The objective of the present study is to obtain information about the safety and tolerability of BIIX 1 XX, to determine the pharmacologically active dose (range) by performing a methacholine challenge test and to obtain preliminary pharmacokinetic data

Inclusion Criteria:

• Healthy male volunteers who have Broca-Indices within +-20%
• Participants in the age range between 21 to 50 years
• Following the methacholine challenge the airway resistance (Raw) shows an increase of at least 130%
• In accordance with Good Clinical Practice (GCP) and local legislation each volunteer is supposed to give his written informed consent prior to admission to the study
• As part of the screening (within 14 days before drug administration), each subject was to receive a complete medical examination (including blood pressure, pulse rate, medical history, documentation of demographics, inclusion/exclusion criteria and concomitant therapy) as well as a 12-lead Electrocardiogram (ECG)
• Haematopoietic, hepatic and renal function test will be carried out in the laboratory
• The subjects will fast for 12 hours before collection of specimens for all laboratory evaluations. The above mentioned examinations will be performed within 14 days before the first administration of the test substance

Exclusion Criteria:

• Volunteers will be excluded from the study if the results of the medical examination or laboratory tests are judged by the clinical investigator to differ significantly from normal clinical values
• Volunteers with known gastrointestinal, hepatic, renal, respiratory, cardiovascular, metabolic, immunological or hormonal disorders
• Volunteers with diseases of the central nervous system (such as epilepsy) or with psychiatric disorders
• History of orthostatic hypotension, fainting spells or blackouts
• Chronic or relevant acute infections
• History of allergy/hypersensitivity (including drug allergy) which is deemed relevant to the trial as judged by the investigator
• Intake of a drug with a long half-life (>= 24 hours) within one month before enrolment in the study
• Use of any drugs which might influence the results of the trial the week previous to the start of the study
• Participation in another study with an investigational drug within the last two months preceding this study
• Smoker (> 10 cigarettes or 3 cigars or 3 pipes/day)
• Inability to refrain from smoking on study days
• Alcohol abuse (> 60g/day)
• Drug abuse
• Blood donation within the last 4 weeks
• Excessive physical activities within the last week before the study