The Austrian Pneumological Society held its 33th Workshop on "Clinical Respiratory Physiology" at Graz, November 1 st -3rd, 1990. Bronchial hyperresponsiveness has been known nearly as long as asthma bronchia Ie itself. During the last two decades while exploring the inflammatory nature of asthma bronchiale we have learned a lot about measuring and modifying this phenomenon. Because of the practical relevance and owing to the high competence of the authors we hope that the lectures and discussions we had at Graz will inform and enjoy the interested reader. I want to express my deep gratitude to all the authors for providing us with the manuscripts and graphs. Finally I am especially grateful to Mrs. H. Weber for her secreterial work and to Mrs. Mag. A. Lahrmann-Ramharter for correcting the written version of the speeches and preparing a manuscript that was ready for the press. Prim. Dr. Hartmut Zwick Contents Barnes P. : Cellular and Biochemical Aspects of Airway Hyperresponsiveness. . . . . . . . . . 1 Hargreave F. E. : Airway Hyperresponsiveness and Asthma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Ingram R. H. : Physiologic Correlates of Increased Airway Responsiveness . . . . . . . . . . . . . . . . 36 K errebijn K F. : Bronchial Provocation Testing in Children -Methods and Clinical Relevance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Tattersfield A. E. : Bronchial Provocation Testing in Adults -Is There Clinical Relevance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Kummer F. : Principles and Approaches in Asthma Therapy. . . . . . . . . . . . . . . . . . . . . . . . . .