Which of the following substances is excreted by the kidneys to regulate blood pressure?
A. renin
B. erythropoien
C. calcitriol
D. urobilinogen
The kidneys secrete a number of hormones, which are important for normal functioning of the body.
If blood pressure falls, renin is secreted by the kidneys to constrict the small blood vessels, thereby increasing blood pressure. If the kidneys aren’t functioning correctly, too much renin can be produced, increasing blood pressure and sometimes resulting in hypertension (high blood pressure). This is why a number of people with kidney diseases also have high blood pressure.
Therefore, the Correct Answer is A.