Markers of lipid peroxidation and α-tocopherol levels in the blood and neoplastic tissue of dogs with malignant mammary gland tumors

• Published in: Veterinary clinical pathology Vol. 42; no. 3; pp. 323 - 328
• Main Authors: Karayannopoulou, Maria, Fytianou, Anna, Assaloumidis, Nikolaos, Psalla, Dimitra, Constantinidis, Theodoros C., Kaldrymidou, Eleni, Koutinas, Alexander F.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-09-2013
• Subjects: alpha-Tocopherol - blood; alpha-Tocopherol - metabolism; Animals; Biomarkers - blood; Biomarkers - metabolism; Carcinoma - metabolism; Carcinoma - pathology; Carcinoma - veterinary; Dog Diseases - metabolism; Dog Diseases - pathology; Dogs; Female; Inflammatory cancer; Lipid Peroxidation; Mammary Glands, Animal - metabolism; Mammary Neoplasms, Animal - metabolism; Mammary Neoplasms, Animal - pathology; oxidative burst; Oxidative Stress; Thiobarbituric Acid Reactive Substances - metabolism; thiobarbituric acid-reactive substances; Inflammatory cancer; oxidative burst; thiobarbituric acid-reactive substances
• ISSN: 0275-6382; 1939-165X
• DOI: 10.1111/vcp.12064

Background
Excess reactive oxygen species due to oxidative stress and the ensuing lipid peroxidation are believed to be involved in mammary gland tumor (MGT) pathogenesis.
Objective
The purpose of this study was to evaluate the extent of lipid peroxidation as evidenced by thiobarbituric acid‐reactive substances (TBARS) formation, and the concentration of α‐tocopherol as an inhibitor of lipid peroxidation, in blood and neoplastic tissue of dogs with malignant MGT. The correlation between inflammatory cell infiltration score and TBARS or α‐tocopherol in MGT was also evaluated.
Methods
Sixteen intact female dogs with malignant MGT and 12 clinically healthy and age/weight‐matched controls were included in the study. In all dogs, serum TBARS, α‐tocopherol, total cholesterol, and triglycerides were measured. Tissue TBARS and α‐tocopherol levels were determined in 1 cm3 sized tissue samples collected from MGT and adjacent, ipsilateral, normal mammary gland tissue from the 16 affected dogs. The degree of inflammatory cell tumor infiltration was evaluated histologically.
Results
There were no statistically significant differences in serum levels of TBARS, α‐tocopherol, total cholesterol, and triglycerides between dogs with and without malignant MGT. TBARS were significantly higher, whereas α‐tocopherol was lower in neoplastic tissue when compared with normal mammary gland tissue. There was no correlation between TBARS or α‐tocopherol concentration and the inflammatory cell infiltration score in neoplastic tissue.
Conclusion
The increased level of TBARS suggests oxidative stress induction in canine malignant MGT. The origin of this phenomenon is not clear, as a potential oxidative burst could not be attributed to inflammatory cells infiltrating the tumors.