牲畜生殖内分泌学

ClinicalReproductiveEndocrinologyJackyChanClinicalReproductiveEndocrinologyReproductivehormonesAssaymethodsPhysiologyofreproductivehormonesinthefemaleClinicalaspectsofreproductiveendocrinologyGeneralcommentsReproductivehormonesDefinitionofhormonesChemicalclassesofreproductivehormonesHormonereceptorsInterconversionofsteroidsintargettissuesSynthesisandclearanceofhormonesDefinitionofhormonessynthesizedandsecretedbyductlessendocrineglandsminutequantitiesdirectlyintothebloodvascularsystemClassicendocrineglands:pituitary,thyroid,parathyroid,adrenal,pancreas,ovary,testis,placenta,pinealglandDefinitionofhormonesReproductionpituitary,pinealglands,gonads,placentaadrenalandthyroidglandsuterus,hypothalamusReproductiveendocrineExtrahypothalamiccentresHypothalamiccentresAnteriorpituritaryGnRHOvaryUterusPinealMelatoninEstrogens/progesteroneFSH/LHEstrogens/progesteronePGF2αEstrogensInhibinGonadotropin-releasinghormoneGonadotropichormoneSexsteroidhormonesChemicalclassesofreproductivehormonesPeptideandproteinhormonesReleasinghormones,InhibitoryhormonesHypophysealhormonesNeurohypophysealhormonesPlacentalgonadotropinsSubunitsSteroidhormonesProstaglandinsThehormonessecretedfromtheanteriorpituitaryPeptideandproteinhormonesReleasinghormones,(GnRH,TRH,CRH,PRH,GH-RH)PeptidehormonesproducedwithinthehypothalamusAdenohypophysisInhibitoryhormonesGrowthhormone(GIH)Prolactin(PIH)portalveinTSHInsulin,glucagonReleasinghormonesGonadotropin-releasinghormone(GnRH)pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2(MWofGnRH1,182)regulatethereleaseofFSHandLHhypothalamic-pituitary-ovarianaxisLHsendsthesamemessageandresultsinincreasedtestosteroneproductionbythetestisduetoLHeffectontheLeydigcellsofthetestis.

LHandFSHarereleasedintothesystemiccirculation,travelingtothetargetreproductiveorgans(testesandovary)wheresexsteroidhormonesarecontrolled.ReleasinghormonesThyrotropin-releasinghormone(TRH)pGlu-His-Pro-NH2(MWofTRH362)regulatethereleaseofTSH,GH,andprolactinPathwaysofthyroidhormonemetabolismReleasinghormonesCorticotropin-releasinghormone(CRH)CRHisa41-aminoacidpeptideregulatethereleaseofACTHPeptideandproteinhormonesHypophysealhormonesGlycoprotein,FSHandLH,prolactinMWofLH30,000(bovine,ovine,procine,equine)MWofFSH32,000(ovine,equine)MWofprolactin23,000(bovine,ovine,procine)FSH,LH,TSH,ACTH–producedinbasophiliccellsProlactin–localizedinacidophiliccellsProlactinLuteotrophichormone

(LTH):acorpusluteum-stimulatingeffectinmouse,rat,dogandcat198a.a,MW23,300anda15-minutehalf-lifeinsheepincreasinginlactation(mamotropin)stimulatingthepigeoncropglandtosecret“cropmilk”PeptideandproteinhormonesNeurohypophysealhormones

Oxytocin,Vasopressin(synthesizedinhypothalamus)PosteriorpituitaryreleaseAxoplasmicfluidStimulationoftheNcellPeptideandproteinhormonesPlacentalgonadotropinsPMSG(eCG,MW70,000),aproteinhormoneinserum,producedbyfetaltrophoblasticcellsofpregnantmaresThefunctionofendometrialcupsbeginsonday36until120daysofpregnancy.hCG(MW36,000),aproteinhormone,extractedfromtheurineofpregnantwomenfrom30-40daysofpregnancyglucocortocoid,estrogen,progestin,relaxin…EndometrialcupsEndometrialcupsdevelopfromcellsofthechorionicgirdle,circumferentiallyaroundtheconceptusatapointwherethemembranesoftheallantoisandyolksacmeet.

270days1.TherelationshipofeCGandCLduringequinepregnancy2.eCGhasbothFSH-likeandLH-likeactivity,itprovidesthestimulusfortheformationofaccessoryCLsandmaintainaplateauofplasmaprogesteronefromabout50-140days.

OneStephCGUrinePregnancyTest

hCGisalsousedtotreatwomenwithcertainovariandisorders.ClinicaluseofhCG

AthletesusehCGtoincreasethebodynaturalproductionoftestosteronewhichisoftendepressedbylongtermsteroiduse.HCGtherapyhasbeenfoundtobeveryeffectiveinthepreventionoftesticularatrophyandtousethebodyownbiochemicalstimulatingmechanismstoincreaseplasmatestosteronelevelduringtraining.ClinicaluseofhCG

PeptideandproteinhormoneshCGLHhCG-subunitα:96a.asubunitβ:N-terminalspecificforhCGLH-subunitα:96a.asubunitβ:119a.aspecificforLHFSH-subunitα:96a.asubunitβ:specificforFSHTSH-subunitα:89a.ainhumansubunitβ:112a.ainhumanPeptideandproteinhormonesSubunits,,-subunit,uniqueforeachhormonewithinaspecies,determinesthebiologicalactivity.ChemicalclassesofreproductivehormonesSteroidhormonesderivedfromtheprecursor,cholesterolMW<500Estrogens(estradiol)Androgens(testosterone)Progesterones(progesterone)cholesterolC27H46OC21H30O2

C19H28O2

C18H24O2

ChemicalclassesofreproductivehormonesProstaglandinsagroupof20-CunsaturatedfattyacidsMW:300-400localhormones,shortbiologicalhalf-lifewithalocalactionfoundinmammaliantissues,uterusandprostataBiosynthesisofPGfromarachidonicacidperoxidaseSynthesisofprostaglandinaffectedbyestrogen

PhospholipidsArachidonicacidProstaglandinH2PGEPGFPGDInactivatedPhospholipaseA2Estrogen↑oxytocinreceptors↑Progesterone↓ProstaglandinH2synthetaseEstrogen↑Progesterone↓:1.proestrus→estrus2.priortoparturitionActivatedPhospholipaseA2PGE2stimulatesvasculardilation

bronchiodilation

gastrointestinalanduterinecontraction

inflammatoryresponsemimicshormonesthatactthroughcyclicAMPinhibitsplateletaggregationPGF2

stimulatesvascularconstriction

bronchioconstriction

smoothmusclecontraction,estinaltract,uterus

PGI2inhibitsplateletaggregation(increasescAMP)

vascularconstriction

bronchioconstriction

gastrointestinalanduterinecontractionFunctionofprostaglandins

vascularuteroovarianpathwaysforPGF2αUterinebranchofOVOvarianbranchofOVvascularuteroovarianpathwaysforPGF2αSystemicuteroovarianpathway:Localuteroovarianpathway:Combinedsystemicandlocaluteroovarianpathway:horse,rabbitsheep,cattle,(guineapig,hamsters,swinerats)?ClinicaluseofPGF2endometritis/pyometraClinicaluseofPGF2inductionofestrusOnsetofestrusOvulationprogesteroneCorpusluteum/NormalestruscycleOnsetofestrusOvulationShortenestruscyclewithPGF2PGF2

injectionforinductionofestrusOnsetofestrusOvulationClinicaluseofPGF2inductionofabortion/parturitionClinicaluseofPGF2inductionofabortion/parturitionClinicaluseofPGF2inductionofabortion/parturitionClinicaluseofPGF2misallianceinductionofabortionendometritis/pyometraonlyinthecaseofopenpyometra!!HormonereceptorsSteroidhormonesfatsoluble,abletoenterallcellslowconcentration(estrogen:10-150pmol/Linnon-pregnantfemale)Receptorsenablethetargetcells

-toconcentratethehormonewithinthecell-toelicitparticularcellularresponses-tocreateabiologicalresponseonspecificbindingThesteroidhormonereceptorismadeupofthreedomains:amodulatingN-terminaldomain(transcription-activationdomain),aDNA-bindingdomainaC-terminalsteroid-bindingdomain.

HormonereceptorspassivediffusionTargetcellsreceptorsnon-protein-boundhormoneprotein-boundsteroidhormonesteroid-receptorcomplexRNAsynthesis↑proteinsynthesis↑TranslocationofcomplexintonucleusE2:mammaryglandP4:endometriumT:sertolicellHormonereceptorsTargetcellsreceptorsactionsofFSHandLHingonadsProteinhormoneprotein-receptorcomplexcyclicAMPproteinkinaseactionsofcholesterolGproteinTissuesresponsivetoandrogensInterconversionofsteroidsintargettissuestestosterone5α-reductase5α-dihydrotesterone(5α-DHT)TargetcellsProgesteroneconversionintheplacentaCholesterolPregnenoloneProgesterone17α-HydroxyprogesteroneAndrostenedioneEstrone17α-HydroxylaseCortisolTestosteroneEstradiol17βPGF2α↑parturitionSynthesisandclearanceofhormonesSynthesisandclearancearemainthefactors,whichinfluencethehormoneconcentrations.Theconcentrationofahormonereflectsitsrateofsynthesisorsecretion.metabolizedbyliverdetectionofthebodyfluids(plasma,urine,saliva,feces…)reproductivecondition,exwildanimalsSynthesisandclearanceofhormonesunderthecontrolofgonadotropinsinpulsatilemode♂Thesecretionoftestosterone

changesinpulsatilerate.varyingfrom3.5–20nmol/Lwithinhours♀ThepulserateofE2andP4

remainsstable.SynthesisandclearanceofhormonesPlacentagonadotropins(hCG,eCG)producedinhighconcentrationlongerhalf-lifethanthepituitarygonadotropinsFSH,LH≒10-30minuteshCG≒1.5dayseCG≒6daysequineLH>otherspeciesSynthesisandclearanceofhormonesPGF2α15-keto-13,14-dihydro-PGF2αHalflifeprimaryPGF2α<20seconds15-keto-13,14-dihydro-PGF2α≒8minutes25mgPGF2α,IMincows>90%excretedintheurineandfeces(2:1)over48hoursAssayMethodsQuantificationofspecifichormonesisnecessaryfortheendocrinologicalevents.Weight-gainchangechemicaldeterminationsforsteroidhormonesurineanalysisImmunoassaytechniqueAgAbAssayMethodsImmunoassayRadio-immunoassay(Bersonetal.,1959),Sen:10-9Enzymemultipledimmunoassaytechnique,Sen:10-6Fluoescineimmunoassay,Sen:

10-9EIA(Engvalletal.,1970s),Sen:10-12Chemiluminescenceimmunoassay,Sen10-15RadioimmunoassayBecauseoftheeasewithwhichiodineatomscanbeintroducedintotyrosineresiduesinaprotein,theradioactiveisotopes125Ior131Iareoftenusedastheradioactiveantigen.SandwichEIAcompetitiveEIAsemiquantitativeELISAtestThechemicalluminolisoxidisedbyH2O2,toproduceamoleculeinanexcitedstate.Whentheexcitedelectronsinthemoleculesfallbacktotheirgroundstates,lightisgivenout.LuminolExcitedState

GroundStateAssayMethodsImmunoassayRadio-immunoassay(Bersonetal.,1959),Sen:10-9CompetitiveproteinbindingEIA(Engvalletal.,1970s),Sen:10-12Chemiluminescenceimmunoassay,Sen10-15DiagnosticaidsTherapy-monitoringNorthernsemi-sphereSubtropicalTaiwanMonitoringtheseasonalestrusactivityofmarePhysiologyofreproductivehormonesinthefemaleEstrouscycleControlofthecorpusluteumEarlypregnancyPregnancyandparturitionEndocrinecontrolofcyclicalreproductiveactivityThedurationofestrus,timeofovulationanddurationofCLfunctionindomesticanimalsInfluenceofthelengthofdaylightontheovaryfunctioninmaresPhotoreceptorsintheeyesPinealHypothalamusAnteriorpituitaryOvariesincreasingdaylightdecreasingdaylightneurotransmissionportalsystembloodcirculationMelatoninMelatoninGnRHGnRHGonadotropineGonadotropineestrousbehaviorofmaresLargeamountsofequineLHarereleasedduringan8-to9-dayperiodwithovulationoccurringonthe3rdto5thday.

Controlofthecorpusluteum

8-9daysthecainternahasLHreceptorandproducestestosterone.granulosacellhasFSHreceptorwhichcausescelltotaketestosteronefromthecaandconvertittoestradiol.dominantfolliclehasLHreceptorsongranulosawhichcanrespondtoLHtodriveprogesteroneproduction.

Eachgranulosacellhasapproximately1500FSHreceptors

P4+feedbackLHOvariansteroidogenesisFSHcausesincreasedaromataseactivity,whichconvertstestosteronetoestradiolProductionRateofSexSteroidsinWomenatDifferentStagesoftheMenstrualCycle

DAILYPRODUCTIONRATESEXSTEROIDS*Early

Follicular

Preovulatory

MidlutealProgesterone(mg)142517Hydroxyprogesterone(mg)0.5

4

4

Dehydroepiandrosterone(mg)77

7

Androstenedione(mg)Testosterone(mg)144

171

126

Estrone(mg)50

350

250

Estradiol(mg)36380250cumuluscellsproducehyaluronicacidandproteinstocausecumulusexpansionincreasedbloodflowtofollicle(vascularpermeability↑)ovulationTriggersincreaseproteinandsteroidsynthesis,andcellulardifferentiationwithinfolliclePlasminogenisconvertedtoplasminbyplasminogenactivator(activecollagenase↑).Prostaglandinstimulatessmoothmuscletocontractandforcetherupturedfollicletoempty.

ovulationControlofthecorpusluteumCLisresponsiblefortheestrouscyclicity.UteruscontrolsthelifespanoftheCLinthecow,ewe,sowandmare.EstrogensinitiateuterustosynthesizesPGF2α.RegressionofCLisaccomplishedwithin48hrs.ControlofthecorpusluteumEstrogensendometrialoxytocinreceptorsinitiatethereleaseofPGF2α,whichcausesthereactionoflutealregression.Inruminants,releasingofPGF2αisinducedbyoxytocinsecretedbytheCL.Indogandcat,PGF2α

CL?ControlofthecorpusluteumLHstimulatesthesecretionofprogesteronefromsmalllutealcellswhilePGF2αinhibitssecretionofprogesteronefromlargelutealcellsandcausesdegenerationofthesecells.EarlypregnancyMaternalrecognitionmodificationofPGF2α

bytheluteotropicproductsfromtheconceptusanduterusTrophoblastproteins(cow,ewe,doe)Estrogens(sow,mare)intrauterinemobilityoftheembryo(mare)?(bitch,queen)antiluteolyticactionorluteotrophiceffecttoextendthelutealactivityEarlypregnancyTrophoblastproteins(cow,ewe,doe)

oTP-1secretedbetween10and21-24daysbTp-1secretedbetween16-19dayscTP-1secretedonDay17tobinduterineoxytocinreceptorstoblocktheuterinePGF2αsecretionTrophoblastproteinsOvinetrophoblastprotein(oTP-1,IFN-τ)MW18,000,producedonDay10inhibitingtheuterineoxytocinreceptorsinhibitingthesynthesisofPGF2αPGF2↓,PGE2↑TrophoblastproteinoxytocinreceptorEarlypregnancyConceptus-derivedestrogens(sow,mare)estroneandestradiol17-β

convertedfromprogesteroneonDay11,Day14-18rapidenlongationoftheblastocystreleasingofcalcium,specificproteinsalteringanendocrineofPGtoanexocrinePGmetabolizedtoinactivePGFMPGF2PGE2Thesecretionofestrogensbytheblastocyststimulatesthereleaseofcalcium,specificpolypeptidesandproteins.alteringthePGF2fromtheendocrinetoanexocrineintrauterinePGF2metabolisedtoinactivePGFMbyfetalmembranesThereisextensivemobilityoftheequineconceptuswithinthehornsanduterinebodybeforefixationoccursbetweendays16and18.??EndometrialProstaglandinSynthesisInhibitor,(EPSI)fromendometriumTimeofmaternalrecognitionofpregnancy

DayofDayofdefiniterecognitionattachmentMare14-1636-38Cow16-1718-22Sow1218Ewe12-1316Goat17Corpusluteum&PregnancyP4fromCL:cow,sow,goat,dogandcatP4fromCL+fetoplacentalunit:mare,sheep

Pregnancy1.Thesheepplacentaproducesenoughprogesteronebyday60-70.2.Lutealprogesteroneisrequiredthroughoutgestationincattleandgoatsbecausetheirplacentasecretemuchsmallerquantitiesofprogesterone.Fetal-PlacentalUnitDihydroepiandrosteroneParturitionwithin12hoursParturitionProgesteroneParturitionFetalhypothalamusFetalpituitaryACTHFetaladrenalAdrenalcorticosteroidsFeto-placentalestrogensCotyledons/myometriumReleaseofPGF2MyometrialcontractionsPosteriorpituitaryOxytocinFetalmaturationDecreaseinplacentalP4LuteolysisoftheCLofpregnancyDecreaseinserumP4IncreasedmyometrialexcitabilityAdrenalineRelaxationandsofteningofcervixpelvicligaments,perineumRelaxin?ExpulsionoffetusStimulatesvaginaandcervixAbdominalstrainingCortisolParturitionParturitionProstaglandinsaresolubleinfatandwater,ProstaglandinspassfromcelltocellActions:smoothmusclecontractionluteolysissofteningofcervicalcollagendevelopinggapjunctionsmovementofCa2+betweenthemyofibrilsPGF2α,PGE↑,PGI2↓Smoothmusclecellsmolecules(<1000daltons)thatcanpassincludecalciumions,cAMP,ATP,glutathione,andlargemoleculeslikeaminoacidsandsugarsetc.

SmoothmusclecontractionMuscleprotein:myosinandactinCalmodulinactivatesMLCkinaseCalcium-CalmodulinMLCkinaseinactivemyosinlightchaincontractionsactomyosincomplex

(M*-ATP)+A<---->(M*-ADP-A)+Pi(M*-ADP-A)<----->(M-A)+ADP

Smoothmusclecontraction1.Calciumionscomefromoutsideofthecell.2.Calciumionsbindtocalmodulin-MLCK

complexonmyosin.3.TheenzymecomplexbreaksupATPintoADPandtransfersthePidirectlytomyosin.4.ThisPitransferactivatesmyosin.5.Myosinformscross-bridgeswithactin.6.Whencalciumispumpedoutofthecell,thePigetsremovedfrommyosinbyphosphatase.7.Themyosinbecomesinactive,andthemusclerelaxes.Thetopviewshowsarelaxedsmoothmusclecell.

Notethefocaldensitiesandthenetworkofactinandmyosinfilaments.

Whencontracted,thefilamentsslidetogetherandpullthecelltoamoreroundedappearance.SmoothmusclecontractionCalmodulinisoneoftheprimaryreceptorsofintracellularcalcium.4Ca2+bindtocalmodulin.Ateachbindingsite,Cainteractswithoxygenatoms,mainlyglutamateandaspartaseside-chaincarboxylgroup.Calmodulinmediatesprocessessuchasinflammation,metabolism,apoptosis,musclecontraction,nervegrowth,immuneresponse….ParturitionActionsofestrogenscontractileproteinsynthesis↑receptorsofoxytocinandPGF2α

↑calmodulinsynthesis↑MLCkinaseactivity↑gapjunctions↑ParturitionActionsofprogesteronegapjunctions↓receptorsofoxytocinandPGF2α↓synthesisofoxytocinandPGF2α↓calmodulinbinding↑ParturitionActionsofoxytocindependentonprogesterone↓,estrogens↑

stimulationofreceptorsintheanteriorvaginaand

cervixoxytocinreleaseincreasingPGreleaseincreasingCa2+releaseClinicalaspectsofreproductiveendocrinologySteroidhormoneconcentrationsarelowerinanimalsthaninhuman.(estrogens<1/10)Progesteroneanalysisgivethemostusefulinformationonthereproductivestatus.Blood,milk,urine,salivaandfecesaresourcesforendocrineinformation.Cow:P4forearlydiagnosisofpregnancyNegativeforecast(98%)isbetterthanpositiveforecast(67-90%).P4forpostpartumovarianactivityEstronesulfatefordiagnosisofpregnancyfromDay120,96%accuracyrateBovinepregnancyspecificproteinBforearlydiagnosisofpregnancyonDay30ClinicalaspectsofreproductiveendocrinologyP4forpostpartumovarianactivityorearlydiagnosisofpregnancySamplingtimeFollicularcystOvariancystP4forpostpartumovarianactivityP4forpostpartumovarianactivityLutealcystNormalcycleSampl