Cardiovascular & General

Apelin

Apelin does two things at once that rarely travel together: it relaxes blood vessels through nitric oxide, and it makes heart muscle contract harder. That combination is why cardiologists went to the trouble of measuring it directly, threading pressure and Doppler wires into the coronary arteries of patients and infusing it during randomised, double-blind, placebo-controlled sessions. In eighteen patients with chronic heart failure the biology held: blood flow rose, cardiac index rose, mean arterial pressure fell. Those sessions lasted minutes to hours, and no study on file has given apelin for any longer, or asked whether a single patient felt better, stayed out of hospital, or lived longer.

Last updated 12 August 2026

Studied forCardiac contractility research · Vasodilation research · Heart failure context

Evidence on file2 animal studies · 2 citations not yet graded

Strongest sourceApelin, a Newly Identified Adipokine Up-Regulated by Insulin and Obesity (Endocrinology 2005, cited 727x) (animal study)

Mechanism

Activates the APJ receptor, producing endothelium- and nitric-oxide-dependent vasodilation and positive inotropic effects on cardiomyocytes.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

Cardiac contractility research
Vasodilation research
Heart failure context

Dosing on file unverified

IV: 1, 10, 100 nmol/min escalating; 30 nmol/min; Intra-arterial: 0.3, 1.0, 3.0 nmol/min; 30, 100, 300 nmol/min × 5min; Intra-arterial: 0.1, 1.0, 3.0 nmol/min × 6min; [Pyr1]apelin-13: 1 or 10 nmol/mL × 3h

Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.

Literature on file 4

animal in vivo
Apelin, a Newly Identified Adipokine Up-Regulated by Insulin and Obesity (Endocrinology 2005, cited 727x) graded on: an animal model — read from the indexed abstract — “mice”
animal in vivo
Apelin, the Novel Endogenous Ligand of the Orphan Receptor APJ, Regulates Cardiac Contractility (Circulation Research 2002, cited 525x) graded on: an animal model — read from the indexed abstract — “rats”

Not graded

2 citations whose study design could not be read from the title. Left ungraded rather than guessed at.

not graded
NCT00901719: Investigating the Interaction of Apelin and Systemic Angiotensin II Peripheral Resistance Vessels and Systemic Haemodynamics in Vivo in Man graded on: NCT00901719 is completed and has posted no results - a registration, not a reported outcome — “NCT00901719”
not graded
NCT02150694: Local Haemodynamic Effects of Apelin Agonists and Antagonists in Man in Vivo graded on: NCT02150694 is completed and has posted no results - a registration, not a reported outcome — “NCT02150694”

Identity

Space-filling 3D model of Apelin, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Apelin — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 6156
Molecular formula: C266H427N95O71S2
CAS number: 372170-33-7
PubChem CID: 56841713
UniProt: Q9ULZ1 (precursor)
InChI key: BWVPHIKGXQBZPV-QKFDDRBGSA-N
SMILES: CC(C)C[C@@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC(=O)O)C(=O)NCC(=O)N[C@@H](CC(=O)N)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC1=CN=CN1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CCC(=O)N)C(=O)N2CCC[C@H]2C(=O)N[C@@H](CCCNC(=N)N)C(=O)NCC(=O)N[C@@H](CO)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(=O)N)C(=O)NCC(=O)N3CCC[C@H]3C(=O)NCC(=O)N4CCC[C@H]4C(=O)N[C@@H](CC5=CNC6=CC=CC=C65)C(=O)N[C@@H](CCC(=O)N)C(=O)NCC(=O)NCC(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC7=CC=CC=C7)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N8CCC[C@H]8C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CO)C(=O)N[C@@H](CC9=CN=CN9)C(=O)N[C@@H](CCCCN)C(=O)NCC(=O)N1CCC[C@H]1C(=O)N[C@@H](CCSC)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CC1=CC=CC=C1)C(=O)O)NC(=O)CNC(=O)[C@H](CC(=O)N)NC(=O)CNC(=O)[C@H](CC(=O)O)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CC(C)C)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CCSC)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)CN
InChI: InChI=1S/C266H427N95O71S2/c1-135(2)102-166(318-201(374)123-309-216(390)174(112-195(273)368)319-202(375)124-311-219(393)178(116-210(385)386)348-247(421)189-68-45-99-361(189)256(430)179(106-139(9)10)349-248(422)190-69-43-97-359(190)254(428)164(79-100-433-15)336-231(405)167(103-136(3)4)341-240(414)181(130-362)321-198(371)117-269)230(404)331-161(74-78-208(381)382)229(403)346-177(115-209(383)384)218(392)310-125-203(376)320-176(114-197(275)370)238(412)353-211(140(11)12)250(424)334-158(61-36-90-303-265(290)291)227(401)343-173(111-146-120-295-134-316-146)236(410)340-169(105-138(7)8)237(411)352-212(141(13)14)251(425)338-163(73-77-194(272)367)253(427)358-96-42-66-187(358)245(419)332-150(54-29-83-296-258(276)277)213(387)308-126-204(377)322-182(131-363)239(413)328-156(59-34-88-301-263(286)287)225(399)345-175(113-196(274)369)217(391)313-128-205(378)354-92-38-63-184(354)242(416)314-129-207(380)356-94-40-65-186(356)244(418)347-171(109-144-118-305-148-51-24-23-50-147(144)148)234(408)329-159(71-75-192(270)365)215(389)307-121-199(372)306-122-200(373)317-151(55-30-84-297-259(278)279)220(394)325-153(56-31-85-298-260(280)281)221(395)324-152(53-26-28-82-268)224(398)342-170(107-142-46-19-17-20-47-142)233(407)327-155(58-33-87-300-262(284)285)222(396)326-154(57-32-86-299-261(282)283)223(397)330-160(72-76-193(271)366)228(402)335-162(62-37-91-304-266(292)293)252(426)357-95-41-67-188(357)246(420)333-157(60-35-89-302-264(288)289)226(400)339-168(104-137(5)6)232(406)351-183(132-364)241(415)344-172(110-145-119-294-133-315-145)235(409)323-149(52-25-27-81-267)214(388)312-127-206(379)355-93-39-64-185(355)243(417)337-165(80-101-434-16)255(429)360-98-44-70-191(360)249(423)350-180(257(431)432)108-143-48-21-18-22-49-143/h17-24,46-51,118-120,133-141,149-191,211-212,305,362-364H,25-45,52-117,121-132,267-269H2,1-16H3,(H2,270,365)(H2,271,366)(H2,272,367)(H2,273,368)(H2,274,369)(H2,275,370)(H,294,315)(H,295,316)(H,306,372)(H,307,389)(H,308,387)(H,309,390)(H,310,392)(H,311,393)(H,312,388)(H,313,391)(H,314,416)(H,317,373)(H,318,374)(H,319,375)(H,320,376)(H,321,371)(H,322,377)(H,323,409)(H,324,395)(H,325,394)(H,326,396)(H,327,407)(H,328,413)(H,329,408)(H,330,397)(H,331,404)(H,332,419)(H,333,420)(H,334,424)(H,335,402)(H,336,405)(H,337,417)(H,338,425)(H,339,400)(H,340,410)(H,341,414)(H,342,398)(H,343,401)(H,344,415)(H,345,399)(H,346,403)(H,347,418)(H,348,421)(H,349,422)(H,350,423)(H,351,406)(H,352,411)(H,353,412)(H,381,382)(H,383,384)(H,385,386)(H,431,432)(H4,276,277,296)(H4,278,279,297)(H4,280,281,298)(H4,282,283,299)(H4,284,285,300)(H4,286,287,301)(H4,288,289,302)(H4,290,291,303)(H4,292,293,304)/t149-,150-,151-,152-,153-,154-,155-,156-,157-,158-,159-,160-,161-,162-,163-,164-,165-,166-,167-,168-,169-,170-,171-,172-,173-,174-,175-,176-,177-,178-,179-,180-,181-,182-,183-,184-,185-,186-,187-,188-,189-,190-,191-,211-,212-/m0/s1

Notes unverified prose

Multiple Phase 1 human studies; NCT00901719; NCT02150694; Phase 1 human studies

Not on file 2

1 of the 8 fields we track hold nothing on this record, and each says why. 1 further absence is named below. A blank field is a bug; a named absence is a finding.

amino-acid sequencenothing we hold supplies it
half-lifenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.