thromboxane-b2 and Paramyxoviridae-Infections

The influence of parainfluenza type 3 (PI-3) virus on the release of inflammatory mediators by guinea pig pulmonary alveolar macrophages (PAMs) was investigated in vitro. Direct application of PI-3 virus dose-dependently stimulated the generation of chemiluminescence by PAMs and induced aggregation of PAMs. No significant effects of PI-3 virus on the release of linoleic acid metabolites by PAMs were detected. However, an increased release of the arachidonic acid metabolite thromboxane B2 (TxB2) was observed when PAMs were stimulated with PI-3 virus. PAMs were also cultured for 2 h or 18 h in the presence of PI-3 virus or control medium. The production of reactive oxygen species and the release of fatty acid metabolites by these PAMs were determined upon stimulation with opsonized zymosan particles or phorbol myristate acetate. The amounts of hydrogen peroxide and superoxide produced did not differ between virus- and control medium-incubated PAMs. However, the PI-3 virus-treated PAMs generated twice as much chemiluminescence when compared to PAMs incubated with control medium. The 2-h incubation period with PI-3 virus also resulted in a decreased release of TxB2 from the PAMs upon zymosan stimulation. The changes in the production of reactive oxygen species and the release of TxB2 by PAMs could account for damage to the airways and bronchial hyperresponsiveness often seen after viral infection.

Topics: Animals; Arachidonic Acid; Cell Aggregation; Guinea Pigs; Hydrogen Peroxide; In Vitro Techniques; Linoleic Acid; Linoleic Acids; Luminescent Measurements; Macrophages, Alveolar; Male; Parainfluenza Virus 3, Human; Paramyxoviridae Infections; Reactive Oxygen Species; Superoxides; Thromboxane B2

Acute infections in beagle puppies with canine parainfluenza virus type 2 (CP12), and CP12 in combination with Bordetella bronchiseptica (Bb) produce bronchiolitis and increased airways responsiveness to aerosolized histamine during the acute infection. In order to determine whether these observations were associated with increased levels of eicosanoids, the stable metabolites of thromboxane A2 and prostacylin, thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha) respectively, and leukotriene B4 were measured in the bronchoalveolar lavage (BAL) fluid of 25 beagle puppies (age = 76 +/- 1 days, mean +/- SEM) 3-4 days after no infection (control, n = 6), inoculation with both CP12 and Bb (CP12-Bb, n = 11), inoculation with CP12 alone (CP12, n = 4), and inoculation with Bb alone (Bb, n = 4). In addition, plasma levels of TXB2 and 6-keto-PGF1 alpha were measured before and after infection in the CP12-Bb and control groups. The BAL concentration of thromboxane B2 was increased in the CP12-Bb group (520 +/- 120 pg/ml), but not in the CP12 (88 +/- 40 pg/ml), Bb (235 +/- 100 pg/ml), or control groups (120 +/- 60 pg/ml, p less than 0.01). There also was a borderline increase in BAL concentration of LTB4 in the CP12-Bb group. No differences were observed in the BAL concentration of 6-keto PGF1 alpha. Furthermore, neither TXB2 nor PGF1 alpha was elevated in the plasma of control or CP12-Bb puppies. These data suggest that increased thromboxane concentrations in BAL fluid are associated with histamine hyperresponsiveness during acute infection in the CP12-Bb group.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bordetella Infections; Bronchoalveolar Lavage Fluid; Dogs; Leukotriene B4; Parainfluenza Virus 2, Human; Paramyxoviridae Infections; Thromboxane B2