cortisol-succinate--sodium-salt and Pneumonia

Glucocorticoids (GC) remain the first choice of treatment in asthma, but GC therapy is not always effective and is associated with side effects. In a porcine study in our laboratory, simultaneous administration of GC and nitric oxide (NO) attenuated the endotoxin-induced inflammatory response and made GC treatment more effective than inhaled NO or steroids alone. In the present study, we aimed to further investigate the interactions between NO and GC treatment in two murine models of asthma. Inflammation was induced by endotoxin, ovalbumin, or a combination of both. With an animal ventilator and a forced oscillation method (FlexiVent), lung mechanics and airway reactivity to methacholine in response to various treatments were assessed. We also describe histology and glucocorticoid receptor (GR) protein expression in response to inhaled NO treatment [40 ppm NO gas or NO donors sodium nitroprusside (SNP) or diethylamine NONOate (DEA/NO)]. SNP and GC provided protection against bronchoconstriction to a similar degree in the model of severe asthma. When GC-treated mice were given SNP, maximum airway reactivity was further reduced. Similar effects were seen after DEA/NO delivery to GC-treated animals. Using 1-H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one (ODQ), a soluble guanylate cyclase inhibitor, we found this effect of NO donors to be mediated through a cGMP-independent mechanism. In the severe model, prolonged NO treatment restored or even increased the nuclear levels of GR. In conclusion, in our murine model of severe asthma GC treatment provided protection to only a limited degree against bronchoconstriction, while concomitant treatment with a NO donor was markedly more potent than the use of either NO or GC alone.

Topics: Administration, Inhalation; Animals; Anti-Asthmatic Agents; Asthma; Bronchial Provocation Tests; Bronchoconstriction; Bronchoconstrictor Agents; Cyclic GMP; Disease Models, Animal; Drug Therapy, Combination; Enzyme Inhibitors; Female; Glucocorticoids; Guanylate Cyclase; Hydrazines; Hydrocortisone; Injections, Intraperitoneal; Lipopolysaccharides; Methacholine Chloride; Mice; Mice, Inbred BALB C; Nitric Oxide; Nitric Oxide Donors; Nitroprusside; Ovalbumin; Oxadiazoles; Pneumonia; Quinoxalines; Receptors, Cytoplasmic and Nuclear; Receptors, Glucocorticoid; Respiration, Artificial; Respiratory Mechanics; Soluble Guanylyl Cyclase

Suppression of the inflammatory reaction with daily doses of cortisone acetate or cyclophosphamide substantially prolonged the pulmonary infection in mice which had been intranasally inoculated with a trachoma biotype of Chlamydia trachomatis. Titration of organisms recovered from the lungs of treated mice revealed a drop in titer after day 2 (postinfection), followed by a prominent increase on day 6. In cyclophosphamide-treated mice the infection was resolved after day 12, whereas in cortisone acetate-treated mice a significant titer remained after day 17. In contrast, no organisms were recoverable after day 6 in control mice treated with saline or in mice treated with hydrocortisone succinate. Histologically, the ability of cortisone acetate and cyclophosphamide to inhibit the inflammatory reaction correlated with the respective course of chlamydial pneumonitis. This study demonstrated that mice were intrinsically capable of sustaining a lung infection induced by a human strain of S. trachomatis.

Topics: Animals; Chlamydia Infections; Chlamydophila psittaci; Cortisone; Cyclophosphamide; Hydrocortisone; Leukocyte Count; Lung; Male; Mice; Pneumonia; Time Factors