Patricia M. Joseph

The effects of chronic sidestream cigarette smoke exposure on eicosanoid production by tracheal epithelium

Environmental exposure to sidestream cigarette smoke (SSCS) has been associated with an increased incidence of pulmonary infection and bronchospasm. Chronic exposure to SSCS could modify the release of bronchoreactive eicosanoids by tracheal epithelium, the site of initial contact by lung with inhaled toxins. To assess this possibility, New Zealand white rabbits were placed in an environmental chamber flushed with 3 L of SSCS, 15 min/day for 20 days. Eighteen hours after the last exposure the animals were sacrificed and the tracheas were explanted. At 7 days, the epithelial cell outgrowths were exposed to media containing endotoxin (10 micrograms/mL) or acrolein (50 microM), an aldehyde commonly found in smoke, or to control media. After a 2-h exposure, media were assayed for eicosanoids by radioimmunoassay. PGE2 was produced in epithelium from normal animals (5.7 +/- 1.3 ng/10(6) cells), and was not significantly different in SSCS-exposed epithelium. When incubated in medium containing acrolein, PGE2 production increased significantly in SSCS-exposed epithelium (14.9 +/- 2.5, p < .05) but not in control groups. Endotoxin also increased PGE2 production in SSCS-exposed cells (12.6 +/- 3.3 ng/10(6), p < .05). Baseline production of 6-keto PGF1 alpha was 10.8 +/- 3.2 ng/10(6) cells in non-SSCS controls and did not change significantly in these cells with the addition of endotoxin or acrolein. In acrolein plus SSCS-exposed cells, 6-keto PGF1 alpha increased, in a dose-dependent manner, to 88.1 +/- 26.1 ng/10(6) (p < .05 compared to all normals, SSCS-exposed controls, and SSCS plus LPS). TxB2 release in control, non-SSCS-exposed cells was 13.3 +/- 2.8 ng/10(6) cells and was significantly increased (P < .05) only in the SSCS plus acrolein group (60.7 +/- 16.2 ng/10(6) cells). The results indicate that even brief, recurrent exposure to SSCS can change the production of cyclooxygenase products, particularly PGE2, 6- keto PGF1 alpha, and TxB2. This may reflect an altered ability of SSCS-exposed tracheal epithelium to respond to environmental (e.g., acrolein) or bacterial (e.g., endotoxin) insults.

Chronic Sidestream Cigarette Smoke Exposure Causes Lung Injury in Rabbits

The effects of sidestream cigarette smoke (SSCS) (a 15-min exposure per day for 20 days) were determined on markers of lung injury in New Zealand white rabbits (n = 9) and a control group (n = 6). The SSCS consisted of air and smoke which were aspirated by syringe from a funnel inverted over a lit ciga rette. The rabbits were placed in an environmental chamber into which 3 liters of SSCS were injected over a 15-min period each day. Chronic SSCS caused an increase (p < 0.05) in pulmonary epithelial clearance (k) of technetium labeled diethylenetriamine pentaacetate (99mTcDTPA); k = 0.83 (±0.07) for the SSCS-exposed group and 0.66 (± 0.02) for the control group. This increase in lung permeability was accompanied by an increase in bronchoalveolar lavage (BAL) white cell count; SSCS = 83,353 ( ± 11,954) cells/mm3 BAL fluid versus control = 16,450 (± 6,683) cells/mm3 BAL fluid and an increase in BAL leukotriene E4; SSCS = 742 (± 285) pg/ml BAL fluid compared with 76 (± 2) pg/ml BAL fluid for controls. Cultured SSCS alveolar macrophages (AMs) produced more superoxide (O2); 2.4 (± 0.8) nmol O2/106 AMs versus 0.4 (± 0.2) nmol O2/106 AMs for controls after incubation for 18 h with 10 μg/ml lipopolysaccharide. Electron microscopy demonstrated that the airway mu cosa of SSCS rabbits was infiltrated by eosinophils, and light microscopy showed focal clusters of neutrophils in perivascular and capillary spaces. It is concluded that SSCS exposure can induce lung injury.

S5.8 Chemical composition of two commercial heparins with differing antiproliferative effect on smooth muscle cells

aggregation of cells from the marine sponge Microciona prolifera. Homophilic binding of an extracellular adhesion proteoglycan mediates aggregation in the presence of Ca 2÷. Aggregation-inhibiting monoclonal antibodies produced against the purified proteoglycan recognize carbohydrate epitopes (JBC 262 (1987) 5870-5877). In addition to uronic acid and N-acetylglucosamine these glycans also contain neutral sugars, including fucose. The glycans have been postulated to mediate polyvalent carbohydrate-carbohydrate interactions (JBC 261 (1986) 2853-2859). In order to elucidate the molecular mechanism of these interactions we have purified and characterized carbohydrate epitopes from the proteoglycan. One of the oligosaccharides isolated after fragmentation of the glycans was identified as the pyruvylated trisaccharide