| Kitsize | 12x8 |
| Method | ELISA |
| Incubationtime | 1x1h,1x10min |
| Standardrange | 25-2500pg/mL |
| Specimen/Volumes | 50µLserum/withoutextraction |
| Substrate/isotope | TMB450nm |
| RegulatoryStatus: | EU:CE,CDN:IVD |
IBLInternationalofferstheonlyworldwidecommerciallyavailabledirectELISAformeasuring5α–Dihydrotestosterone(DHT)inserum.Resultscanbeobtainedwithin1.5hours.MeasuringDHTlevelsfindsitsapplicationingynecology,pediatrics,endocrinologyandbiochemistry.
AndrogenicSteroid
DHTisessentialforthedevelopmentofthemalesexcharacteristicsbeforebirth,particularlytheformationoftheexternalgenitalia.Intheadult,DHTisneededtodevelopandmaintainmalegendercharacteristics,suchasfacialhair,deepvoice,andmusclegrowth.Inwomen,DHTmayinducetheonsetofpubertyandcausesthebodyandpubichairgrowth.
Inmales,about70%ofDHTisderivedfromconversionoftestosteroneby5α–Reductaseintheprostate,testes,hairfollicles,andadrenalglands.InfemalesmostoftheDHTisderivedfromandrostenedione.DHThasapproximately3timesgreateraffinityforandrogenreceptorsthantestosteroneandhas15-30timesgreateraffinitythanadrenalandrogens.
DHTPathologies
5α–Reductasedeficiencycanresultinpseudo–hermaphroditism.DHTistheprimarycontributingfactorinmalepatternbaldnessandmaycontributetothedevelopmentofbenignprostatichyperplasia,aswellasprostatecancer.WomenwithincreasedlevelsofDHTmaysufferfromfemaleandrogenismbydevelopingandrogynoussecondarysexcharacteristics.
Synonyms
Androstanolone(5α–Androstan–17β–ol–3–one)
17β–hydroxy–5α–Androstan–3–one
Clinicalapplications
FemaleAndrogenism
DHTisthebestmarkerforfemaleandrogenism,complementarymarkertotestosterone.IncreasedDHTlevelsarefoundinabout40%ofpatientswithidiopathichirsutismand35%ofpatientswithpolycysticovariansyndrome.WomenwithtoomuchDHTmaydevelopincreasedbody,facialandpubichairgrowth,amenorrhoeaandincreasedacne.AbnormalchangestothegenitaliamayalsooccurinwomenwithtoomuchDHT.
MalePatternBaldness(MPB)
DHTistheprimarycontributingfactorinmalepatternbaldness(MPB)orAndrogenicalopecia.MenwithMPBtypicallyhavehigherlevelsofDHT,lowerlevelsoftotaltestosteroneandhigherlevelsoffreetestosterone.ThetargetinterventiononthepatientsthatsufferfrombaldnessistopreventDHTfromactingonscalpandrogenreceptors.
BenignProstaticHyperplasia(BPH)
DHTplaysaroleinthedevelopmentandexacerbationofbenignprostatichyperplasia,aswellasprostatecancer,byenlargingtheprostategland.Prostategrowthanddifferentiationarehighlydependentonsexsteroidhormones,particularlyDHT.
5α–Reductase(5–AR)deficiency
Patientspresentingwith46XYkaryotypeandfemaleorambiguousgenitaliamaylacktheenzymetestosterone5α–reductase.Thisgenelesioncanresultinpseudohermaphroditism.Thisconditiontypicallypresentswithunderdevelopedmalegenitaliaandprostate.Theseindividualsareoftenraisedasgirlsduetotheirlackofconspicuousmalegenitalia.Intheonsetofpuberty,althoughtheirDHTlevelsremainverylow,theirtestosteronelevelselevatenormally.Theirmusculaturedevelopslikethatofothermaleadults.Afterpuberty,menwiththisconditionhavealargedeficiencyofpubicandbodyhair,andnoincidenceofmalepatternbaldness.
5α–reductasedeficiencycanbediagnosedafterpubertybymeasurementoftestosteroneandDHTconcentrations.
ExcerptfromtheInstructionsforUseEnzymeimmunoassayforthein-vitro-diagnosticquantitativedeterminationof5alpha-Dihydrotestosteroneinhumanserum.
5a-dihydrotestosterone(DHT)isasteroidsimilartotestosteroneandandrostenedione,whichbelongtoaclasscalledandrogens.DHTisaC19steroidandpossessesandrogenicactivity.ThebulkofandrogenproductiontakesplacemainlyintheLeydigcellsofthetestes.Androgenscirculateinthebloodboundtoproteins,especiallysexhormonebindingglobulin(SHBG)andalbumin.Atraceamountofthesesteroidscirculateintheunboundforminthebloodandarereferredtoasthefreefractions.DHThasatleastthreetimesthebindingaffinityforSHBGthantestosterone.Inmalesabout70%ofDHTisderivedfromperipheralconversionoftestosterone,whileinfemalesmostoftheDHTisderivedfromandrostenedione.Themajororgantoneutralizeandrogensistheliver.Thereforeintheliverthesteroidhormonesundergostructuralmodificationsthataregenerallyregardedasprerequisitesfortheirbiologicalinactivation.Somemetabolitesareformedandsomearereturnedtothecirculationbeforerenalexcretion.Therefore,eliminationofsteroidsfromthebodyisdonethroughtheurine.
ClinicalTrends:
InKlinefelter"ssyndrometheDHTlevelismuchlowerthanthatfoundinnormalmen.Inidiopathichirsutismabout40%ofthepatientshaveanincreasedlevelofDHT.Inpolycysticovaries(PCO)about35%ofthepatientshaveanincreasedDHTlevel.TheDHTlevelinyoungpeopleismuchhigherthanthosefoundinnormalolderpeople,henceandrogenproductionincreasesatpubertywhichgivesrisetomasculinizingcharacteristics.IthasbeendemonstratedthatthehumantestesproduceDHT,whichappearstooriginateintheseminiferoustubules.ThereforeintubulardamagetheproductionofDHTisimpaired,whichcausesadecreaseinthelevelsofplasmaDHT(patientswithgerminalcellaplasiaandazoospermia).ThereisaverylowlevelofplasmaDHTinpatientswithanorchia.Ithasbeenreportedthatinsomeprostatecancer(especiallyinstageD)thedeterminationofDHTcouldbeusefulinpredictingtheresponsetoanti-androgentherapy.
