Increased response of asthmatic subjects to methacholine after influenza vaccine

Parainfluenza 3 Infection Blocks the Ability of a Beta Adrenergic Receptor Agonist to Inhibit Antigen-induced Contraction of Guinea Pig Isolated Airway Smooth Muscle

“…In preliminary experiments, it was ascertained that the maximum degree of virus infection and changes in pharmacological effects, presumably resulting from the infection, occurred 4 Effects of sulfonterol on ovalbumin-induced contraction. Dose-response curves to ovalbumin in producing a contractile response of the bronchi from guinea pigs insufflated 4 d previously with growth medium or virus suspension are illustrated in Fig.…”

“…Respiratory virus infections can exacerbate bronchial asthma (1, 2) and enhance airway reactivity to smooth muscle contractile substances (3,4). The mechanisms of these effects of virus infection have been suggested to result from antagonism of beta adrenergic or other inhibitory responses (5,6), epithelial damage resulting in sensitization of rapidly adapting airway epithelial receptors (3), and enhancement of the release of mediators of the allergic response (7).…”

The treatment of allergic rhinitis improves the recovery from asthma and upper respiratory infections

“…(13). In addition, the contribution of viral infections to the pathogenesis of airway hyperreactivity has been reported since the sixties (1,2,4,5,7,8,10,11,13,14,15).…”

Bronchial asthma of occupational origin: a review

“…Histamine also produces bronchial smooth muscle contraction which is abolished by ganglionic blockade or by atropine; this action suggests that cholinergic mechanisms are involved (45,87). Bronchoconstriction will develop to proportionally smaller concentrations of certain inhaled chemicals such as methocholine and histamine in asthmatics than in healthy individuals (45,87,92,93). It has been suggested that increased sensitivity of the "irritant" receptors could be the cause of airway hyperreactivity and it may continue even after exposure has ended.…”