thromboxane-b2 and Bordetella-Infections

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

Six beagles were examined for time-related changes of bronchial responsiveness to methacholine, plasma histamine and thromboxane B2, and biopsy of bronchial tissues after intratracheal injection of Bordetella bronchiseptica. A progressive increase in bronchial responsiveness was induced after injection. The mediators, however, did not elevate and tissue neutrophil counts did not correlate with increased airway hyperresponsiveness. Intratracheal injection of heat-killed Bordetella bronchiseptica produced no alteration in these parameters. Thus, it is speculated that airway epithelial damage and effects on ciliostatic function induced by the organism are primarily involved in the pathogenesis.

Topics: Animals; Biopsy; Bordetella Infections; Bronchi; Bronchial Diseases; Bronchial Provocation Tests; Dogs; Female; Histamine; Leukocyte Count; Methacholine Chloride; Methacholine Compounds; Neutrophils; Respiratory Hypersensitivity; Thromboxane B2