Question: why does anp increase gfr?
Answer: ANP increases glomerular filtration rate. ANP increases glomerular filtration rate (GFR) through its direct vasodilata- tion effects on the afferent arterioles, which allows more blood to enter the glomerulus for ultrafiltration. ANP also reverses afferent arteriolar vasoconstriction induced by norepinephrine (37, 60).