Effects of 0. 5 ppm ozone on glycoprotein secretion, ion and water fluxes in sheep trachea
We studied the effects of ozone (O3) exposure on airway mucus secretion. Sheep were exposed in vivo to 0.5 ppm O3, 4 h/day for 2 days (acute, n = 6), 6 wks (chronic, n = 6) or 6 wks + 1 wk recovery (chronic + recovery, n = 6). Secretion of glycoproteins (radiolabeled with 35SO4 and (3H)threonine), and transepithelial fluxes of Cl-, Na+ and water were subsequently measured in tracheal tissues in vitro, and were compared with values from control, unexposed sheep (n = 8). Acute O3 exposure increased basal secretion of sulfated glycoproteins (P less than 0.05), but had no effect on ion fluxes. Chronic exposure reduced basal glycoprotein secretion, but increased net Cl- secretion. Under open-circuit conditions, chronic exposure also induced net water secretion (P less than 0.05). With 7 days recovery, basal glycoprotein secretion (predominantly sulfated) was greatly increased above control, while the increased net secretion of Cl- and of water persisted (P less than 0.05). Histology of the airways indicated that acute exposure induced moderate hypertrophy of submucosal glands in the lower trachea (P less than 0.05), while chronic exposure (with and without recovery) induced a large hypertrophy of submucosal glands in both upper and lower trachea (P less than 0.05). Without recovery, however, the gland cells were devoid of secretory material, whereas with recovery they were full of secretory material. This suggests that the decreased glycoprotein secretion with chronic exposure alone resulted from incomplete replenishment of intracellular stores after 6 wks of stimulation. We conclude that both short- and long-term O3 exposure causes airway-mucus hypersecretion.
- Research Organization:
- Mount Sinai Medical Center, Miami Beach, FL
- OSTI ID:
- 5674277
- Journal Information:
- J. Appl. Physiol.; (United States), Vol. 3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of ozone on the cholinergic secretory responsiveness of ferret tracheal glands
Effect of ozone on the postnatal development of lamb mucociliary apparatus
Related Subjects
GLUCOPROTEINS
SECRETION
MUCOUS MEMBRANES
OZONE
BIOLOGICAL EFFECTS
CHLORIDES
CHRONIC EXPOSURE
ELECTROPHYSIOLOGY
SHEEP
SODIUM
SULFUR 35
TRACER TECHNIQUES
TRACHEA
TRITIUM COMPOUNDS
ALKALI METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELEMENTS
EVEN-ODD NUCLEI
HALIDES
HALOGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MEMBRANES
METALS
NUCLEI
ORGANIC COMPOUNDS
PHYSIOLOGY
PROTEINS
RADIOISOTOPES
RESPIRATORY SYSTEM
RUMINANTS
SACCHARIDES
SULFUR ISOTOPES
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)