Fig. 6.

Effect of mixed AVP (V1) and CRH receptor antagonists on basal and stress-induced plasma ACTH levels. After the rats had been dialyzed with Ringer’s solution for 30 min (white horizontal bar), the antagonists were administered directly into the PVN via inverse microdialysis (hatched horizontal bar). Animals were exposed to social defeat att = 60 min for 30 min during ongoing microdialysis with either Ringer’s solution (control group) or Ringer’s solution containing the antagonists, and then tested on the elevated plus-maze (pm) for 5 min. A total of four blood samples was taken at 15, 45, 75, and 105 min after initiation of the microdialysis procedure. The pharmacological treatment caused a significant increase in basal plasma ACTH concentration (*p < 0.01 vs blood sample 1 and vs the respective blood sample of the control group). This effect remained statistically significant during social defeat and after exposure to the elevated plus-maze.