Hypotensive Response to Angiotensin II Type 2 Receptor Stimulation in the Rostral Ventrolateral Medulla Requires Functional GABA-A Receptors

摘要

Figure 1. Microdialysis experiment: effect of AT2R stimulation and infusion of the AT2R agonist C21 alone (0.05 μg/μl/h) on the extracellular glutamate (Glu) (A) (n = 4) and GABA (B) (n = 6) concentrations and of co-infusion of C21 with the AT2R antagonist PD123319 (0.05 μg/μl/h) on the extracellular glutamate (Glu) (A) (n = 4) and GABA (B) (n = 5) concentrations in the RVLM in normotensive freely moving Wistar rats. Dialysates were collected every 20 min. C21 and C21 + PD123319 were dissolved in modified Ringer's solution and administered through the dialysis probe from time 120 to 240 min. Data are presented as the mean percentage of the baseline values (vehicle) ± SEM. Statistical analysis for intragroup differences of the treatment is performed using one-way ANOVA for repeated measures and the Dunnett's multiple comparison test; significant data compared to basal levels are indicated by asterisks (*p < 0.05).