Oxidative-antioxidative status of blood plasma in bitches with mammary gland tumours

The aim of the study was the estimation of oxidative/antioxidative status of bitches with mammary gland tumours by the determination of lipid peroxidation intensity, concentration of glutathione and β-carotene as well as total antioxidant capacity (TAC) in blood plasma. The experiment was carried out on 18 bitches with spontaneously occurring mammary gland tumours (12 with malignant tumours and 6 with benign tumours) and 6 clinically healthy controls. The intensity of lipid peroxidation did not differ significantly among the examined groups of animals. The concentration of glutathione was higher in both neoplasm groups than in healthy bitches, but the differences were not significant. The concentration of β-carotene in plasma was similar in cases of malignant and benign tumours, but was significantly lower (P<0.05) than in healthy controls. TAC of plasma was lower in bitches with tumours than in healthy animals. Significant difference was noticed between malignant tumours and controls (P<0.01). In conclusion, the alterations in antioxidative status occur in bitches with mammary gland tumours, suggests the presence of general antioxidative stress. A necessity of more frequent sample collection for the detection of dynamic changes in peroxidation process revealing the intensity of oxidative stress in bitches suffering from mammary gland tumours should be considered.