title: Effects of expectorants on the canine tracheal ciliated cells.
abstract: Many expectorants are clinically effective as they reduce viscosity and facilitate expectoration. There are, however, few reports on effects of expectorants on tracheal ciliated cells. We investigated the effects of N-acetylcysteine, ethylcysteine and bromhexine on the ciliary activities of the canine trachea. Ciliary movement was estimated using a phototransistor, and intracellular electrical activity was measured with a microelectrode method, in vitro. N-Acetylcysteine, ethylcysteine and bromhexine in low concentrations under a low perfusion rate (0.1 ml/min) produced an increase in the amplitude and frequency of ciliary beating, while N-acetylcysteine and ethylcysteine caused a cilio-depression in high concentration. N-Acetylcysteine, ethylcysteine and bromhexine, under a low perfusion rate, did not affect the intracellular electrical activity. On the other hand, these three drugs under a high perfusion rate (1 ml/min) produced no change in the ciliary movement and the intracellular electrical activity in concentrations of 10(-8)-10(-4) M. These results suggest that the increase in ciliary activity produced by the mucolytic drugs is not due to a direct effect on the ciliated cells, but rather to a mucolytic effect on the mucus around the cilia.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D001964:Bromhexine / Q000494:pharmacology; D002923:Cilia / Q000187:drug effects*; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D004285:Dogs; D005100:Expectorants / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009093:Mucus / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects*
chemical_list: D005100:Expectorants; C026826:S-ethylcysteine; D003545:Cysteine; D000109:Acetylcholine; D001964:Bromhexine; D011188:Potassium; D000111:Acetylcysteine