Protective effects of glutathione and lipoic acid against cadmium-induced oxidative stress in rat's kidney.

Cadmium is a widespread, toxic industrial pollutant. The proximal tubule of the mammalian kidney is a major target of Cd-induced toxicity. We analyzed the effects of cadmium exposure on the model system of experimental animals, the thiobarbituric acid (TBA)-reactive substance (TBARS) level, and the activity of xanthine oxidase (XO) and catalase in kidney of rats, with and without glutathione and lipoic acid (LA). The experimental animals were classified into six groups, regarding cadmium, glutathione, and LA intake. The concentration of TBARSs in the homogenate was determined by spectrophotometric method according to Nabavi et al. The specific activity of XO was determined spectrophotometrically by the method of Aygul et al. Catalase activity in tissues was determined by spectrophotometric method according to Nabavi et al. The increased level of TBARS and the increased activity of XO in kidney tissue in cadmium poisoning are statistically significant compared to control (p < 0.001). Glutathione and LA applied along with cadmium lowered TBARS concentration and reduced XO activity (p < 0.001). Catalase activity in the kidney tissue was increased in the group, which was administered cadmium (p < 0.001). In conclusion, glutathione and LA, as physiological antioxidants applied with cadmium, have reduced the level of lipid peroxide and the activity of XO, and can be used as protectors in conditions of cadmium poisoning.

Copper release from dental prosthetic crowns, dental materials, and human teeth into acetic acid.

This article examines the dilution of the ion of copper from human teeth and dental prosthetic crowns in 4% CH(3)COOH during a period of 24 hr at room temperature. The content of the diluted copper in an acetate extract, as well as the overall content of this metal in the samples, was determined by means of a potentiometric stripping analysis. The comparative measurements were carried out using the furnace atomic absorption spectrophotometry technique, which is recommended by the International Standards (ISO 6872:2008; ISO 24234:2004) as a method for quality control of dental-prosthetic material (dental ceramic, metal restorative materials, dental amalgams) in the process of checking for heavy metals. During a 24-hr period in 4% CH(3)COOH at a temperature of 25 degrees C, approximately 72% of the overall copper was released from the tooth. The percentage of the released copper from baby teeth is higher, ranging from 88 to 92%, which is probably a consequence of the bone tissue being in development, its infirmity, and inadequate stability. On these conditions, approximately 72% of the overall copper was released from the dental-ceramic prosthetic crowns.

Potentiometric stripping analysis of zinc and copper in human teeth and dental materials.

Potentiometric stripping analysis (PSA) with oxygen as the oxidant has been used to determine soluble zinc and copper levels in exfoliated human teeth (all of which required extraction for orthodontic reasons) and commercial dental materials. The soluble zinc and copper contents of teeth were slightly below the zinc and copper contents in whole teeth reported by other researchers, except in the case of tooth with removed amalgam filling. Soluble zinc and copper concentrations of the dental materials and metal ceramic crowns were 0.50-6.30, and of 2.00-4.30 microg/g, respectively. The results of this work suggest that PSA may be a good method for zinc and copper leaching studies during the investigation of dental prosthetic materials' biocompatibility. Corrosive action of acidic media as evidenced by SEM micrographs caused the leaching of metal ions from teeth.