{{infokutija protein
| Ime = RVD-Hpα fragment hemoglobina (pepkan-12), alfa 1
| caption = Polipeptidni fragment izveden iz ostataka  92-104 (RVDPVNFKLLSH) u ljudskoj sekvenci
| image = 
| width = 
| CAS_number = 1193362-76-3 
| HGNCid = 4823
| Symbol = [[Hemoglobin, alpha 1|HBA1]]
| AltSymbols = 
| EntrezGene = 3039
| OMIM = 141800
| RefSeq = NM_000558
| UniProt = P69905
| PDB = 
| ECnumber = 
| Chromosome = 16
| Arm = p
| Band = 13.3
| LocusSupplementaryData = 
}}
'''RVD-Hpα''' (pepkan-12) je endogeni [[neuropeptid]] pronađen u mozgu čovjeka i ostalih sisara, za koji je prvobitno predloženo da djeluje kao selektivni [[agonist]] za [[kanabinoidni receptor 1|CB<sub>1</sub>]] [[kanabinoidni receptor]]. To je 12-[[aminokiselina|aminokiselinski]]  [[polipeptid]] koji ima aminokiselinsku sekvencu Arg-Val-Asp-Pro-Val-Asn-Phe-Lys-Leu-Leu-Ser-His i predstavlja prošireni oblik [[N-kraj]]a [[hemopresin]]a, 9-AA polipeptida izvedenog iz [[hemoglobin| α <sub>1</sub>]] podjedinice [[hemoglobin]]a, koja je prethodno bila predstavljana da djeluje kao inverzni agonist CB<sub>1</sub>.<ref>{{cite journal | vauthors = Heimann AS, Gomes I, Dale CS, Pagano RL, Gupta A, de Souza LL, Luchessi AD, Castro LM, Giorgi R, Rioli V, Ferro ES, Devi LA | title = Hemopressin is an inverse agonist of CB1 cannabinoid receptors | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 104 | issue = 51 | pages = 20588–93 | date = December 2007 | pmid = 18077343 | pmc = 2154475 | doi = 10.1073/pnas.0706980105 | bibcode = 2007PNAS..10420588H }}</ref> Sva tri polipeptida su izolirana od različitih vrsta sisara, pri čemu je RVD-Hpα jedan od obilnijih neuropeptida izraženih u [[miš]]jem [[mozak|mozgu]], a ovi neuropeptidi predstavljaju novi put za kanabinoidna istraživanja, različita od ranije poznatih endogenih [[lipid]]no-izvedeni kanabinoidnih agonista, kao što je [[anandamid]].<ref>{{cite journal | vauthors = Gomes I, Grushko JS, Golebiewska U, Hoogendoorn S, Gupta A, Heimann AS, Ferro ES, Scarlata S, Fricker LD, Devi LA | title = Novel endogenous peptide agonists of cannabinoid receptors | journal = FASEB Journal | volume = 23 | issue = 9 | pages = 3020–9 | date = September 2009 | pmid = 19380512 | pmc = 2735371 | doi = 10.1096/fj.09-132142 }}</ref> Nedavno je pokazano da je RVD-Hpα (koji se također naziva pepkan-12) moćan negativni alosterski modulator na receptorima CB <sub>1</sub>, zajedno s drugim novoopisanim N-terminalno produženim peptidima (pepkanima).<ref>{{cite journal | vauthors = Bauer M, Chicca A, Tamborrini M, Eisen D, Lerner R, Lutz B, Poetz O, Pluschke G, Gertsch J | title = Identification and quantification of a new family of peptide endocannabinoids (Pepcans) showing negative allosteric modulation at CB1 receptors | journal = The Journal of Biological Chemistry | volume = 287 | issue = 44 | pages = 36944–67 | date = October 2012 | pmid = 22952224 | pmc = 3481297 | doi = 10.1074/jbc.M112.382481 }}</ref><ref name="Macedonio`-2016">{{cite journal | vauthors = Macedonio G, Stefanucci A, Maccallini C, Mirzaie S, Novellino E, Mollica A | title = Hemopressin Peptides as Modulators of the Endocannabinoid System and their Potential Applications as Therapeutic Tools | journal = Protein and Peptide Letters | volume = 23 | issue = 12 | pages = 1045–1051 | year = 2016 | pmid = 27748182 | doi = 10.2174/0929866523666161007152435 }}</ref>