Table 1

Overview of direct and indirect stimuli

Indirect stimuliDirect stimuli
Physical stimuliCholinergic agonists
 Exercise(acetylcholine,
 Nonisotonic aerosolsmethacholine,
(hyper-, hypotonic,carbachol)
distilled waterHistamine
aerosols, mannitol)Prostaglandin D2
 Eucapnic voluntary hyperpnoea of dry airLeukotriene C4/D4/E4
Pharmacological stimuli
 Adenosine
 Tachykinins
 Bradykinin
 Metabisulphite/SO2
 Propranolol
Endotoxin (LPS)
Platelet activating factor
Ozone
Selective agents
 Aspirin and NSAID
 Allergen
  • LPS: lipopolysacharides

  • NSAID: nonsteroidal anti-inflammatory drugs

  • SO2: sulphur dioxide