Rats were fed a casein based diet containing Cd biologically bound in ryegrass (Lolium multiflorum L. ssp. italicum) for eight weeks. The grass portion in the diet was 20% (w/w). Cd concentrations of the respective diets were (µg/g diet): 0.24 (control group Cd=0), 0.85 (group Cd=1) and 2.25 (group Cd=2). After six weeks on the diets, food intake and body weight were reduced by the low dietary Cd concentration (Cd=1), while in treatment group Cd=2 this occurred after 2 weeks. After an 8-week feeding period the concentrations of Cd, Cu, Zn, Fe and Ca in selected organs, tissues and in the excreta of rats beside whole body element contents were determined. While no elevated Cd levels due to the Cd intoxication were found in skin, lung, blood, testes, muscle and urine, Cd concentrations in liver, kidney and spleen increased in a dose-dependent manner. This was also true for whole body Cd and Cd in faeces, the latter being 27.6 fold higher in the high Cd load (Cd=2) as compared to the controls (Cd=0). Highest Cd concentrations were recorded in liver and kidney. Calculated as percentage of the whole body metal content liver Cd increased from 1.49% (Cd=0) to 7.41% (Cd=2) and kidney Cd from 0.65% to 4.87%. While no changes of the Ca levels in all organs and tissues investigated were observed, liver Zn increased and blood Cu decreased. Copper and Zn increased in faeces and decreased in urine. With the exception of skin and lung, a significant loss of Fe was observed in all organs and tissues, which was most evident in treatment group Cd=2. Depending on the Cd dose applied, reduced fecal and urinary Fe excretion occurred. Hematological parameters (hemoglobin, hematocrit, blood glucose) and serum enzyme activities (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, ?-glutamyl transferase) were not affected by Cd in a biologically bound form. Serum alanine amino transferase showed slightly lower activities in treatment groups Cd=1 and Cd=2. Analysis of the glucose concentration and the activity of alkaline phosphatase in urine did not reveal any changes due to the Cd intoxication. Accumulation and toxicological effects of Cd biologically bound in ryegrass are discussed in relation to inorganic forms of the metal administered to mammals.
Archives of Environmental Contamination and Toxicology 02/1987; 16(1):85-93. DOI:10.1007/BF01055363 · 1.96 Impact Factor