Response of Smooth Bronchial Musculature in Bronchoconstrictor Substances in Newborn with Lung Atelectasis at the Respiratory Distress Syndrome (RDS)

OBJECTIVE: Role of the atelectasis (hypoxia) in the respiratory system of the live and exited newborn (250 up to 3000 g. of body weight), which has died due to different causes was studied in this work. METHODS: Response of tracheal rings to dopamine, serotonine and ethanol in the different molar concentrations (dopamine: 0,05 mg/ml, 0,5 mg/ml, 5 mg/ml; serotonine (5-HT): 10(-4), 10(-3), 10(-2), 10(-1) mol/dm(3); ethanol: 0,2 ml, 0,5 ml, 1,0 ml; 96%) was followed up. Study of the smooth tracheal musculature tone (STM) was elaborated in 16 tracheal preparations taken following the newborn death due to different causes. RESULTS: Based on functional researches of tracheal isolated preparations, it was ascertained as follows: atelectasis (cases born with lung hypoxia) has changed the response of STM to dopamine, serotonine and ethanol in a significant manner (p<0,01) in comparison to cases of controlling group, which has died due to lung inflammatory processes (e.g. pneumonia, bronchopneumonia, cerebral hemorrhage), which have also caused significant response (p<0,05). CONCLUSION: Results suggest that exited cases from lung atelectasis and cases of controlling group reacts to above mentioned substances by causing significant constrictor action of tracheobronchial system.