Exercise Training Lowers the Enhanced Tonically Active Glutamatergic Input to the Rostral Ventrolateral Medulla in Hypertensive Rats

Yan-Ping Zha, Yang-Kai Wang, Yu Deng, Ru-Wen Zhang, Xing Tan, Wen-Jun Yuan, Xiao-Ming Deng & Wei-Zhong Wang. doi: 10.1111/cns.12065 The study investigated how exercise can modulate glutamate neurotransmission. Using WKYs and SHRs that were sedentary (sed) or exercise trained (ext) they looked basal blood pressure (BP), which was significantly reduced in the SHRs-ext when compared to the SHRs-sed. HR was also significantly reduced in the SHR-ext when compared to the SHR-sed. Similarly, they saw that exercise also reduced the decrease in BP and HR that is caused by giving a glutamate receptor blocker. Kyn had little affect ion bp and HR responses in the WKYs. In order to determine whether the concentration of glutamate is altered they used HPLC and found that SHR-sed had a higher concentration of glutamate when compared to WKYs(both sed and ext) and also SHR-ext. Western blot was done in order to examine the amount of vglut2 protein being expressed in the RVLM . Results showed that the SHR-SED had more vglut2 compared to the other groups. Finally they wanted to determine where this glutamatergic input is originating from. Western blot was done on punches from the NTS, PVN and PRF for glutaminase2. They found a significant increase in NTS and PVN in SHR-seds for glutaminase2 when compared to SHR-ext. Overall message, exercise reduces glutamatergic input via reduction in concentration of glutamate in rvlm and also a reduction in glutamatergic inputs from NTS and PVN. Maybe we should start looking at NTS also because it could be providing some glutamatergic input to rvlm.-MD