Role of reactive oxygen species in regulation of respiratory rhythm in medial area of nucleus retrofacialis / 第二军医大学学报

ABSTRACT

Objective: To explore the role of reactive oxygen species (ROS, i. e, H2O2 and O2-) in regulation of respiratory rhythm in the medial area of nucleus retrofacialis (mNRF). Methods: Medullary slices of neonatal SD rats, including hypoglossal nerve (XII n) and mNRF, were made according to Suzue's method. Simultaneous recording of the XII n respiratory rhythmic activity (RRA) with suction electrode and the respiratory neuronal discharge were performed with whole cell patch in the mNRF on the brainstem slice in vitro. The effect of t-butyl hydroperoxide (tBHP) and α-lipoic acid (α-LA) on the respiratory pacemaker neurons and respiratory rhythm in the mNRF were observed. Results: tBHP significantly decreased respiratory cycle (RC) and increased respiratory amplitude; α-LA significantly increased RC and decreased its amplitude. Meanwhile, α-LA significantly prolonged the action potential of the respiratory cadmium-insensitive pacemaker neurons and reduced its amplitude, but it had no significant effect on the cadmium-sensitive respiratory pacemaker neurons. Voltage steps and ramps showed that α-LA inhibited both the transient and persistent sodium current of cadmium-insensitive pacemaker neurons. Conclusion: ROS has an excitatory effect on the respiratory rhythm and the cadmium-insensitive respiratory pacemaker neurons through modulating sodium current.