Evaluation of level of DNA damage in blood leukocytes of non-diabetic and diabetic rat exposed to cigarette smoke

• Published in: Mutation research. Genetic toxicology and environmental mutagenesis 2007-04, Vol.628 (2), p.117-122
• Main Authors: Lima, Paula Helena Ortiz, Sinzato, Yuri Karen, de Souza, Maricelma da Silva Soares, Braz, Mariana Gobbo, Rudge, Marilza Vieira Cunha, Damasceno, Débora Cristina
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cigarette smoke; Comet assay; Diabetes; Diabetes. Impaired glucose tolerance; DNA damage; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Medical sciences; Streptozotocin (STZ); Toxicology
• ISSN: 1383-5718; 1879-3592
• DOI: 10.1016/j.mrgentox.2006.12.004

The objective of the present study was to use the comet assay to evaluate the steady-state level of DNA damage in peripheral blood leukocytes from diabetic and non-diabetic female Wistar rats exposed to air or to cigarette smoke. A total of 20 rats were distributed into four experimental groups ( n = 5 rats/group): non-diabetic (control) and diabetic exposed to filtered air; non-diabetic and diabetic exposed to cigarette smoke. A pancreatic beta (β)-cytotoxic agent, streptozotocin (40 mg/kg b.w.) was used to induce experimental diabetes in rats. Rats placed into whole-body exposure chambers were exposed for 30 min to filtered air (control) or to tobacco smoke generated from 10 cigarettes, twice a day, for 2 months. At the end of the 2-month exposure period, each rat was anesthetized and humanely killed to obtain blood samples for genotoxicity analysis using the alkaline comet assay. Blood leukocytes sampled from diabetic rats presented higher DNA damage values (tail moment = 0.57 ± 0.05; tail length = 19.92 ± 0.41, p < 0.05) compared to control rats (tail moment = 0.34 ± 0.02; tail length = 17.42 ± 0.33). Non-diabetic (tail moment = 0.43 ± 0.04, p > 0.05) and diabetic rats (tail moment = 0.41 ± 0.03, p > 0.05) exposed to cigarette smoke presented non-significant increases in DNA damage levels compared to control group. In conclusion, our data show that the exposure of diabetic rats to cigarette smoke produced no additional genotoxicity in peripheral blood cells of female Wistar rats.