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PubMed1990

[Absorption of chromium through the skin and urinary excretion in rats].

The aim of the experiment was to evaluate the diffusion rate in vitro and the skin absorption rate of trivalent and hexavalent chromium from aqueous solution. Excretion of chromium in urine was also measured. The experiment was carried out on 47 Wistar male rats, 4-5 months old. The solutions of chromium sulfate or potassium dichromate contained 2.5, 5.0 and 10.0 mg Cr per milliliter. Exposure time was 4 hrs. It was found that diffusion rate of Cr3+ was seven-time less than of Cr2O7(2-). Absorption rates of both ions through the skin were similar. Excretion rates of chromium in urine were not different in case exposure to both xenobiotics. It can be concluded that diffusion does not play an important role in absorption of chromium through the skin. It seems that oxidation grade of chromium has no influence on the excretion rate of this metal from the organism.

Animals↗
PubMed1973

Chromium in refined and unrefined sugars--possible nutritional implications in the etiology of cardiovascular diseases.

It has recently been discovered that chromium is an essential element, particularly in relation to carbohydrate metabolism. Food refinement leads to a loss of chromium as well as of other trace elements. The nutritional significance, particularly in relation to cardiovascular diseases, of the excessive consumption of refined food, poor in trace elements, is not well understood. The first results of a WHO study on the chromium content of different brands of refined and unrefined sugars obtained from various countries are described here. Flameless atomic absorption was used for chromium analysis. Molasses have the highest chromium content (0.266 mg/kg), followed by unrefined (0.162) and brown (0.064) sugars. Refined sugar has the lowest chromium content (0.020 mg/kg). No differences associated with the geographic origin of the sugars were observed.

Carbohydrates↗
PubMed1983

Exposure to chromium from hospital cleaning.

The relevance of a positive chromium patch test in females with hand eczema is very often obscure. In order to investigate the exposure to chromium in an everyday event as cleaning, the chromium content of water samples from various steps of the cleaning process in a Danish hospital was analyzed. During cleaning the chromium contamination increased above the theoretical limit necessary for sensitization. House dust contains considerable amounts of chromium, and will readily liberate it into suspension. All the chromium was found in the trivalent form.

Chromium↗
PubMed1978

Serum chromium and angiographically determined coronary artery disease.

Human aortas sampled from populations where there is little advanced atheromatous plaque formation contain higher concentrations of chromium than do aortas from populations in which atheromatosis is prevalent. In the present study serum cholesterol, triacylglycerols, and chromium (Cr3+) concentrations were measured in 32 subjects in whom coronary artery disease was assessed by cineangiography. The distribution of subjects with diseased and normal arteries overlapped below 5.50 microgram of chromium per liter. Only subjects free of coronary artery disease had chromium concentrations greater than or equal to 5.50 microgram/liter. The role of chromium was assessed in the context of the selected risk factors: cholesterol, triacylglycerols, and systolic and diastolic blood pressure. The group with coronary artery disease had significantly lower serum chromium concentrations than did the group with normally patent arteries.

Adult↗
PubMed1983

Biliary and gastrointestinal excretion of chromium after administration of Cr-III and Cr-VI in rats.

Rats treated intravenously with 51Cr-labelled sodium chromate, 0.1 or 100 microgram Cr/rat, excreted more 51Cr into bile in a 2-hr period than did the animals given equal amounts of chromium in the trivalent state. Distinct patterns of hepatic intracellular distribution of the radiotracer were also observed. In the Cr-VI rats over 50% of the liver chromium was present in the supernatant fraction whereas in the Cr-III rats almost all the liver radioactivity was localized in the cell organelles. Fractionation of bile on Sephadex G-75 demonstrated binding of chromium to low-molecular weight substances. It is suggested that complexes of chromium with low-molecular weight components of liver cytosol are involved in the passage of this element from the liver to bile. A low cytosolic content of diffusable Cr-complexes associated with the incorporation of a large fraction of liver chromium in cell organelles may be a factor contributing to the low rates of 51Cr biliary excretion in the animals given Cr-III. 24 hr after the injection of 51Cr to bile duct-ligated rats appreciable levels of radiotracer were found in the gastrointestinal tract. The animals given Cr-VI exhibited significantly higher values of chromium content in the gut than those treated with Cr-III.

Animals↗
PubMed1983

[Evaluation of exposure and of the biological effects in galvanic chromium plating by different technologies].

In the hard electroplating process, chromium exposure is heavier than in the bright process. The average urinary chromium was 9,7 +/- 7,2 micrograms/g cr. in the 31 bright plating subjects; comparing only the chromium bath workers of the two process, the difference was statistically significant (13,0 +/- 7,5 micrograms/g cr. against 7,6 +/- 4,4 micrograms/g cr. t = 2,4; p less than 0,0025). In a control group composed of 22 sanitary workers, the average urinary chromium was 1,9 +/- 1,4 micrograms/g cr. We found chromium rhinopathy in 40% of the hard process subjects and in 20% of the bright process subjects. Sputum cytologic examination was not correlated with the chromium level exposure. In the exposed workers we found 37% insufficient specimens and 53% metaplasia plus dysplasia; in the 42 control subjects we found 64% insufficient specimens, 33% metaplasia and no dysplasia.

Chromium↗
PubMed1996

[Is chromium an essential or a toxic element?].

Chromium holds a frequent and important place in toxicological literature. The large number of more or less important toxicological facts (e.g. allergic dermatoses, ulcer, perforations of the nasal septum, bronchitis, cancerogenity etc.) are the reason why chromium is conceived rather as a toxic element. On the other hand in the non-toxicological literature favourable actions of chromium are described (its relationship to carbohydrate utilization, the glucose tolerance factor, diabetes etc.) which may induce us to consider chromium an essential element. Is chromium toxic or essential? It is both. The concept of essential or toxic cannot be conceived statically, these terms are relative and depend on a number of other facts and data (dose, time, chemical form, individuality of the organism, interaction with other substances in the environment etc). This relative view has a more general validity not only for chromium but for trace elements in general and it is very important in particular with regard to prevention of health damage caused by deficiency or excess of a substance.

Chromium↗
PubMed1977

Urinary chromium excretion and atherosclerotic manifestations in two Finnish male populations.

The urinary exretion of chromium was studied for relationships to atherosclerotic diseases in two rural Finnish male populations, aged 55 to 74; one from eastern Finland, the other from the southwestern part of the country. A 10-year follow-up had shown a particularly high mortality from coronary heart disease in the eastern area where the concentrations of chromium in the drinking water were lower than in the western area. The 24-hr urinary excretions of chromium of the two populations were markedly low (east, mean +/- SEM, 3.60 +/- 0.15 microgram; west, 3.74 +/- 0.13 microgram), suggesting a suboptimal chromium intake in both populations. No consistent differences were found in urinary chromium excretions between groups with atherosclerotic diseases and reference groups. The role of low chromium intake in the pathogenesis of atherosclerosis deserves further study.

Aged↗
PubMed1997

[Changes in contents of chromium, zinc and copper in the blood, liver and kidney of diabetic rats].

Contents of chromium, zinc and copper in the blood (or serum), liver and kidney of diabetic rats induced by streptozotocin were determined for three weeks by graphite stove and flame atom absorption spectrophotometry to study the changes in trace elements in diabetics. Results showed liver chromium level increased significantly and kidney chromium level lowered significantly in diabetic rats, as compared with normal ones. Zinc and copper in liver and kidney and serum copper also increased to various extent during three-week observation period. No changes in chromium, zinc and copper levels in blood (or serum), liver and kidney, with the course of the disease, were observed. But, contents of trace elements in rats correlated with their blood sugar levels closely, and chromium, zinc and copper contents in the liver correlated with those in the kidney directly, and with chromium content in the kidney inversely. Therefore, improvement of blood sugar level in diabetic rats may, to a certain extent, improve the disturbance of trace elements in the body.

Animals↗
PubMed1993

Glucose-dependent uptake of chromium in human and rat insulin-sensitive tissues.

1. This study was designed to investigate the influence of insulin and glucose on the distribution of trivalent chromium in human plasma and blood cells and in human and rat insulin-sensitive and -insensitive tissues. 2. Evidence is provided that, in the rat in vitro, a clear difference exists in chromium binding between insulin-sensitive and -insensitive tissues in that chromium binding is significantly enhanced by glucose in insulin-sensitive tissues. 3. Glucose-dependent association of chromium with human adipose tissue was blocked by inhibitors of glucose transport. 4. Addition of insulin slightly increased the response to glucose in muscle and reduced the response to glucose in adipose tissue; such effects were less marked than those seen in response to glucose alone. 5. The results of this study in vitro support the hypothesis that, in vivo, chromium translocates from the blood compartment to insulin-sensitive tissues.

Adipose Tissue↗
PubMed1999

The biomimetic [Cr3O(O2CCH2CH3)6(H2O)3]+ decreases plasma cholesterol and triglycerides in rats: towards chromium-containing therapeutics.

The in vivo effects of administration of the synthetic, functional biomimetic [Cr3O(O2CCH2CH3)6(H2O)3]+ 1 and a naturally occurring, biologically active form of chromium, low-molecular-weight chromium-binding substance (LMWCr), to rats are described. Given that the complexes are proposed to function by interacting with insulin receptor, trapping it in its active conformation, in contrast to current chromium-containing nutrition supplements, which only serve as sources of absorbable chromium, changes in lipid and carbohydrate metabolism would be expected. After 12 weeks administration (20 micrograms/kg body mass), compound 1 results in 40% lower levels of blood plasma LDL cholesterol, 33% lower levels of total cholesterol, and significantly lower HDL cholesterol and triglyceride; these results are in stark contrast to those of administration of other forms of Cr(III) to rats, which have no effect on these parameters. LMWCr, in contrast to 1, has no effect as it probably is degraded in vivo or excreted. These results are interpreted in terms of the mechanism of chromium action in response to insulin and the activation of insulin receptor, and the potential for the rational design of chromium-containing therapeutics is discussed.

Animals↗
PubMed1993

Inhibition of heme oxygenase after oral vs intraperitoneal administration of chromium porphyrins.

The effects of chromium porphyrins on suckling rat heme oxygenase activity were compared following oral vs intraperitoneal dosing. Chromium protoporphyrin (CrPP), chromium mesoporphyrin (CrMP), or chromium deuteroporphyrin 2,4 bis glycol (CrBG) were administered at 40 mumol/kg to 2-week old suckling rats either orally or intraperitoneally. Six hours after intraperitoneal dosing, CrPP and CrMP had significantly reduced hepatic and splenic heme oxygenase activity by more than 55%. CrBG effectively reduced hepatic heme oxygenase activity by 42%. More importantly, only CrMP was an effective inhibitor of hepatic heme oxygenase activity 6 hr after oral administration. In the first reported comparison of chromium porphyrin efficacy in vivo, our data suggest that chromium porphyrins, and particularly CrMP, may be effective in chemopreventive strategies for the treatment of neonatal jaundice.

Administration, Oral↗
PubMed1993

Concentrations of zinc and chromium in aquatic macrophytes from the sudbury and muskoka regions of Ontario, Canada.

Root and shoot samples of Eriocaulon septangulare, Nuphar variegatum, Nymphaea odorata and Pontederia cordata were collected from 15 lakes in central Ontario during the summer of 1988 to investigate possible relationships between zinc and chromium levels in aquatic macrophytes and water and sediment variables. Although concentrations of zinc and chromium differed greatly among the four species, both metals were consistently higher in Eriocaulon. Generally, root and rhizome tissue contained higher zinc and chromium than shoot tissues of the same species and site. Zinc concentrations (dry weight) ranged from 6.3 microg g(-1) in Nuphar shoots to 87.7 microg g(-1) in whole Eriocaulon. Chromium ranged from 0.23 microg g(-1) in Pontederia shoots to 23.9 microg g(-1) in whole Eriocaulon. No significant trends were detected throughout the growing season in macrophyte or sediment concentrations of either metal. Results of multiple linear regression analyses of several water quality and environmental variables on Eriocaulon indicated that sediment zinc was the best predictor of plant zinc, and sediment chromium and calcium were the best predictors of plant chromium.

Journal Article↗
PubMed2003

Evaluation of antioxidant activity of leaf extract of Seabuckthorn (Hippophae rhamnoides L.) on chromium(VI) induced oxidative stress in albino rats.

The present study reports the antioxidant activity of Seabuckthorn (Hippophae rhamnoides), family Elaegnaceae, on chromium induced oxidative stress in male albino rats. Oxidative stress was induced in the rats by force-feeding of potassium dichromate equivalent to a dose of 30mg/kg body weight (BW) of chromium(VI) for 30 days. Administration of chromium decreased the body weight and increased organ to body weight ratio significantly. Chromium treatment significantly decreased reduced glutathione (GSH), and increased malondialdehyde (MDA) and creatine phosphokinase (CPK) levels; further it also enhanced glutamate oxaloacetate transferase (GOT) and glutamate pyruvate transferase (GPT) levels in the serum. Different doses of the alcoholic leaf extract of Seabuckthorn were evaluated for the protection against the chromium induced oxidative stress. The results show that the leaf extract at a concentration of 100 and 250mg/kg BW protected the animals from the chromium induced oxidative injury significantly.

Alanine Transaminase↗
PubMed2003

A weak, short metal-metal bond in a chromium(II) amidinate complex.

Treatment of chromium(II) chloride with 2 equiv of Li[tBuNC(CH3)NtBu], Li[iPrNC(CH3)NiPr], or Li[tBuNC(CH3)NEt] (prepared from the corresponding carbodiimides and methyllithium) afforded Cr[tBuNC(CH3)NtBu]2 (1, 50%), Cr[iPrNC(CH3)NiPr]2 (2, 54%), and [Cr(tBuNC(CH3)NEt)2]2 (3, 58%) as deep blue, purple, and amber or metallic green crystals, respectively. Cr[tBuNC(CH3)NtBu]2 and Cr[iPrNC(CH3)NiPr]2 possess monomeric structures in the solid state with tetrahedral and square planar geometries about the chromium centers, respectively. [Cr(tBuNC(CH3)NEt)2]2 exists as a dimer in the solid state, with two mu2-amidinate ligands, two eta2-amidinate ligands, and a chromium-chromium bond length of 1.9601(12) A. [Cr(tBuNC(CH3)NEt)2]2 is diamagnetic in the solid state, as determined by magnetic susceptibility measurement and CP/MAS 13C NMR spectroscopy. However, [Cr(tBuNC(CH3)NEt)2]2 dissociates into paramagnetic monomers in solution, as determined by observation of extremely broad peaks in the 1H NMR spectra in cyclohexane-d12 and benzene-d6, a solution magnetic moment measurement, and by solution molecular weight measurements in benzene. The combined results suggest that the chromium-chromium bond strength in [Cr(tBuNC(CH3)NEt)2]2 is weak and cannot exceed the difference in solvation energies between the dimer and two monomers, plus any increase in metal-nitrogen bond strengths in the monomers.

Journal Article↗
PubMed2001

Donor and acceptor properties of the chromium tricarbonyl substituent in benzylic and homobenzylic anions, cations, and radicals.

Both benzylic cations and anions are strongly stabilized by chromium tricarbonyl complexation, while benzylic radicals are largely unaffected. Density functional theory calculations were performed on primary, secondary, and tertiary benzylic species to explore the effect of substitution on the stabilizing ability of the chromium tricarbonyl moiety. Complexed 1-indanyl species were also examined to elucidate the effect of conformational restraint. It was found that the strong stabilization of benzylic anions and the slight destabilization of benzylic radicals by chromium tricarbonyl are insensitive to skeletal changes. Chromium-complexed benzylic cations, however, are highly sensitive to changes in the organic framework, with increased substitution or constriction of conformational mobility eroding the effect of the metal. 2-Indanyl species were also examined to study the effect of the chromium tricarbonyl fragment on homobenzylic species. It was found that the metal fragment stabilizes distant anions by field and inductive effects and cations by a direct interaction of the metal with the cationic carbon. Homobenzylic radicals, however, do not interact with the chromium tricarbonyl moiety and suffer a slight inductive destabilization.

Journal Article↗
PubMed2005

Use of chromium picolinate and biotin in the management of type 2 diabetes: an economic analysis.

This paper addresses the potential economic benefits of chromium picolinate plus biotin (Diachrome) use in people with Type 2 diabetes (T2DM). The economic model was developed to estimate the impact on health care systems' costs by improved HbA1C levels with chromium picolinate plus biotin (Diachrome). Lifetimes cost savings were estimated by adjusting a benchmark from the literature, using a price index to adjust for inflation. The cost of diabetes is highly dependent on the HbA1C level with higher initial levels and higher annual increments increasing the cost. Improvement in glycemic control has proven to be cost-effective in delaying the onset and progression of T2DM, reducing the risk for diabetes-associated complications and lowering utilization and cost of care. Chromium picolinate plus biotin (Diachrome) showed greater improvement of glycemic control in poorly controlled T2DM patients (HbA(1C) > or = 10%) compared to their better controlled counterparts (HbA(1C) < 10%). This improvement was additive to that achieved by oral hypoglycemic medications and correlates to calculated levels of cost savings. Average 3-year cost savings for chromium picolinate plus biotin (Diachrome) use could range from 1,636 dollars for a poorly controlled patient with diabetes without heart diseases or hypertension, to 5,435 dollars for a poorly controlled patient with diabetes, heart disease, and hypertension. Average 3-year cost savings was estimated to be between 3.9 billion dollars and 52.9 billion dollars for the 16.3 million existing patients with diabetes. Chromium picolinate plus biotin (Diachrome) use among the 1.17 million newly diagnosed patients with T2DM each year could deliver lifetime cost savings of 42 billion dollars, or 36,000 dollars per T2DM patient. Affordable, safe, and convenient, chromium picolinate plus biotin (Diachrome) could prove to be a cost-effective complement to existing pharmacological therapies for controlling T2DM.

Biotin↗
PubMed2000

Less than additive interaction between cigarette smoke and chromium(VI) in inducing clastogenic damage in rodents.

A combination of tobacco smoking with certain agents has been shown to exert synergistic carcinogenic effects. On the other hand, antagonism betweeen smoke and other pulmonary carcinogens has also been documented by both epidemiological and experimental data. In spite of a very large number of studies carried out for decades in workers exposed to hexavalent chromium, the influence of smoking habits on lung carcinogenesis induced by this metal has not been clarified. For this reason, we performed two studies evaluating clastogenic effects in rodents. In the first one, BDF(1) mice were exposed whole-body to mainstream cigarette smoke for 5 days and, on the last day, they received an i.p. injection of potassium dichromate. In the second study, Sprague-Dawley rats were exposed whole-body to environmental cigarette smoke for 18 consecutive days and for the same period of time they received daily intra-tracheal instillations of sodium dichromate. Individually, the two hexavalent chromium salts and cigarette smoke, either mainstream or environmental, enhanced the frequency of micronuclei in bone marrow polychromatic erythrocytes of both mice and rats. Moreover, individual exposure to either environmental cigarette smoke or sodium dichromate enhanced the frequency of micronuclei and multiple nuclei in pulmonary alveolar macrophages of rats. In both studies, combined exposure to cigarette smoke and hexavalent chromium produced less than additive clastogenic effects. These results are consistent with our previous data, showing that hexavalent chromium and either benzo[a]pyrene or cigarette smoke condensate behave antagonistically in in vitro mutagenicity test systems and that the chromium reducing capacity of human pulmonary alveolar macrophages and peripheral lung parenchyma is enhanced in smokers. Taken together, in the absence of any epidemiological evidence, these findings rule out any occurrence of synergism between cigarette smoke and hexavalent chromium, at least in certain stages of the carcinogenesis process.

Animals↗