Exposure to noise stress is associated with increased respiratory system morbidity; however the underlying mechanisms are unclear. Thus there is a need for more study about this harmful effect. Sulpiride had been shown to have a protective role against noise stress on other systems but this role did not studied well on respiratory system.
Aim of the work: To investigate using histological, histochemical and morphometric methods the possible harmful effects of noise on adult female albino rats' lung, heart and the possible protective role of combined sulpiride treatment.
Material and Methods: The present study was carried out on 24 adult female albino rats which were randomly divided into Group 1(C, untreated negative control), Group 2 (N, noise exposed or positive control) where rats were exposed to noise “>90 decibel/3h/day" for 1 month, Group 3(D, sulpiride treated) where rats were exposed to sulpiride “0.028 mg/B.W./day" and Group 4 (N+D, noise+ sulpiride exposed). Paraffin sections were prepared for histological, histochemical and morphometric study. Also statistical analysis was done.
Results: Rats exposed to noise only or sulpiride only showed highly significant damaging changes on lung such as thickening in the interalveolar septa and obliteration of the alveoli, inflammatory cells infiltration within the pulmonary interstitium, peribronchiolar infiltration and fibrosis, thickening of the pulmonary blood vessels walls, interstitial collagen fibres deposition and apoptotic cellular changes. On the level of heart, highly significant decrease in the diameters of the myocardial muscle fibres with focal areas of necrosis and apoptotic changes was detected. Also, increased collagen fibres deposition was marked in sulpiride group. When noise and sulpiride treatment was combined, the damaging effects were maximized on the lung and to a lesser extent on the heart.
Conclusion: These results provide evidence that noise stress cause obvious lung and heart tissue damages. No protective role for sulpiride was proofed. This is as using sulpiride alone or in combination with noise showed marked damaging effects on the lung and heart tissues.