Age-related variations of lipid peroxidation in cadmium-treated rats

Under specific conditions, Cd can induce a prooxidant state in biological systems resulting in the peroxidation of the polyunsaturated fatty acids. We investigated in vivo this phenomenon in major target organs of Long Evans rats (12- and 36-week-old), 24 hours after being injected i.p. with a range of cadmium chloride doses (0.00, 0.05, 0.25, 1.0 or 2.5 mg Cd/kg). The measurements of the thiobarbituric acid reactive substances demonstrated that the lungs showed the highest Cd-induced LPO in the 12-week-old rats even if the liver and kidneys accumulated the greatest amounts of Cd. Cd-induced LPO as measured by TBARS assay in the 36-week-old groups was, in all organs, less pronounced even if the control levels were higher for these groups. The reasons for this age-dependent differences are not clear. Some components of the antioxidant defense system were differently modulated as a function of age. However, it is not certain whether these changes have a causative role in the induction of LPO following Cd exposure.