the ICP-OES method. The mean zinc content in the investigated coat samples was 238.9 mg kg –1 . The lowest zinc content was observed in white hair and the highest – in tortoiseshell hair. The results have confirmed that the content of zinc depends on the hair saturation with melanin. Statistical analysis has shown significant differences between the group of female cats living in the wild (268.09 mg kg–1) and the group of breeding female cats (214.49 mg kg–1) at p=0.05. A higher zinc content was observed in the group of older cats. The mean values did not differ from mean values of the zinc content in the coat and hair of other mammals. Considering the living conditions of the animals, the highest zinc content was noted in the group of animals living in the wild (feral ones).

Studies on zinc toxicity in the larvae of the rice moth, Corcyra cephalonica St.

Abstract: Zinc salts fed at relatively high concentrations in the diet have been known to produce deleterious effects. Sutton & Nelson (1938) found that 1 % of zinc as carbonate impaired the growth and general health of rats. Smith & Larson (1946) were, however, the first to study extensively this phenomenon in rats. They established that this condition manifested itself in the following two distinct and unrelated symptoms: (a) an anaemia, of the microcytic, hypochromic type, and (b) an inhibition of growth. The former syndrome could be prevented by supplementing the diet with low levels of copper, and liver extract could partially reverse the adverse influence on growth. van Reen (1953) found that at the 0-5-0-7 % level, zinc reduced liver catalase and cytochrome oxidase and that copper could counteract this influence of zinc. These studies indicated that toxic levels of zinc interfere with the utilization of copper and thus indirectly with the formation of iron-containing enzymes. van Reen & Pearson (1953) concluded, however, that the toxicity of zinc was not primarily due to disturbances in these enzyme levels. Such a conclusion is supported by the fact that serious impairement of growth occurs before reduction in any of the enzymes studied. Thus the underlying mechanisms in zinc toxicosis are not fully known. The situation is complex and although the studies of Smith & Larson (1946) have shown that liver extract is beneficial in zinc toxicosis, the factors responsible have not been characterized, nor is anything known concerning zinc toxicity in other species. In this paper, the results of investigations on zinc toxicity in the lepidopterous insect Corcyra cephalonica St. are presented. Although this organism is much lower in the evolutionary scale, it shows striking similarities (Sarma, 1955) to higher organisms like the rat in its nutritional requirements and metabolism.