Oxidative injury of atmospheric particulate matter on myocardium tissue of rats

Objective To explore oxidative injury of atmospheric particulate matter exposure on myocardium tissue of rats.

Methods A total of 48 specific pathogen-free male Sprague-Dawley rats were randomly divided into control group (3 months, n=12; 6 months, n=12) and exposure group (3 months, n=12; 6 months, n=12). Rats in the control group were raised in individually ventilated cages (IVCs) in which atmospheric PM was filtered, while rats in the exposure group were raised in IVCs in which atmospheric PM was not filtered. Hematoxylin-eosin staining was used to observe the pathological changes of rat's myocardial tissue after 6 months. After 3 and 6 months, enzyme-linked immunosorbent assay was used to measure the levels of glutathione peroxidase(GSH-Px), superoxide dismutase (SOD), myeloperoxidase (MPO) and malondialdehyde (MDA) in myocardial tissue of the rats, and Western blot was used to measure the protein expression levels of interleukin-1β (IL-1β), interleukin-8 (IL-8), and vascular cell adhesion molecule-1 (VCAM-1) in the rat's myocardial tissue.

Results The cells of myocardial tissue in the 6-month exposure group showed a disordered arrangement and massive inflammatory cell infiltration under the light microscope. Compared with the control group, the 3-month exposure group had a significantly decreased activity of GSH-Px and significantly increased MDA level and IL-8 and VCAM-1 protein expression (all P < 0.05); the 6-month exposure group had significantly increased MPO activity, MDA level, and IL-8 and IL-1β protein expression (P < 0.05).

Conclusion Atmospheric PM exposure can lead to oxidative stress injury in myocardial tissue of the rats and an increase in the expression of inflammatory factors.