OBJECTIVE Hyperpolarization modulates Ca2+ influx during agonist stimulation in many endothelial cells, but the effects of hyperpolarization on Ca2+ influx in freshly isolated arteriolar endothelial cells are unknown. Therefore, the purpose of the present study was to characterize agonist-induced Ca2+ transients in freshly isolated arteriolar endothelial cells and to test the hypothesis that me...

BACKGROUND There is increasing evidence that wheezing during childhood may be a heterogeneous condition, and that different forms of wheezing may be associated with different risk factors and prognosis. The aim of this study was to determine if measures of airway lability and of atopy could identify distinct wheezing phenotypes during childhood. METHOD In a cohort of children followed from bi...

Background—In vitro the long acting â2 agonist salmeterol can, in contrast to formoterol, behave as a partial agonist and become a partial antagonist to other â2 agonists. To study this in vivo, the bronchodilating eVect of salbutamol was measured during methacholine induced moderate to severe bronchoconstriction in patients receiving maintenance treatment with high dose long acting â2 agonists...

Usually, hyperresponsiveness to inhaled methacholine is considered closely associated with a diagnosis of bronchial asthma. Recently, it has been clearly pointed out that bronchial hyperreactivity (BHR) is not a constant feature of asthma and that this condition is not always related to airways inflammation. In the present study we evaluated 42 Patients (21 positive and 21 negative for bronchia...

A plethysmographic method was employed to assess the airway resistance of conscious, free-breathing guinea-pigs. Using this method animals sensitized by inhalation of ovalbumin and appropriate controls were assessed for their responsiveness to histamine and methacholine in vivo. The cough frequency on exposure to citric acid mist in the two groups was also assessed. Tracheal spirals from these ...

Asthma is a complex disease of airway inflammation, which results in airway remodeling and hyper-responsiveness.1 Because asthma-related symptoms are not specific to asthma, diagnosis requires objective data from pulmonary function tests (PFT). Bronchodilator responsiveness and airway responsiveness to provocational stimuli (eg, methacholine, dry-gas hyperpnea) help establish the diagnosis of a...

Seventy-eight ocular hypertensive patients and 47 age-and sex-matched control subjects were assessed for parasympathetic denervation hypersensitivity of the iris using topical application of 2.5% methacholine chloride solution. Constriction of the pupil in response to methacholine stimulation of the sphincter pupillae was significantly greater in the ocular hypertensive patients than the contro...

Major basic protein and other native cationic proteins increase airway hyperresponsiveness when administered to the luminal surface of the airways in vitro. To determine whether the same applies in vivo, we assessed airway responsiveness in rats challenged with both aerosolized and intravenously infused methacholine. We partitioned total lung resistance into its airway and tissue components usi...