63 research outputs found
Budesonide Foam Has a Favorable Safety Profile for Inducing Remission in Mild-to-Moderate Ulcerative Proctitis or Proctosigmoiditis
HYDROPEROXIDE-INDUCED BRONCHOCONSTRICTION AND VASOCONSTRICTION IN THE ISOLATED RAT LUNG
The effects of different hydroperoxides on lung mechanics and perfusate flow rate and their mechanisms of action were studied in isolated perfused rat lungs. The administration of hydrogen peroxide, t-butyl hydroperoxide, cumene hydroperoxide, linoleic acid hydroperoxide, and linoleic acid ethylester hydroperoxide (0.1-2 mM) to the perfusate caused a marked decreased in lung compliance, conductance, and perfusate flow rate, with constriction strength of t-butyl hydroperoxide > hydrogen peroxide > cumene hydro-peroxide > linoleic acid ethylester hydroperoxide > linoleic acid hydroperoxide. Although the hydroperoxides probably had to enter lung cells to exert their effects, no relationship was found between constriction strength and amount of hydroperoxide taken up by the lung. Reduced sensitivity was apparent after repeated dosing, depending on the length of time between dosing. The addition of the iron chelator Desferal (1 mM) had no effect on the hydroperoxide-induced broncho- and vasoconstriction, although free iron was reduced by 50% in the lungs. The administration of the antioxidants diphenyl-p-phenylenediamine (50-mu-M) or butylated hydroxyanisole (200-mu-M) to the perfusate 20 min prior to the hydroperoxide attenuated the hydroperoxide-induced effects as well as arachidonic acid-induced broncho- and vasoconstruction. Our findings have shown that hydroperoxides that can enter the lung cells will also induce both vaso- and bronchoconstriction in the isolated perfused rat lung
VASOCONSTRICTION AND BRONCHOCONSTRICTION INDUCED BY 2,5-DI-(TERT-BUTYL)1,4-BENZOHYDROQUINONE, AN ENDOPLASMIC RETICULAR CA2+-ATPASE INHIBITOR, IN ISOLATED AND PERFUSED RAT LUNG
The microsomal Ca2+-ATPase inhibitor 2,5-di-(tert-butyl)-1,4-benzohydroquinone (tBuBHQ) induced bronchoconstriction and vasoconstriction in the isolated perfused and ventilated rat lung. Thes effects were accompanied by increased levels of thromboxane and prostacyclin in the effluent perfusate. The effect of tBuBHQ was inhibited by L-655,240, a thromboxane receptor antagonist, indicating thromboxane-A2-mediated bronchoconstriction and vasoconstriction. Accordingly, the cyclooxygenase inhibitor indomethacin largely blocked the effects of tBuBHQ. The involvement of a phospholipase in the generation of thromboxane A2 (TXA2) was supported by dibucaine protection on tBuBHQ effects. The results from this study indicate that tBuBHQ, probably by inhibiting the microsomal Ca2+-ATPase, can trigger the arachidonic acid cascade leading to the formation of TXA2, which in turn causes bronchoconstriction and vasoconstriction in rat lung
SULFUR DIOXIDE-INDUCED BRONCHOCONSTRICTION IN THE ISOLATED PERFUSED AND VENTILATED GUINEA-PIG LUNG
SO2 exposure (50-500 ppm) of isolated, perfused and ventilated guinea pig lungs, via the air passages, caused a concentration-related reduction in dynamic compliance and conductance. No changes in pulmonary perfusion flow was noted at any SO2 concentration. Formed sulfite was detected in lung lavage fluid as well as in the perfusate. Pretreatment of the lungs with a low concentration of SO2 (10 ppm) for 30 min protected against bronchoconstriction by a high concentration of SO2 (250 ppm). A similar protective effect was noted by pretreatment with sodium sulfite (3 mM) in the lung perfusate
Short Inhalation Exposures of the Isolated and Perfused Rat Lung to Respirable Dry Particle Aerosols; the Detailed Pharmacokinetics of Budesonide, Formoterol, and Terbutaline
Plasma concentrations of inhaled corticosteroids in relation to airflow obstruction in asthma
Thiol modifications in H2O2 and thromboxane induced vaso-and bronchocosntriction in rat perfused lung
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