Investigation of the Role of AT2 Receptors in the Nucleus Tractus Solitarii of Normotensive Rats in Blood Pressure Control

摘要: Aim The nucleus tractus solitarii (NTS) densely expresses angiotensin II type 2 receptors (AT2R), which are mainly located on inhibitory gamma-aminobutyric acid (GABA) neurons. Central AT2R stimulation reduces blood pressure, and in the rostral ventrolateral medulla (RVLM), mediates a hypotensive response through GABAergic mechanism. We aimed to test hypothesis that an mediated inhibition of GABA release within NTS might be involved this response, by assessing possible alterations pressure heart rate, as well levels normotensive Wistar rats. Methods In vivo microdialysis was used for measurement extracellular perfusion selective agonist, Compound 21, NTS. Our set-up allowed determine simultaneously excitatory glutamate dialysate levels. mean arterial rate responses were monitored with transducer. Results Local 21 into did not modify nor compared baseline concentrations. A putative effect also unmasked concomitant 1 receptor blockade candesartan. Positive control experiments confirmed experimental set up had enough sensitivity detect reduction pressure. Conclusion results provide evidence role interaction local signaling