To meet the extreme oxygen demand of insect flight muscle, tracheal (respiratory) tubes ramify not only on its surface, as in other tissues, but also within T-tubules and ultimately surrounding every mitochondrion. Although this remarkable physiological specialization has long been recognized, its cellular and molecular basis is unknown. Here, we show that Drosophila tracheoles invade flight mu...

Distinct parasympathetic postganglionic neurons mediate contractions and relaxations of the guinea pig airways. We set out to characterize the vagal inputs that regulate contractile and relaxant airway parasympathetic postganglionic neurons. Single and dual retrograde neuronal tracing from the airways and esophagus revealed that distinct, but intermingled, subsets of neurons in the compact form...

This study aims to investigate the role of Rho-kinase in phenotype switching and proliferation of bovine tracheal smooth muscle. To induce different phenotypic states, bovine tracheal smooth muscle strips were cultured (8 days) in 10% foetal bovine serum (foetal bovine serum, less contractile phenotype) or insulin (1 microM, hypercontractile phenotype) and compared to strips cultured in serum-f...

Inhalational insulin was withdrawn from the market due to its potential to produce airway hyper-reactivity and bronchoconstriction. So the present study was designed to explore the acute effects of insulin on airway reactivity of guinea pigs and protective effects of salbutamol and beclomethasone against insulin induced airway hyper-responsiveness on isolated tracheal smooth muscle of guinea pi...

An investigation was carried out to determine whether the sensitivity of rat tracheal smooth muscle to contractile and relaxant drugs was affected by three weeks' treatment with subcutaneous budesonide before death. Budesonide treatment was associated with a lower thymus weight and a smaller gain in body weight than in control animals. There was, however, no difference in the carbachol concentr...

The large-conductance, Ca2+-activated K+ (BK) channels are regulators of voltage-dependent Ca2+ entry in many cell types. The BK channel accessory beta1-subunit promotes channel activation in smooth muscle and is required for proper tone in the vasculature and bladder. However, although BK channels have also been implicated in airway smooth muscle function, their regulation by the beta1-subunit...

Objective In previous studies, the relaxant, anticholinergic (functional antagonism), antihistaminic and its stimulatory effects on b-adrenoceptors of Nigella sativa have been demonstrated on guinea pig tracheal chains. In the present study, the relaxant effects of hydro-ethanolic, macerated aqueous (MA) and lipid-free macerated aqueous (LFMA) extract of Nigella sativa on tracheal chains of gu...

Bronchial hyperresponsiveness is one of the main features of asthma. A nicotinic receptor agonist, 1,1-dimethylphenyl 1,4-piperazinium (DMPP), has been shown to have an inhibitory effect on airway response to methacholine in an in vivo model of asthma. The aims of this study were to 1) verify whether nicotinic acetylcholine receptors (nAChR) were present on mouse tracheal smooth muscle, 2) veri...

BACKGROUND & OBJECTIVES The biochemical mechanisms underlying the development of sensitization-induced airway hyperresponsiveness (AHR) in asthma are poorly defined. Alterations in the regulation of intracellular calcium may play an important role in its pathogenesis. We carried out this study to see the effect of sensitization with ovalbumin on membrane ion fluxes and intracellular calcium in ...