Posted: July 24th, 2017

A 40-year-old woman receives an intravenous infusion of drug X that selectively constricts the efferent arterioles in her kidneys. Following the infusion, total cardiac output and renal afferent arteriolar tone are unchanged, but renal efferent arteriolar tone and total renal vascular resistance have both increased. Which of the following sets of changes most likely occurred following the infusion of drug X?

A 40-year-old woman receives an intravenous infusion of drug X that selectively constricts the efferent arterioles in
her kidneys. Following the infusion, total cardiac output and renal afferent arteriolar tone are unchanged, but renal
efferent arteriolar tone and total renal vascular resistance have both increased. Which of the following sets of
changes most likely occurred following the infusion of drug X?
Glomerular Filtration Rate Filtration Fraction Renal Blood Flow
(A) ↓ ↓ ↑
(B) ↓ ↑ ↓
(C) ↓ ↑ ↔
(D) ↑ ↓ ↔
(E) ↑ ↑ ↓