APLN and chronic kidney disease: Whereas infusion of [Pyr1]apelin-13 did not affect glomerular filtration rate in healthy volunteers, both low and high dose [Pyr1]apelin-13 reduced glomerular filtration rate (1 nmol/min: 41 ± 6 to 36 ± 6 mL/min; 30 nmol/min: 38 ± 5 to 34 ± 5 mL/min, p < 0.01 versus placebo for both) in patients with CKD (Fig. 2B).