Changes in plasma levels of angiotensin II in response to stress. The plasma concentration of angiotensin II was measured by ELISA. Concentrations of angiotensin II were significantly higher in the experimental group than those in the control group from 0 days after vagal stimulation. Seven days after vagal stimulation, the concentration of angiotensin II reached its peak, and was significantly higher than at 0 days after vagal stimulation. Results are the mean ± SEM of six experiments. *P <0.05 versus control groups #P < 0.05 versus at day 0 after vagal stimulation.