EN
The concentrations of Cu, Fe, Mn, Zn, Cd and Pb were determined by the AAS method in the brain (temporal and frontal cortex) of 40 dogs derived from the Wroclaw town. The animals were divided into 4 groups: group I — animals 3—6 months old, group В — 1—7 years old, group C — 8—14 years old, group D — 15—21 years old. It was found that the level of Cu and Fe increased with the age of dogs, i.e. in group A, В and C. Only in group D the progressive increase of these elements was not observed. A significant increase of Mn in the brain of animals was found aged over 7 years (group C) but in the oldest dogs (group D) the level of Mn did not rise. In respect to Zn there was stated a significant difference between its concentration in the tissues of dogs of В and C group. In the extremal groups of age (A and D) there were noted similar values of Zn. No correlation between Cd and Pb in relation to the age of animals was shown because of individual fluctuations in the quantities of these elements.