Normal Concentrations of Some Trace Metals in Human Urine: Changes Produced by Ethylenediaminetetraacetate *

Abstract

Interest in the biologic role of trace elements prompted an investigation of their renal excretion. Preliminary qualitative analysis revealed that except for cobalt the entire first transition series of metals, namely, titanium, vanadium, chromium, manganese, iron, nickel and copper, were detectable in most human urines. In addition the heavier transition metals, molybdenum and silver, as well as the related metals, zinc, cadmium, tin and lead, were ordinarily present. A method was evolved by which the urinary concentrations of such metals could be quantitatively estimated. The procedure included initial chemical concentration followed by spectrographic analysis. Contamination was minimized by careful preparation of equipment and reagents. Since extraneous iron and copper were particularly difficult to avoid and since these two metals had frequently been studied by other techniques, no attempt was made to measure them spectrographically. The exclusion of significant positive contamination, the demonstration that the low renal excretion of cobalt permitted its use as an internal standard, and the determination of standard working curves and recovery data for each metal constituted the control data for the assay procedure. Estimations were less satisfactory for chromium and titanium than for the remaining nine metals.Collection and assay of 24 hour urines were performed in a standard manner. Such urines from normal persons served to indicate both the mean level and the variability of excretion for the nine trace metals which could be satisfactorily estimated. Daily differences in the renal excretion of metal as well as the effects produced by * Supported by grants-in-aid from the National Heart Institute of the United States Public Health Service, the American Heart Association, the Life Insurance Medical Research Fund and Abbott Laboratories.t Established Investigator, American Heart Association. extremes of urinary volume and pH were determined for 24 hour urines from one normal individual. A brief preliminary study was made of the metallic spectrum in single specimens of urine from hospitalized African natives. Finally, metal concentration was measured in consecutive 24 hour urines from hypercholesterolemic patients before, during and after the parenteral administration of the chelating agent, disodium calcium ethylenediaminetetraacetate, which had been observed to lower the level of cholesterol in human plasma (1). METHODSPrelimintary qutalitative uirinalysis. In order to select the metals to be assayed, 40 single urine specimens from different subjects were analyzed qualitatively. Half of. the samples were obtained from normal individuals and half from hospitalized patients with atherosclerosis and hypertension. The urines were evaporated to approximately one-twentieth of their original volume, after which most of the organic material was oxidized with hydrogen peroxide. The residues were then dried, mixed with an approximately equal amount of graphite, and burned to completion in a direct current arc. The ph...

Effects of an EDTA infusion on the urinary elimination of several elements in healthy subjects.

“…The 24 h excretion of Na, K, Ca, Mg is well documented and our values are in the same range as those reported, for example, by Staessen et al (1983). The increased urinary elimination of Pb, Mn and Zn after EDTA Ca Na2 infusion is well-documented (Perry & Perry, 1959). In addition, we have now shown that the elimination of Fe and Al is also increased.…”

“…(1986) (10 pg 24 h-1). The high mean concentration of 120 ,ug 1-1 obtained in normal Americans (Perry & Perry, 1959) can be explained by the insufficient sensitivity of the spectrographic method used at that time.…”

“…Although it is in widespread use its effects on the urinary elimination of elements in healthy subjects have not been studied systematically. Early investigations were carried out in patients (Perry & Perry, 1959) as were more recent studies in lead poisoned children (Chilsom, 1968).…”

Health hazard evaluation report: HETA-83-222-1631, Metz Metallurgical, South Plainfield, New Jersey.

“…Urine silver levels in an unexposed group are reported to average 1.61 ug/liter with a standard error of the me~n of 0.15 (9). We have adopted an upper limit of normal for unexposed groups as the mean plus two standard errors, or 1.91 ug/l.…”

Metabolism of radiocaesium during gestation and lactation as influenced by ferric-cyanoferrate (II)

“…Which metal(s) and which biological constituents are actuaIIy involved, however, is an open question. AIthough the Ca-ehelates lead to a marked zincuria, whereas the exeretion of other trace metals is infl.uenced, if at aII, to a lesser degree (Bohne et al, 1967a;Candura et al, 1960;MilIar et al, 1954;Perry and Perry, 1959;Spencer and Rosoff, 1966;Tarui, 1960;Truhaut et al, 1966), the pathogenetic relevance of these findings, however, is not yet fuIIy understood. Our experimental contribution is eoneerned with same quantitative aspects of the interaction between chelating agents and endogenaus Zn.…”