Effect of capsaicin on the intraperitoneal axons of the rat trachea.
In vitro exposure of specimens of rat trachea to capsaicin at a concentration of 2 x 10(-4) g/ml was followed by a significant increase in the diameter and major changes in the vesicle content of intraepithelial axons with terminals containing a high proportion of large dense-cored vesicles and only scattered small vesicles, but had no effect on axons with terminals containing large numbers of closely-packed small vesicles. Twenty-four hours after in vivo treatment of rats with capsaicin at dose levels of 50 mg/kg, there was a highly significant reduction in the number of axons/unit length in the tracheal epithelium. This was attributed to similar patterns of degeneration of axons with terminals containing a high proportion of large dense-cored vesicles to those seen in the ureter and to the early elimination of the degenerating axons by phagocytosis by the epithelial cells.
D000818:Animals; D001369:Axons / Q000187:drug effects / Q000648:ultrastructure; D002211:Capsaicin / Q000494:pharmacology*; D004848:Epithelium / Q000648:ultrastructure; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D009411:Nerve Endings / Q000648:ultrastructure; D051381:Rats; D014132:Trachea / Q000033:anatomy & histology / Q000294:innervation*
D005231:Fatty Acids, Unsaturated; D002211:Capsaicin