Nutritive metal uptake in teleost fish

Abstract

Transition metals (i.e. copper, zinc, iron, cobalt, selenium, manganese) are essential for the health of most organisms, forming integral components of proteins involved in all aspects of biological function. Their ubiquity is governed by their ability to form a wide range of coordination geometries and redox states, which allows these elements to interact with many cellular entities, performing pivotal roles in cellular respiration, oxygen transport, protein stability, free radical scavenging, and the action of many cellular enzymes, as well as for DNA transcription. However, in excess they are toxic, binding to inappropriate biologically sensitive molecules or forming dangerous free radicals. Consequently, there is a fine balance between metal deficiency and surplus and it is vital for organisms to maintain metal homeostasis via balancing absorption and excretion.Fish are unique among the vertebrates, a consequence of having two routes of metal acquisition, from the diet and from the water. This review will focus on the uptake processes present in the gill and intestinal epithelium of teleost fish for the three most abundant nutritive metals: iron, copper and zinc. The majority of the available literature concerns metal uptake processes in freshwater teleosts, but where appropriate examples exist, information on seawater teleosts will be reviewed. Molecular evidence indicates that transporters for these metals identified in yeast, plants or mammals all show high sequence homology in key functional regions ), but to date, none of these transporters have been characterised in fish. However, due to the evolutionary conservation of these proteins between yeast, plants and mammals, it is envisaged that fish metal transporters will also belong to the large iron, copper or zinc metal transporter protein families already identified. This review will combine physiological and molecular data to provide an overview of metal uptake mechanisms in teleost fish. IronIron is an essential nutrient to almost all organisms. Iron positioning in the haem moiety of haemoglobin increases oxygen binding and carrying capacity, enabling oxygen transfer to all tissues in multicellular organisms. One of iron's key cellular functions is to confer redox activity to the cytochromes involved in respiration, due to its ability to exchange electrons in aerobic conditions. A negative consequence of iron's redox flexibility is that it produces oxygen free radicals that are toxic to the cell. Consequently, in excess, iron can be detrimental to health. In addition, excess waterborne iron may be toxic to fish, due to the formation of iron 'flocs' on the gills, resulting in gill clogging and respiratory perturbations (Peuranen et al., 1994;Dalzell and MacFarlane, 1999). Teleost fish iron homeostasisThe iron content of fish is, in general, considerably lower than that of other vertebrates (Van Dijk et al., 1975), but the precise daily iron requirements for fish are at present unknown. 11The Journal of Experimental Biology 206, 11-23 © 2003 The Compa...

Monitoring of trace metals, biochemical composition and growth of Axillary seabream (Pagellus acarne Risso, 1827) in offshore Copper alloy net cage

“…No organic growth was observed on Copper alloy mesh material used in the present study over its full 180-day duration. Underwater monitoring showed a good fish condition with no disease symptoms, possibly due to a more sanitary environment and reduced stressful conditions in the cage, which is an important sign for improved fish welfare as also reported by Yigit et al (2013) Burry et al (2003) reported that copper has a role as a co-factor for a number of key proteins such as dopamine hydroxylase, cytochrome oxidase, superoxide dismutase, and ceruloplasmin. Similar to Iron, the flexible redox state of copper shows that it plays an important role in cellular respiration with cytochrome c oxidase as an important copper protein.…”

“…Similar to copper, zinc is also known as an essential element due to its vital structural or catalytic importance in over 300 proteins, playing important roles on fish growth and reproduction, as well as on the immune system (Watanabe et al, 1997;Burry et al, 2003). Previous studies, reported zinc levels around 56.3 mg kg -1 in the muscle tissues of gilthead seabream Sparus aurata from Black Sea and the Aegean Sea (Uluozlu et al, 2007), and between 4.49-11.6 mg kg -1 in muscle tissues of gilthead seabream, Sparus aurata from Marmara, Aegean and the Mediterranean sea (Türkmen et al, 2009).…”

“…With the presence of iron in the haem moiety of hemoglobin improves oxygen binding andcarrying capacity for the oxygen transfer to the tissues of the organisms. A negative consequence of iron's redox flexibility is its production of oxygen free radicals which are toxic to the organism (Burry et al, 2003). Excess iron levels in the tissues can be toxic and may have negative effects on fish health (Dalzell & MacFarlane, 1999).…”

Environmental Contaminants in Fish and Their Associated Risk to Piscivorous Wildlife in the Yukon River Basin, Alaska

“…Concentrations of Zn were greater in sucker from Station 301 than from Stations 306 and 308 (Table 5). Zinc is highly regulated in fish (Bury et al 2003), and few studies have measured Zn concentrations in whole-body fish (Jarvinen and Ankley 1999). Zinc concentrations in most pike were >40 lg/g, a concentration that has been associated with reduced growth and survival in larval and adult cyprinids (Spehar 1976).…”

Sucul Organizmalarda Çevresel Şartlara Karşı Geliştirilen Oksidatif Stres Mekanizmaları ve Adaptif Yanıtlar

“…Sucul canlılarda demir metabolizması ve fonksiyonları diğer organizmalara benzer şekildedir. Örneğin, balıklar demiri solungaç epitellerinden geçen sularla ve besinler ile alabilirler [35,36]. Demirin yaşamsal süreçte temel unsur olduğu bilinmektedir.…”