Contribution of retrotrapezoid nucleus neurons to CO2 -amplified cardiorespiratory activity in spontaneously hypertensive rats.

This study demonstrates that CO2 -induced both respiratory and cardiovascular responses are augmented in spontaneously hypertensive rats (SHRs). Genetic ablation of the retrotrapezoid nucleus (RTN) neurons depresses enhanced hypercapnic ventilatory response and eliminates CO2 -stimulated increase in arterial pressure and heart rate in SHRs. SHRs have high protein level of pH-sensitive channels in the RTN, including TASK-2 channel, Kv12.1 channel and acid-sensing ion channel 3. The inhibition of putative TASK-2 channel activity by clofilium diminishes amplified hypercapnic ventilatory and cardiovascular responses, and reduces the number of CO2 -activated RTN neurons in SHRs. These results indicate that RTN neurons contribute to enhanced CO2 -stimulated respiratory and cardiovascular responses in SHRs. ABSTRACT: The respiratory regulation of cardiovascular activity is essential for maintaining efficient ventilation and perfusion ratio. Activation of central respiratory chemoreceptors not only elicits a ventilatory response but also regulates sympathetic nerve activity and arterial blood pressure (ABP). The retrotrapezoid nucleus (RTN) is the most completely characterized cluster of central respiratory chemoreceptors. We hypothesize that RTN neurons contribute to augmented CO2 -stimulated respiratory and cardiovascular responses in adult spontaneously hypertensive rats (SHRs). Our findings indicate that SHRs exhibit enhanced hypercapnic cardiorespiratory responses than age-match...

Source: The Journal of Physiology - December 21, 2020 Category: Physiology Authors: Tian Y, Geng D, Wang Y, Shi L, Yu H, He W, Zhu Y, Jun S, Fu C, Wang X, Zhang X, Yuan F, Wang S Tags: J Physiol Source Type: research