Mechanisms of potassium permeation in the in vitro perfused cortical collecting duct of the rabbit

173 Pages·1992·3.9 MB·English

by  Zhou, Xiaoming

MPEECRHFAUNSIESDMSCOORFTPIOCTAALSCSOILULMEPCETRIMNEGADTUICONTIONFTTHHEEINRAVBIBTIRTO
By
XIAOMINGZHOU
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOLOF
THREEQUUNIIVREERMSEINTTYSOFFORFLTOHREIDDAEGINREPEAROTFIADLOFCUTLOFRIOLLFMPEHNITLOOSFOTPHHEY
UNIVERSITYOFFLORIDA
1992
ToXiaofang,Martin,myparents,andmybrother.
TABLEOFCONTENTS
ACKNOWLEGEMENTS v
LISTOFTABLES viii
LISTOFFIGURES x
KEYTOABBREVIATIONS xiii
ABSTRACT xv
CHAPTER1 INTRODUCTION 1
1.1 Background 1
11..32 PPoottaassssiiuummASebcsroertpitoinonbybythteheCoCrotritciaclalCoClollelcetcitnigngDuDcutct ... 140
1.4 TheAimsandObjectivesofthePresentStudies 13
CHAPTER2 GENERALMETHODOLOGY 23
2.1 InVitroMicroperfusion 23
22.32 FStlaatmiestliecsalsAAntaolmyiscesAbsorptionSpectrophotometry 2256
CHAPTER3 EFFECTOF10%C02ONRbEFFLUX 28
3.1 Introduction 28
3.2 MethodsandMaterials 30
3.3 Results 31
3.4 Discussion 38
3.5 Summary 48
CHAPTOENRR4bEEFFFFELCUTXOFBARIUM,AMD^ORIDEANDOUABAIN 70
4.1 Introduction 70
4.2 MethodsandMaterial 72
4.3 Results 72
4.4 Discussion 76
4.5 Summary 79
CHAPTER5 EFFECTSOFLUMINALSODIUMONRbEFFLUX . 88
5.1 Introduction 88
5.2 MethodsandMaterial 88
5.3 Results 89
55..45. DSiuscmumsasrioyn 9947
CHAPTCEARRB6ACEHFOFLECTOFANGIOTENSINII, HISTAMINE,AND Ill
6.1 Introduction Ill
6.2 MethodsandMaterial Ill
6.3 Results 112
6.4 Discussion 114
6.5 Summary 115
CHAPTUERRIN7EENFaFAENCTDOKFLNEaVEALNSDAKNDINUTRAIKNEEOONUTSPEURTUMA..N.D. 122
7.1 Introduction 122
7.2 MethodsandMaterial 122
7.3 Results 122
7.3 Discussion 123
CHAPTER8 SUMMARYANDCONCLUSIONS 127
REFERENCES 137
BIOGRAPHICALSKETCH 150
iv
ACKNOWLEDGEMENTS
IwishtoexpressmygratitudeandappreciationtoDr.CharlesS.Wingo,
the chairman ofmy supervisory committee, for his instrumental guidance,
productive encouragement,invaluablesupportandkind carethroughoutthe
fulfillmentofthiswork.Histremendouscontributiontomyscientificknowledge,
professionalcareer,mypersonalityandpersonallifearebeyondmyabilityto
acknowledge. I will benefit from his tradition of dedication, criticism,
responsibility,precisenessandcarefulnessinbothofmyacademicactivitiesand
privatelifeforaverylongtimetocome.IamindebtedtoDr.GeorgeA.
Gerencser,theco-chairofmycommitteeforhisvitalrole inmydoctoral
education.Histhoughtfulinstructionwasinvaluableduringthecourseofmy
studies.Hisunderstandingandfriendshiparegreatlyappreciated.
Iextendmysincerethankstothemembersofmysupervisorycommittee,
Drs.LaiC.Garg,BruceR.StevensandBrianD.Cainfortheirveryhelpful
suggestionsandcriticism.Theyhaveprovidedmewithalternativeinterpretations
andadditionalinsightthathaverequiredadditionalstudies.Iamgratefulto
ScottStraubandAmyWallfortheirexperttechnicalhelpwhenIwaslearning
invitromicroperfusion.ThepersonalfriendshipwithScottStraubandHarold
Snellenestablishedduringpastfouryearsiswarmlyappreciated.Isincerely
appreciateDr.FrancesArmitageandWeiUeberschaerfortheirimportantrole
inthisresearchandfortheirhelpwithmyEnglish.Thediscussionsofmy
researchresultswiththemandwithDrs.KevinCurranandMitchellHebert
havebeenproductiveandenjoyable.Iamalsogratefultothefacultymembers
intheDepartmentofPhysiology,especiallyDrs.M.IanPhillips,ColinSumners,
Sidney Cassin, Melvin Fregly and Charlie Wood for their advice and
encouragement.Inaddition,IwishtothankDrs.C.CraigTisher,Christopher
Wilcox,KirstenMadson,WilliamWelch,andIDavidWeinerintheDivision
ofNephrology,HypertensionandTransplatationfortheirconcernandadvice.
IwishtothankAnnCrawfordindepthforherexcellentandcourteoushelp
inpreparationofthisthesisaswellasothermanuscriptsandabstracts.Iam
alwaysgratefultohavethemanuscriptsbackfromAnnbeforeFridaysothat
Ihavesomethingtoworkwithduringtheweekend.Mysincerethanksshould
bepresentedtoRobertFlemingforhisconstantconcernandsupport.My
specialthanksshouldbeofferedtoJaniceDolsonnotonlyforherexperthelp
with my learning some special functions ofWordperfect, but also for her
friendlyunderstandingandsupportduringthepastthreeyears.Ialsoappreciate
Ms.GinnyYoungforhersecretarialassistancetoDr.Wingoregardingmy
education.MydeepthanksareextendedtoMiss.B.J.Streetman,VictoriaLa
Placa,PiaJacobsandGayleButtersandMr.KevinFortinfortheirnecessary
roleinmydoctoraleducation. Theconstantconcernandsupportfrommy
fellowstudentsintheDepartmentofPhysiology,especiallyHong-genChenand
Jian Kane, and Jenny Zhang in the Department of Pharmacology and
Therapeuticsarewarmlyappreciated.
IamgreatlyindebtedtomywifeXiaofang,myfatherQuibaoZhou,my
vi
motherSupingBuandmybrotherXiaolinfortheirlove,consideration,backing
andunderstanding.Xiaofanghasunselfishlydevotedherlifetothefamily.This
dissertationisespeciallydedicatedtoXiaofangandMartinatthisspecialtime,
althoughitisimpossibletoexpressmygratitudetothemadequatelyinwords.
ThebirthofMartininthefinalstageofmydoctoraleducationnotonly has
increasedmyexcitementforthepresentstudies,butalsohasinspiredmeto
aimathigherqualityofprofessionalandprivatelifeinorderformetocarry
out the honor, duty, desire, and role model as a father. Without the
fundamentalandinstrumentaleducationofmychildhoodbymyparents,it
would be unimaginableforme tobe able to choose the presentway of
pursuingmylife.
vii
LISTOFTABLES
Table3-1. Compositionofsolution 50
Table3-2. Effectofluminal0.1%DMSOonK^andVT 51
Table3-3. TimecontrolforK^,andVT 52
Table3-4. Effectof10%COaonVTinthepresencecolchicine . 53
Table3-5. Epfrfeetcrteatoefd1w0i%thC0O.,5*ioMnMVATPiTnAtMheatnubdulWe-s7 54
Table3-6. ECfCfeDctinofth1e0%preCs0en2ceonanKd^absaenndceVTofbylutmhienanlorBmaal.... 55
Table4-1. Compositionofsolutions 80
Table4-2. EafnfdectlumoifnaDlM1S.5OmiMnthNeaabsenceofluminalNa 81
Table4-3. EofnfeVctToifnltuhmeinaablse1n0c/eiMofSlCuHm2i8na0l80Naor0.1mMouabain 82
Table5-1. Compositionofsolution 99
Table5-2. EffectofremovalofluminalNaintheabsence
oafbsleunmcienaolfBlau,miananldNofaluminalBaadditioninthe 101
Table5-3. EffectofluminalBaadditioninthepresence
ofluminalNa,andofluminalNaremovalinthe
presenceofluminalBa 102
Table5-4. pEfrfeescetncoeforfem4ovmalMofBaluminalNainthe 103
Table5-5. bEfoftehct2omfMluBmainaalndNa10r|eimMovSaClH2o8f0i8n0thepresenceof 104
Table5-6. EffectofluminalSCH28080onVTintheabsenceand
viii
presenceofluminalNa 105
Table5-7. EffectofSCH28080inthepresenceof20mMK ... 106
Table6-1. Compositionofsolution 116
Table6-2. Elfufmeicntalof3hmisMtamBianeonVTinthepresenceof 117
Table6-3. Effectof0.1mMcarbachol 118
Table7-1. uErfifneec,tNofalaonwdNKaandlowKonexcretionof 125
Table7-2. EsfefreucmtoNfalaonwdNKalaenvdelslowKdiet,andlowKdieton 126
LISTOFFIGURES
Figure1-1. Distributionofpotassiuminthebody 16
Figure1-2. Segmentalanalysisoftubulepotassiumtransport .... 17
Figure1-3. Urinarypotassiumexcretionasafunctionof
plasmapotassiumconcentrationincontrolanimals
andinalkaloticandacidoticconditions 18
Figure1-4. Effectofdifferenttypesofacid-basedisturbances
onpotassiumsecretionbydistaltubule 19
Figure1-5. Thecellularmodelsoftheprincipalcellandthe
intercalatedcell 20
Figure1-6. Cellmodelofepithelialsodiumandpotassium
transport 21
Figure1-7. ThechemicalstructureofSCH28080 22
Figure2-1. Thecorticalcollectingductperfusedinvitro 27
Figure3-1. EofffeScCtH2of801800%CO,onICy,andVTintheabsence 56
Figure3-2. Thepredictedvoltage-mediatedincreaseinK^and
toobse1r0v%edCi0nc2reaseinK^,followingexposure 57
Figure3-3. EofffeScCtH2of801800%CO,onK^.andVTinthepresence 58
Figure3-4. EafnfdecVtTofin1t0h%eCab0s2enacnedo0f.1SCmHM280m8e0thazolamideonKr,, 59
Figure3-5. EafnfdecVtTofin1t0h%eCpr0es2eanncedo0f.1SmCHM28m0e8t0hazolamideonK^ 60
Figure3-6. 0E.f1fecmtMofmseitmhualztoalnaemoiudseexopnosKurr,,eatond1V0%TC02and 61