title: An in vivo preparation for measurement of plasma protein and lysozyme output in the ferret tracheal lumen.
abstract: An in-vivo ferret tracheal preparation has been developed to study the appearance in the liquid-filled trachea of fluorescein-labelled plasma proteins (FLP) and of lysozyme from submucosal gland serous cells. In order to investigate the influence of nervous activity on the appearance of FLP and lysozyme in the tracheal lumen, the effects of intraluminal bradykinin (an inflammatory mediator and sensory nerve stimulant), intraluminal capsaicin (a stimulant of C-fibres) and electrical stimulation of the cut peripheral end of the right cervical vagus nerve have been measured. Vagal stimulation (10 V, 10 Hz, 1 ms, 90-120 s) increased the secretory rate of lysozyme. It had no effect on FLP rate of output. Intraluminal bradykinin (100 microM) produced a small but significant increase in FLP output but had no effect on lysozyme secretion. Intraluminal capsaicin (33 microM) had no effect on FLP output and had variable effects on lysozyme output. Tracheal pressure was increased by vagal stimulation but was unaffected by bradykinin and capsaicin. Thus, bradykinin increases plasma protein output, probably by an action on the epithelium, whilst vagal stimulation and capsaicin stimulate submucosal glands. This method could be used to determine the factors which alter the rate of movement of plasma proteins into the airway lumen and the secretion of submucosal glands in vivo.
authors.affiliation: Department of Physiology, St. George's Hospital Medical School, Tooting, London, UK.
authors.forename: U M
authors.initials: UM
authors.lastname: Wells
authors.forename: A
authors.initials: A
authors.lastname: Robson
authors.forename: S E
authors.initials: SE
authors.lastname: Webber
authors.forename: J G
authors.initials: JG
authors.lastname: Widdicombe
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D001920:Bradykinin / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D005289:Ferrets; D016650:Fluorescein-5-isothiocyanate; D008297:Male; D009113:Muramidase / Q000378:metabolism*; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology; D012636:Secretory Rate / Q000187:drug effects / Q000502:physiology; D013268:Stimulation, Chemical; D014132:Trachea / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D014630:Vagus Nerve / Q000502:physiology
chemical_list: D001798:Blood Proteins; D009113:Muramidase; D016650:Fluorescein-5-isothiocyanate; D002211:Capsaicin; D001920:Bradykinin