Feces copper

Copper is an essential trace element. It is required in the diet because it is the metal cofactor for a variety of enzymes (see Table 50—5). Copper accepts and donates electrons and is involved in reactions involving dismu-tation, hydroxylation, and oxygenation. However, excess copper can cause problems because it can oxidize proteins and hpids, bind to nucleic acids, and enhance the production of free radicals. It is thus important to have mechanisms that will maintain the amount of copper in the body within normal hmits. The body of the normal adult contains about 100 mg of copper, located mostly in bone, liver, kidney, and muscle. The daily intake of copper is about 2—A mg, with about 50% being absorbed in the stomach and upper small intestine and the remainder excreted in the feces. Copper is carried to the liver bound to albumin, taken up by liver cells, and part of it is excreted in the bile. Copper also leaves the liver attached to ceruloplasmin, which is synthesized in that organ. 

Adults require 1-2 mg of copper per day, and eliminate excess copper in bile and feces. Most plasma copper is present in ceruloplasmin. In Wilson s disease, the diminished availability of ceruloplasmin interferes with the function of enzymes that rely on ceruloplasmin as a copper donor (e.g. cytochrome oxidase, tyrosinase and superoxide dismutase). In addition, loss of copper-binding capacity in the serum leads to copper deposition in liver, brain and other organs, resulting in tissue damage. The mechanisms of toxicity are not fully understood, but may involve the formation of hydroxyl radicals via the Fenton reaction, which, in turn initiates a cascade of cellular cytotoxic events, including mitochondrial dysfunction, lipid peroxidation, disruption of calcium ion homeostasis, and cell death. 

Retention of radiocopper injected into humans is high only 10% is excreted within 72 h in urine and feces, and 50% in four weeks (Aaseth and Norseth 1986). Most (72%) of the unabsorbed copper is excreted in the feces primarily by way of the biliary duct, the salivary glands, or the intestinal mucosa a minor portion is excreted by way of sweat and menses (Schroeder et al. 1966 USEPA 1980 ATSDR 1990). In mammals, copper is excreted mainly via the bile in association with glutathione or unidentified high-molecular-weight molecules. However, the transport mechanisms of copper from liver cells into bile are essentially unknown (Aaseth and Norseth 1986). In rats, biliary excretion of copper is increased by increased flow of bile, increased body temperature, or administration of adrenal steroids (Sugawara et al. 1994). 

Maximum concentrations of copper in elasmobranchs and teleosts from all collection sites range from 7 to 15 mg/kg DW in eyeballs, intestines, muscle, scales, vertebrae, heart, and gonads and from 16 to 48 mg/kg DW in gills, kidneys, skin, and spleens. They reach 53 mg/kg DW in whole animals, 155 mg/kg DW in stomach contents, 208 mg/kg DW in feces, and 245 mg/kg DW in livers (Table 3.3). 

Increasing dietary Mo resulted in decreasing copper retention due to increasing excretion of copper in feces up to 1.45 g Mo/kg BW absorbed and retained with no obvious adverse... 

The effects of leucaena and mimosine on nonruminants can be reduced to some extent by diet supplementation with ferrous sulfates. Mimosine forms a complex with iron, which is excreted in the feces. Zinc supplementation has reduced the toxicity in cattle and it is believed that copper and zinc ions bind more strongly to mimosine than most other amino acids. 

Table I. These are the amounts fed at the 2800-calorie level. Caloric intake was adjusted to the individual needs of the subjects by increasing or decreasing all foods the appropriate percentage to maintain each subject s weight during the study. Carbohydrate, fat, and protein made up 50, 37, and 13% of the total calories, respectively. The low fiber diet was supplemented with carotene, iron, magnesium, and copper in an attempt to make the two diets equivalent in all respects except fiber. During the last 7 days of each 26-day period, the subjects collected all urine and fecal sauries. Feces were marked by giving each subject 50 mg Brilliant blue. Seven-day cotqiosites of food, urine, and feces were prepared. Neutral detergent fiber (NDF) intake was 5 and 25 g/day on the low and higher fiber diets, respectively (18).

The trace elements iron, copper, zinc, and manganese, however, are excreted via the feces. Not only do the insoluble and unabsorbed dietary metals pass through the gastrointestinal tract, but also continual sloughing off of intestinal cells removes significant amounts of metal from the organism. 

Despite these difficulties the use of the silica gel technique for the solid probe/quadrupole mass spectrometer system holds promise for the analysis of some nutritionally important metals Both zinc and copper have been extracted successfully from serurn and zinc has also been extracted from urine and feces by using an anion exchange purification Biorad A61X8 (100-200 mesh) chloride form) anion exchange resin has been used to separate copper and zinc from acidic solutions (6) We have adapted this method to the separation of these two metals from acidic solutions of AAS standards urine serum and deproteinated fecal homogenate by elution with sucessively dilute acid solutions Recovery of an isotopic spike ai subsequent mass spectral analysis has been demonstrated with a Zn spike added to 1ml aliquots of a Fisher Certified AA Standard (zinc concentration Img/ml) Results of this experiment are shown in Table III ... 

Preparation of Chelates The procedure we use is adapted from that used by Hui et al ( ) to measure copper in rat brain Samples of feces approximately 0 25 g were ashed in a low temperature asher dissolved in concentrated HC1 and applied to Bio-Rad AG-1 anion exchange columns [Mention of a trademark or proprietary produce does not constitute a guarantee or warranty of the product by the U S Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable ] The various metals were then separated by elution with successively lower concentrations of HCl Recovery of metals from the columns was 97 6+2 7% for Fe, 10(H 2% for Cu, and 93 7+1 8% for Zn Each metal fraction was then refluxed separately with TPP in dimethylformamide to form the metal chelate ( ) ... 

Gregus and Klaassen carried out a comparative study of fecal and urinary excretion and tissue distribution of eighteen metals in rats after intravenous injection. Total (fecal + urinary) excretion was relatively rapid (over 50% of the dose in 4 days) for cobalt, silver and manganese between 50 and 20% for copper, thallium, bismuth, lead, cesium, gold, zinc, mercury, selenium and chromium and below 20% for arsenic, cadmium, iron, methylmercury and tin. Feces was the predominant route of excretion for silver, manganese, copper, thallium, lead, zinc, cadmium, iron and methylmercury whereas urine was the predominant route of excretion of cobalt, cesium, gold, selenium, arsenic and tin. Most of the metals reached the highest concentration in liver and kidney. However, there was no... 

The normal range of serum copper in the adult is 11 to 24 Urinary copper is normally about 20 jjg/day. This level is equivalent to 0.5 to 3.0% of copper intake. Most of the copper absorbed into the body is excreted by way of the bile and lost via the feces. About 1.7 mg of copper is excreted in bile per day this amount varies with the amount absorbed from the diet. This copper occurs complexed with protein and bilirubin. Bilirubin is a catabolite of heme. The copper is excreted in the bile and lends not to be absorbed back Into the body, There is little or no enterohepatic circulation of copper. The concentration of bile copper drops markedly with a copper deficiency, contributing to the conservation of this mineral by the body. 

Molybdenum is very efficiently absorbed, in contrast, for example, to copper and iron. With doses of 0-025—1,4 mg Mb, only 1% of the mineral is recovered in the feces. With a single dose of a low level of the mineral (<0.025 mg), about 20% of the mineral is recovered in the urine during a 6collection period. With a large test dose (1.4 mg), about 90% of the dose is recovered in a six day period (Tumlund et fli., 1995). 

Between 0.5 and 2.0 mg of copper per day is excreted via bile into feces. Patients with cholestatic jaundice or other forms of hver dysfunction are therefore at risk of copper accumulation caused by failure of excretion. Copper losses in urine and sweat are <3% of dietary intalce. Urine copper output is normally less than 60pg/day. 

The main route of excretion of copper from the body is via the feces. Urine contains extremely small amounts of copper (4-30 ig/day in man) (B33). Sweat contains only negligible quantities (M26). There is very little copper in saliva, and it is recirculated. Insignificant amounts are lost by menstruation (L6). 

Two studies discuss the acute absorption of radiolabeled maneb in rodents. The first study (Brocker and Schlatter 1979) used unfasted adult female rats dosed with [ " Mnjmaneb at a dose of 4-10 mg/kg. The rats were kept in metabolism cages which allowed the collection of respired air, urine, and feces for several hours post-dosing. The maneb was given alone or in conjunction with different metal compounds. Radioanalysis of excreta and selected tissues revealed that at 72 hours post-dosing, only 4-6% of the radioactivity was retained in the body with the majority of the label located within the liver and kidney. For 2 different chemical preparations of maneb, the recovery of label in feces was 94-96%, with the remainder in the urine. The respired air of two rats contained only 0.24 and 0.60% of the label, respectively. When molar excesses of the chloride salts of zinc, copper, iron, and mercury were added with the maneb. 

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