Tissue accumulation and urinary excretion of chromium in rats fed diets containing graded levels of chromium chloride or chromium picolinate

Abstract

-To attempt a risk assessment of the excess intake of trivalent chromium (Cr), tissue Cr accumulation and urinary Cr excretion were examined in weanling rats fed experimental diets containing graded levels of Cr chloride (CrCl 3 ) or Cr picolinate (CrPic). Thirty-six male weanling 4-weeks-old Wistar rats were divided into six groups and fed a casein-based semi-purified diet (Cr content: < 0.02 μg/g) supplemented with 1, 10, or 100 μg Cr/g as CrCl 3 or CrPic for 28 days. Among the experimental groups, no significant difference was observed in body weight; however, supplementation of 100 μg Cr/g to the diets caused a significant low liver weight irrespective of the chemical species of Cr. Activities of serum aspartate aminotransferase and alanine aminotransferase were significantly elevated in rats given CrPic at 100 μg Cr/g. In the liver, kidney and femur, Cr accumulation increased with elevation of the dietary Cr level. No influence of the difference in the chemical species of supplemented Cr was observed in the liver and kidney, but CrCl 3 caused significantly higher Cr accumulation than CrPic in the femur of rats given 100 μg Cr/g. Daily urinary Cr excretion elevated with the increase of the dietary Cr level. Rats given CrPic showed significantly higher daily urinary Cr excretion than those given CrCl 3 , particularly at a dietary Cr level of 100 μg/g. The rate of urinary Cr excretion in rats given CrPic was constant, irrespective of the dietary Cr level, but that of rats given CrCl 3 fell with the increase of the dietary Cr level. These results indicate that the lowest adverse effect level of dietary Cr is less than 100 μg/g, irrespective of the chemical species of Cr.

The Effects of Supplementary Cr3 (Chromium(III) Propionate Complex) on the Mineral Status in Healthy Female Rats

“…This turn leads to the hypothesis that chromium ion supplementation have been beneficial only in disorders of glucose and lipid metabolism [ 35 ]. Most of the available literature exploring the effects of chromium supplementation in rats have been short-term studies [ 4 , 25 , 27 – 29 , 36 , 37 ]. Few have looked at the effect of long-term chromium supplementation [ 17 , 31 , 38 , 39 ].…”

“…Lindemann et al [ 45 ] demonstrated differences between Cr sources in Cr concentrations in various tissues. In a study conducted by Yoshida et al [ 37 ], the different effects of Cr on Cr concentration in the liver, kidney and femur were the result of the dietary Cr level (1, 10,100 μg· g −1 diet) than chemical form (CrPic vs. CrCl 3 ). However, the greatest Cr concentration was found in kidneys, which was also confirmed in our study.…”

Disturbance of antioxidant protection and natural resistance factors in rats with different availabilities of trivalent chromium

“…For this reason, Yoshida et al (26) indicated the lowest adverse effect level of water Cr(III) supplementation to be 100 µg/g Cr 3+ . However, in the discussed experiment, changes in the antioxidant system of rats were observed Table 2.…”

Estrogenic effect of chromium – an important metalloestrogen in the modulation of endocrine pathways

“…Stwierdzono także tendencję do gromadzenia się jonów chromu triwalentnego w organizmie, co pociąga za sobą znaczne ryzyko wystąpienia odległych efektów cytotoksycznych, mutagennych i genotoksycznych. Wykazano, że CrPic działa mutagennie w komórkach bakteryjnych i ssaczych in vitro [42,43,44]. W oparciu o analizę dostępnych danych, amerykańska Agencja Żywności i Leków (ang.…”