In Vivo Effects of Chromium

Abstract

The production of reactive oxygen species on addition of hexavalent chromium (potassium dichromate, K2Cr2O7) to lung cells in culture was studied using flow cytometer analysis. A Coulter Epics Profile II flow cytometer was used to detect the formation of reactive oxygen species after K2Cr2O7 was added to A549 cells grown to confluence. The cells were loaded with the dye, 2',7'-dichlorofluorescein diacetate, after which cellular esterases removed the acetate groups and the dye was trapped intracellularly. Reactive oxygen species oxidized the dye, with resultant fluorescence. Increased doses of Cr(VI) caused increasing fluorescence (10-fold higher than background at 200 microM). Addition of Cr(III) compounds, as the picolinate or chloride, caused no increased fluorescence. Electron paramagnetic resonance (EPR) spectroscopic studies indicated that three (as yet unidentified) spectral "signals" of the free radical type were formed on addition of 20, 50, 100, and 200 microM Cr(VI) to the A549 cells in suspension. Two other EPR "signals" with the characteristics of Cr(V) entities were seen at field values lower than the standard free radical value. Liver microsomes from male Sprague-Dawley rats treated intraperitoneally with K2Cr2O7 (130 mumole/kg every 48 hr for six treatments) had decreased activity of cytochromes P4503A1 and/or 3A2, and 2C11. Hepatic microsomes from treated female Sprague-Dawley rats, in contrast, had increased activities of these isozymes. Lung microsomes from male Sprague-Dawley rats had increased activity of P4502C11.

Combination Effect of Light and Toxicity in Algal Tests

“…This raises the question, What is known about the mechanism of action of potassium dichromate? Chromate crosses biological membranes and has a strong oxidative power that produces a high concentration of reactive species of O 2 inside cells (Bassi et al, 1990; Taylor et al, 1979; Witmer et al, 1994), which can impair the photopigments. Baszynski (1981) reported that chromate strongly decreases the pigment content, inhibits photosystem II activity, and disorganizes the fine structure of chloroplasts of Lemna minor Whether the observed effect of higher maximum chromium toxicity at high light conditions is the result of a specific interaction, for example, caused by an increase of the redox potential of potassium dichromate enhancing its oxidative power, is not clear and can only be speculated.…”

Curcumin Pretreatment Prevents Potassium Dichromate-Induced Hepatotoxicity, Oxidative Stress, Decreased Respiratory Complex I Activity, and Membrane Permeability Transition Pore Opening

“…Cr(VI) salts such as potassium dichromate (K 2 Cr 2 O 7 ) or chromic acid are widely used in leather, chrome-plating, and dye-producing industries [20, 21]. Occupational and environmental exposure to Cr(VI)-containing compounds is known to be toxic, mutagenic, and carcinogenic to human beings and diverse animals [22–24], leading to serious damage to the kidneys [25, 26], liver [27, 28], lungs [29, 30], skin [31], and other vital organs [32–34]. …”

Effect of Garlic (Allium sativum) on Heavy Metal (Nickel II and ChromiumVI) Induced Alteration of Serum Lipid Profile in Male Albino Rats

“…The high TG level along with decreased absorption of fatty acids by adipose tissue is associated with a low level of HDL-C, insulin resistance and increased risk of atherosclerosis [27]. In our study, high cholesterol level in chromium intoxication may also be due to decreased activity of cytochrome P450 enzymes [28]. The rise in serum lipid profile may also be attributed to increased lipolysis, mediated by increased norepinephrine release which act through interference with the intracellular functions of Ca +2 in the cytoplasm [29].…”