Heart rate, blood pressure, ECGs, FEV1 and exhaled nitric oxide were measured pre dose on days 1 and 7, and at 1 hr post dose. On day 7, an inhaled allergen challenge was subsequently performed after the 1 hour post dose FEV1 and FeNO measure ments. Methacholine challenge was then performed at 24 hours post allergen challenge. selleck chem Adverse events and beta agonist use were monitored throughout the study with the aid of diary cards. Allergen and Methacholine Challenges Inhibitors,Modulators,Libraries Bronchial challenges were performed as we have pre viously described using a Mefar Dosimeter. Allergen for skin prick tests Ltd was stored at 4 C. each subject was assessed for sensitivity to house dust mite, cat, grass pollen, and positive and negative controls. The allergen for inhalation was selected according to the largest skin test wheal and clinical history.

Fresh solutions of allergen were made up in 0. 9% saline in doubling concentrations from 250 SQ U/ml to 32 000 SQ U/ml. At screening, incremental doses of allergen were Inhibitors,Modulators,Libraries inhaled until an early asthmatic response was observed, defined as a fall in FEV1 of 20% from the post saline value, on at least one occasion, between 5 and 30 minutes after the final concentration of allergen. The late asthmatic response was defined as a fall in FEV1 of 15% from the post saline value, on at least three occasions, two of which must be consecutive, between 4 and 10 hours after the final con centration of allergen. During the treatment periods, the total dose of allergen required to cause an EAR and LAR was administered as a single bolus dose.

Subjects were administered doubling concentrations of methacholine from 0. 03125 to 32 mg/ml until a 20% fall in FEV1 was achieved or the highest concentration of methacholine was administered. The provocative con centration required to reduce Inhibitors,Modulators,Libraries the FEV1 by 20% of the post saline baseline value was derived by linear interpolation between the lowest concentration that caused a 20% fall and the preceding concentration. If the FEV1 did not fall by more than 20% following the highest concentration then the PC20 was set to the highest concentration given in the challenge. If the FEV1 fell by more than Inhibitors,Modulators,Libraries 20% following the first concentration the PC20 was derived as. FeNO FeNO was measured using the Ecomedics AG analyser CLD 88 at a flow of 50 ml/s. Three acceptable readings were recorded from each subject and the mean was used for analysis. Pharmacokinetic Sampling and Bioanalytical Method On days 1 and 7, blood samples were collected at pre dose. The active metabolite GSK614917, which is 1. 7 Inhibitors,Modulators,Libraries fold less selleck chemical potent than the parent compound, was also measured. These pharmacokinetic analyses were performed by protein precipitation, fol lowed by HPLC/MS/MS.