Review Question - QID 109957

A 28-year-old woman is brought to the emergency room after a motor vehicle accident. On arrival, she is stable and says that she hit a car at an intersection that "came out of nowhere". She states that she had similar close encounters with other cars these past few weeks but was able to avoid collisions with those. She has also had intermittent headaches over the last month and has noticed that her shirts have been getting wet unexpectedly. Blood tests reveal an abnormal elevation of a circulating substance. Which of following changes is also associated with the physiologic function of the most likely substance in this case?