The evaluation of oxidative stress in the serum and tissue specimens of patients with chronic otitis media

Objectives

To underline the effect of oxidative stress in chronic otitis media with and without cholesteatoma and to compare the oxidative stress values in the serum and tissue specimens in these two forms.

Methods

The study included a total of 75 individuals, 35 cases with chronic otitis media (COM; 16 females and 19 males) and a healthy control group of 40 cases (20 females and 20 males). The COM patient group was comprised of 18 patients with cholesteatoma and 17 patients without cholesteatoma. All patients underwent mastoidectomy. Serum specimens were taken prior to surgery and diseased tissue specimens from the ear were obtained during surgery from all patients. Only serum specimens were taken from the healthy control cases. The malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GHPx) were measured in the serum and tissue samples of the patient group and in the serum specimens of the control group.

Results

The age ranged from 14 to 48 years in the patient group (mean age, 20.4±12.2 years) and from 19 to 40 years in the control group (mean age, 26.4±4.64 years). When the serum values of all COM patients were compared with those of the control group, in the patient group MDA, which reflects lipid peroxidation, was found to be significantly higher (P<0.01) whereas the antioxidant enzymes SOD, CAT, and GHPx were found to be significantly lower (P<0.01). When the serum and tissue MDA, SOD, CAT, and GHPx values in patients with and without cholesteatoma were compared, no significant difference was found these parameters (P>0.01).

Conclusion

Although oxidative stress plays a role in the pathogenesis of COM with or without cholesteatoma, it may not reflect the severity of the disease. In patients with COM, the evaluation of only serum oxidative stress values without tissue evaluation may be sufficient for assessing oxidative stress.

Effects of shock waves on oxidative stress in parotid gland of rat

This study was designed to investigate whether extracorporeal shock wave lithotripsy (ESWL) exposure to parotid gland produces an oxidative stress in parotid glands of rats. Twelve male Wistar-albino rats, 6 months of age with an average body weight of 250-300 g, were divided randomly into two groups, each consisting of six rats. The animals in the first group did not receive any treatment and served as control. The left parotid glands of animals in group 2 (ESWL treated) received a thousand 18 kV shock waves after anesthetizing the rats with 50 mg/kg of ketamine. The animals in both groups were killed 72 hours after the ESWL treatment, and the parotid glands were harvested for the determination of lipid peroxidation product malondialdehyde (MDA), antioxidant glutathione (GSH) levels and the activities of antioxidant enzymes such as superoxide dismutase (SOD), GSH-Px and catalase (CAT). It was found that MDA level increased in parotid glands of rats after the ESWL treatment. The SOD, GSH-Px and CAT enzyme activities, and the level of antioxidant GSH decreased in parotid gland of rats after the ESWL treatment. It was concluded that short-term ESWL treatment caused an increase in the free radical production and a decrease in the antioxidant enzyme activity in parotid glands of ESWL-treated rats.