Publications by authors named "U M Wells"

The tracheae of ferrets and rabbits were mounted in vitro in organ baths. While the tracheae were liquid filled, the permeability coefficient ( P) was determined, and then while the tracheae were air filled, the percent clearance for 99mTc-labeled diethylenetriaminepentaacetic acid (DTPA) was determined. The thickness of airway surface liquid (ASL) was estimated by three methods.

View Article and Find Full Text PDF

Exogenous hydrogen peroxide (H2O2) causes airway epithelial damage in vitro. We have studied the effects of luminal H2O2 in the sheep trachea in vivo on tracheal permeability to low-molecular-weight hydrophilic (technetium-99m-labeled diethylenetriamine pentaacetic acid; 99mTc-DTPA) and lipophilic ([14C]antipyrine; [14C]AP) tracers and on the tracheal vascular response to luminal capsaicin, which stimulates afferent nerve endings. A tracheal artery was perfused, and tracheal venous blood was collected.

View Article and Find Full Text PDF

Inhaled sodium metabisulphite (MBS) causes bronchoconstriction, cough and microvascular leakage. We have studied its effects on tracheal blood flow, potential difference (PD) and the permeability from tracheal lumen to venous blood of a low molecular weight hydrophilic tracer, 99mtechnetium-labelled diethylenetriamine penta-acetic acid (99mTc-DTPA) in anaesthetized sheep. Flow was measured in tracheal artery and blood from a cannulated tracheal vein collected for 5 min periods.

View Article and Find Full Text PDF

Epithelial damage greatly increases the flux of a low molecular weight tracer 99mtechnetium-diethylenetriamine penta-acetic acid (99mTc-DTPA) from tracheal lumen to venous-blood in anaesthetized sheep. We have now investigated whether epithelial damage induced by the detergent, Triton X-100, alters the effects of luminal histamine on blood flow and 99mTc-DTPA flux. The cervical trachea was filled with Krebs-Henseleit solution containing 99mTc-DTPA.

View Article and Find Full Text PDF

Tracheal osmolaity affects blood flow and the flux of a tracer, technetium-99m-labeled diethylenetriamine pentaacetic acid (99mTc-DTPA), from tracheal lumen to venous blood in anesthetized sheep. Hyperosmolar liquids increase blood flow and slightly decrease 99mTc-DTPA flux, whereas hyposmolar liquids have no effect on blood flow and greatly increase 99mTc-DTPA flux. We have now investigated whether epithelial damage induced by exposure of the tracheal lumen to a detergent (0.

View Article and Find Full Text PDF