Adrenergic alpha-2 receptor antagonists cease augmented oxidation of plasma proteins and anxiety of rats caused by chronic noise exposure.

Background: Noise is one of the environmental factors, which is considered as a powerful stressor for the organism. Generally, the acoustic stress affects the behavior and physiological state of humans and animals.

Aims: The goal of this study is to investigate the relationship between chronic noise exposure and the effects of adrenergic alpha-2 receptor antagonists, beditin and mesedin, on the anxiety and oxidation of plasma proteins and fibrinogen in rats.

Methods: The experiments were carried out on non-linear albino male rats, divided into four groups (six animals in each): 1. Healthy controls 2. Exposed to noise of a level 91 dB(A), eight hours daily, during 7, 30 and 60 days; 3. Injected with 2 mg/kg of beditin (2-(2-amino-4-thiazolyl)-1,4-benzodioxane hydrochloride)); 4. Injected with 10 mg/kg mesedin (2-(2-methyl-amino-thiozolyl)-1,4-benzodioxane hydrochloride). For evaluating the cognitive impairment, the Any-maze test was applied. The level of carbonylation of proteins was assessed by reaction with 2,4-dinitrophenylhydrazine, spectrophotometrically.

Results: Chronic noise decreased locomotor activity and increased anxiety and oxidation of plasma protein and fibrinogen. Intensity of these changes were dependent on the duration of noise exposure.

Conclusion: The Alpha 2 adrenoblockers alleviate oxidative modification of plasma proteins and reduce the cognitive impairment caused by chronic exposure to noise.