Briefly, 10% (weight/volume) homogenates of kidney and liver obtained from 0.1 mol/l phosphate buffer were centrifuged at 4 C and 3500 rpm for 10 min. 0.2 ml supernatant was mixed with 0.67% 2-thiobarbituric acid (TBA) and 20% trichloroacetic acid solution, and then heated in a boiling water bath for 30 min. The pink-colored chromogen formed by the reaction of TBA with MDA was measured at 532 nm. Results were expressed as MDA nmol/mg protein. Contents of protein in the supernatant were measured by the Lowry’s method .