Asthmatic Augmentation of Airway Vagal Activity Involves Decreased Central Expression and Activity of CD73 in Rats

The severity of asthma is closely related to the intensity of airway vagal activity; however, it is unclear how airway vagal activity is centrally augmented in asthma. Here we report that in an asthma model of male Sprague–Dawley rats, the expression and activity of ecto-5′-nucleotidase (CD73) were decreased in airway vagal centers, ATP concentration in cerebral spinal fluid was increased, and the inhibitory and excitatory airway vagal responses to intracisternally injected ATP (5 μmol) and CD73 inhibitor AMPCP (5 μmol), respectively, were attenuated. In airway vagal preganglionic neurons (AVPNs) identified in medullary slices of neonatal Sprague–Dawley rats, AMPCP (100 μmol·L–1) caused excitatory effects, as are shown in patch-clamp by depolarization, increased neuronal discharge, and facilitated spontaneous excitatory postsynaptic currents (sEPSCs). In contrast, exogenous ATP (100 μmol·L–1, 1 mmol·L–1) primarily caused inhibitory effects, which are similar to those induced by exogenous adenosine (100 μm...