Mutual Interaction of Airway Reflexes – Effects of Nasopharyngeal vs. Tracheo-bronchial Stimulations

Abstract

VEGA 1/0038/09 (prof. Jakus) and EC sources European Regional Development Fund (CECR) M E T H O D S Experimental animal: 22 anesthetized spontaneously breathing cats of both sexes (3.6±0.3 kg) Anaesthesia: sodium pentobarbital (35 mg / kg i.p. initially, then 1-3 mg / kg i.v. as needed) Monitoring: respiratory rate, blood pressure (BP), end tidal CO2 concentration, and body temperature (37 – 38 oC) Recording parameters: BP, esophageal pressure (EP), electromyograms of the diaphragm (DIA) and abdominal muscles (ABD) Stimulation: AspR mechanical probing of nasopharyngeal mucosa with thin nylon fiber loop or short air pressure pulses via pharyngostomy Cough continuos mechanical probing of tracheobronchial mucosa with thin nylon fiber loop for 10, 15, or 20 s Data analysis: Number of coughs and AspRs Peak inspiratory (I) and expiratory (E) EP Amplitudes of DIA and ABD electromyographic moving averages Durations of cough I and E phases, active E period and relative motor quiescence (inter-cough intervals) during cough, total cough cycle (Wang et al. 2009), latencies from the beginning of cough stimulation to the DIA activation and to the maximum of ABD activity in the first cough in the trial, cough related DIA and ABD activity, the overlapping of DIA and ABD cough activity Interactive cough – AspR trials were compared to the preceding and following control cough trials The results are given as: means ± S.E.M. Statistical processing was performed by GraphPad Instat software using appropriate tests: paired test and Wilcoxon matched pairs test P<0.05 was deemed as significant Mutual Interaction of Airway Reflexes – Effects of Nasopharyngeal vs. Tracheo-bronchial Stimulations