The role of opioidergic and GABAergic systems in the mechanosensitivity regulation of the respiratory system in rats

Abstract

In anaesthetized white outbred male rats we investigated the change of respiratory mechanoreceptors sensitivity to morphine and phenibut. Bilateral transection of the vagus nerves causes a severely slowdown of respiratory rate in 30 minutes after the systemic administration of morphine, however after administration of phenibut the respiratory rate and other respiration parameters have not changed significantly. It means that the activation of opioid receptors by morphine does not significantly affect the function of the respiratory mechanoreceptor control loop, and transection of the vagus nerves on this background increases the probability of respiratory rhythm disorders. Activation of GABAergic system by phenibut significantly weakened the impact of the regulating contour of the respiratory mechanoreceptor on breathing parameters, up to effect of "central vagotomy": that is, to no changes in respiratory parameters after cutting the vagus nerves