A patient appears to have “white coat” hypertension- very highblood pressure when they come to the doctor’s office. When they arerelaxed at home, blood pressure is fairly normal. Blood tests showthat the patient has high sodium levels and low potassiumlevels during these periods of hypertension. Additionally,the patient’s medical records also showed that blood pressure risesunusually during fasting and illness as well, andthat they had to stop taking an anti-inflammatorydrug due to hypertension as a side effect. The physiciantalks to a colleague who is an endocrinologist specializing ingenetics (to the rescue!).

The endocrinologist concluded that the patient might haveinherited a mutation that affects the activity of a steroid hormonereceptor (Receptor A) that binds to a steroidhormone (Hormone A) that plays an important rolein blood pressure regulation. She found that the patient has amutation that allows Receptor A to be activatedeven better by a second, related steroid HormoneB. Hormone B can now, by accident,strongly activate Receptor A even within thenormal range of blood levels regulated by its negative feedbackloop.

• Hormone A: What is Hormone A? What regulatesits secretion? What cells secrete it? What is its normalphysiological role?
• Hormone B: What is Hormone B? What regulatesits secretion? What cells secrete it? What is its normalphysiological role?