PleasecontactusdirectlyformorespecificinformationaboutourGastrinRIAlikemethodcomparisons,publicationsorexperiencesfromotherlaboratories.Wewillprovideyouwithallrequiredsupporttoensureasmoothcontinuationofyourservicestoyourpatients!ThisassaycanbeofferedasalternativetothediscontinuedSiemensGastrinRIA.

RadioimmunoassayforthequantitativedeterminationofGastrininhumanserum.

Gastrinandthevagalnervesarethemainregulatorsofgastricacidsecretion.Howeverother
factorsthangastrincontributetothegastricacidsecretion.Themainsiteforgastrinproductionistheantropyloricmucosaofthestomach.Afewgastrinproducingcellsmayalsobefoundintheduodenumandpancreas.
Gastrinoccursinmanydifferentformsinhumanserum.AnamidatedC-terminalisessentialfortheBIOLOGicalactivityofthegastrins.Progastriniscleavedfrompreprogastrin.Ithasbeenshownthatprogastrinispartiallysulphatedinthetyrosineresidues.Theprogastrinisenzymaticallycleavedtothemaincirculatingformsofbiologicallyactivegastrin:gastrin-34andgastrin-17,whichoccurinsulphatedannon-sulphatedforms.Smallamountofgastrin-52(alsonamedcomponent1),gastrin-14(mini-gastrin)andevensmallerfragmentshavebeendetectedinserum.

Gastrinisoneofthebeststudiedguthormones.Itoccursinthecirculationinseveraldifferent
forms,amongthosegastrin-34andgastrin-17,sulphatedandnon-sulphated.
Thedeterminationofgastrinisusefulinthediagnosisofgastrin-producingtumoursandofachyliawithorwithoutperniciousanemia.Inalltheseclinicalsituationstheserumgastrinconcentrationishigh.Treatmentwithpowerfulantisecretagoguesmaycauseariseintheserumgastrinconcentration,becauseofanimpairedacidfeedbackinhibitionofgastrinrelease.Measurementofserumgastrincanthusbeusedtomonitorthetreatmentwithantisecretagogues.
Normallevelofgastrininhumanserum:< 60 pmol/l (fasting level obtained with this procedure).
Meanvalue:25pmol/l±10pmol/l(1SD).
Range:11-54pmol/l.

Enzymeimmunoassayforthein-vitrodiagnosticquantitativedeterminationofhomovanillicacid(HVA)inhumanurine.Historically,colorimetricanalysisofHVAutilizedthereactionof1-nitroso-2-naphtholwithbiogenicamines,thenthemethodwasimprovedbysubstituting1-nitroso-2-naphthol-4-sulfonicacid.However,thecolorimetricmethodsarenotspecificforHVAduetoknowninterferencebymanycompounds.
Thinlayerchromatography(TLC)onsilicagelwasanotherapproachtodetermineHVA.Thismethodisslowandrequiresspecialequipment.Usingaflame-ionizationdetectorandelectron-capturedetection,agaschromatographic(GC)methodwasalsodeveloped,buthasnotbeenwidelyadaptedduetotherelativelypoorsensitivity.FurThermore,gaschromatography-massspectrometrywasalsousedforquantitatingofHVAinbothserumandurine.
Finallyhigh-performanceliquidchromatography(HPLC)methodsinvolvinginitialseparationofthebiogenicaminesbyanion-exchangechromatographyandfinalseparationbyreverse-phase(C18)chromatographyhavebecomemostcommon,andpreferredmethods.Thesemethodsarereasonablyrapid(althoughrequiressamplepretreatment),haveexcellentsensitivityandlittleinterferencefromotherendogenouscompoundsorexogenousdrugsandfoods.

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