Oxidative stress in the rostral ventrolateral medulla modulates excitatory and inhibitory inputs in spontaneously hypertensive rats

J Hypertens. 2012 Jan;30(1):97-106.  

Nishihara M, Hirooka Y, Matsukawa R, Kishi T, Sunagawa K.

This study aims at answering 3 important questions.

1. Determine whether chronic oxidative stress in the RVLM alters synaptic transmission through glutamatergic inputs.

2. Determine whether chronic oxidative stress in the RVLM alters synaptic transmission through GABA-ergic inputs.

3.  Determine whether chronic oxidative stress in the RVLM alters synaptic transmission through excitatory inputs from the PVN.

Adenoviral vectors encoding MnSOD was transferred into the RVLM of male SHRs and WKYs. Microinjection studies using Kynurenic acid (Glutamate receptor antagonist) and Bicuculline (GABA receptor antagonist) showed that reactive oxygen species (ROS) in the RVLM enhanced the excitatory glutamatergic inputs and reduced the GABAergic inputs to the RVLM neurons in SHRs. In addition, activation of the PVN neurons enhanced the pressor and sympathoexcitation through ROS in the RVLM. These findings suggest that ROS in the RVLM increases glutamatergic excitatory inputs and decreases GABAergic inputs in SHRs.

Madhan