The Effect of High Salt Intake on NaKATPase Activity of Tissues in the Rat_Clin Exp Hyperten 1994

8/11/2019 The Effect of High Salt Intake on NaKATPase Activity of Tissues in the Rat_Clin Exp Hyperten 1994

1/14

CLIN. AND EXPER. HYPERTENSION,

16 3),

327-340 1994)

THE EFFECT OF HI GH SALT I NTAKE

ON

NA, K+- ATPASE ACTI VI TY OF TI SSUES I N THE RAT

Paul Wai Chi ng Li , C S Ho and R Swamnat han*

Depart ment of Chemcal Pat hol ogy

Pr i nce

of

Wal es, Hospi t al

Shat i n, NT, Hong

Kong

and

UMDS, Guy s Hospi t al

St Thomas Str eet

LONDON

*Depart ment

of

Cl i ni cal Bi ochemst ry

Key Wor ds

:

Sodi um Na, K+- ATPase, sodi umt ranspor t

i nhi bi t or

ABSTRACT

1. The ef f ect of chroni c f eedi ng

of

hi gh sal t di et

on Na, K+- ATPase act i vi t y of hear t , l i ver ,

skel et al muscl e, ki dney and aor t a was st udi ed i n

t he r at .

2. Gr oups of r at s were ei t her gi ven t ap wat er or 18

g/ L sal i ne t o dr i nk. Af t er

7

days, mont hs

or

12 mont hs, t he cont rol group and sal t l oaded

~

* Present address and cor respondence t o:

Prof essor R Swamnat han

Depar t ment of Cl i ni cal Bi ochemst ry

Guy s Hospi t al

St Thomas Str eet

LONDON SE 9RT

Fax: 071 955

478

327

Copyright

1994 by

Marcel

Dekker, Inc

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DIETARY SODIUM AND Na+, K+-ATPase ACTIVITY

329

sodi umpump ( 6- 16) . Upregul at i on of sodi umt ranspor t

has been demonst rat ed i n several cel l t ypes 17-191,

i n

exper i ment al ani mal s ( 12- 16) and i n man

( 9- 11) .

The ef f ects of hi gh ci rcul at i ng l evel s of endogenous

sodi um t ranspor t i nhi bi t or on t i ssues ot her t han

ci rcul at i ng cel l s (20 ,211 i s not f ul l y document ed.

I n

ani mal model s, Na, K+- ATPase act i vi t y has been

repor t ed t o be i ncreased af t er hi gh sal t f eedi ng i n

t he renal t i ssue ( 22) , but not i n the hear t ( 23) .

I ncreased sodi um pump act i vi t y ( as measured by

rubi di um upt ake) i n vascul ar smoot h muscl e has been

shown af t er 4 weeks of hi gh sal t by Vasdev et a1 ( 24)

but not by Bradl augh et a1

25).

I n vi ew of t hese di screpant r esul t s, we examned

the ef f ect of chroni c f eedi ng of hi gh sal t di et on Na+,

K+

ATPase act i vi t y of di f f erent t i ssues i n the r at . ,

MATERI ALS AND METHODS

Adul t mal e Spr ague-Daw ey rats wei ghi ng about

250 g were used. The rat s had f ree access t o st andard

l aborat ory Pur i na rat chow ( composi t i on by wei ght :

prot ei n 23 f at 4. 5 mneral 2.5 , f i bre 6.0 and

ash

8 ) .

Unl ess ot herw se i ndi cat ed, t hey were

al l owed t o dr i nk tap wat er ad l i bi t um

Rat s were di vi ded randomy i nto t reat ment and

cont rol gr oups. Cont rol group was gi ven t ap wat er t o

dr i nk and exper i ment al groups was gi ven 18 g/ L sal i ne

t o dr i nk. Af t er 7 days ( n=12 i n each group)

,

3 mont hs

( n=14 i n each group) or 12 mont hs ( n= l i n each gr oup)

of t reat ment rat s were sacr i f i ced by cervi cal

di sl ocat i on and the hear t , l i ver , ki dney, skel et al

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330 LI, HO, AND SWAMINATHAN

muscl e ( hi nd- l i mb) and aor t a were qui ckl y exci sed and

kept i n col d hi st i di ne buf f er ( 33 mmol / L hi st i di ne,

2. 2

mmol / L EDTA, and

280

mmol / L sucr ose, pH 7. 2) . The

prot ocol f or the preparat i on of t i ssue homogenat e and

the assay met hods have been descr i bed i n detai l

el sewhere 16). Br i ef l y, the t i ssues were cut i nt o

f i ne pi eces and homogeni sed i n 10 vol of hi st i di ne

buf f er. The homogenat e was cent r i f uged and t he

supernat ant st ored at - 7OOC unt i l use.

Pr i or to assay, t he sampl es were treat ed w t h

sodi umdeoxychol at e ( DOC) i n or der t o sol ubi l i ze t he

membr anes 16)

Measurement

of

Na. K+- ATPase act i vi t v

To

reduce nonspeci f i c Mg++- ATPase act i vi t y,

homogenat es of hear t , l i ver , skel et al muscl e and renal

medul l a were prei ncubat ed w t h 5 mmol / L sodi um azi de

( f i nal concent rat i on) f or 30 mnutes at 37OC. The Na,

K+- ATPase act i vi t y of homogenat es of l i ver , hear t

,

skel etal muscl e and renal medul l a was det ermned by

t he coupl ed- enzyme assay. As the act i vi t y of vascul ar

Na, K+- ATPase act i vi t y i s l ow compared t o t he other

t i ssues K+- i mul at ed hydr ol ysi s of 3- 0-

met hyl f l uorescei n phosphat e ( 3- 0- MFP) ( 26) was used.

Al l measurement s were done i n dupl i cate.

Cowl ed enzvme act i vi t v

100

ul of t he enzyme preparat i on was pr ei ncubated

w t h and w t hout 100 ul of ouabai n sol ut i on ( f i nal

concent rat i on

5

mmol / L) f or

30

mnutes at 37OC. The

Na, K+- ATPase enzyme act i vi t y was measured by t he

decrease i n absorbence of NADH at

340

nm on a

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DIETARY SODIUM AND Na +, K+-ATPase ACTIVITY

33

1

cent r i f ugal anal yser ( Cobas Bi o, Hof f man La Roche,

Basl e, Sw t zer l and) as descri bed previ ousl y 16, 2 7 ) .

The Na+, K+- ATPase act i vi t y was cal cul at ed as the

di f f erence bet ween the ATPase act i vi t y i n the presence

and absence of

5

mmol / L ouabai n ( f i nal concent r at i on)

and was expressed at U/ mg pr otei n.

Pot assi um st i mul at ed 3- 0- MFPase assav

Homogenat e

of

aor t a was i ncubat ed w t h

20

mmol/l

of 3- 0- MFP i n Tr i s HC1. Hydrol ysi s of 3- 0- MFP bef or e

and af t er addi t i on of KC1 ( f i nal concent r at i on

10

mmol / L) was recorded. Based on t he sl opes

of

change

of f l uorescence, t he

K+

dependent phosphat ase act i vi t y

was cal cul at ed and expressed as umol of 3- 0- MFm n- mg- 1

prot ei n 16).

Protei n measurement

The prot ei n concent rat i on i n t he t i ssue

homogenat e was det ermned by the method of Lowry et a1

( 28) adapt ed to cent r i f ugal anal yser .

Resul t s are expressed as mean SEM The data

were subj ect ed t o two way anal ysi s of var i ance and

where t he nul l hypot hesi s was rej ect ed, Schef f e' s

compari sons were per f ormed; a p val ue ~ 0 0 5 was

consi dered si gni f i cant .

RESULTS

The ur i nary sodi umexcret i on i n the sal i ne gr oup

at 12 months was 27. 2 + 2. 4) mmo1/ 24 hour compared t o

1.6

+ 0. 1) mmo1/ 24 hour i n the cont rol gr oup. Fi gure

1 shows Na+, K+- ATPase act i vi t y i n t he var i ous t i ssues.

The Na, K+- ATPase act i vi t y of renal medul l a of t he

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332 LI, HO, AN D SWAMINATHAN

..

Z a

- 0 14

2 5

I

0 12

1

DAYS 3 MONTHS 12 MONTHS

SKELETAL

MUSCLE

0 06 7 1

LIVER

T

T

-

=

-

0 09

E

-:

me

0 08

a m

s

- 0 07

0 08

7

DAYS

3 MONTHS 12 MONTHS

KIDNEY

150 *+

.-

-

2 - 0 05 125

.c

d

= e

. 0 04

- E

= e

1 00

0 02 05 0

1 DAYS

3

MONT S

12 MONTHS

1 DAYS 3 MONTHS 12 MONTHS

1

DAYS 3

MONTHS

12

MONTHS

Fi gur e 1. Na, K+- ATPase act i vi t y of hear t , l i ver ,

skel et al muscl e, ki dney and aor t a i n sal t

l oaded ( hat ched col umns) and t hei r

r espect i ve cont r ol s ( sol i d col umns) .

Resul t s are mean & SEM.

*pcO.O5,

**p


7/14

DIETARY SODIUM

AND Nat

,

Kt

ATPase ACTIVITY

333

sal t - l oaded group was hi gher at

7

days,

3

mont hs and

12

mont hs compared t o t hei r r espect i ve cont rol groups.

Na, K+- ATPaseof hear t , l i ver and skel et al muscl e

of the sal t l oaded group was not di f f erent f rom

cont rol gr oup af t er

7

days of t reat ment . The hepat i c

enzyme act i vi t y af t er 3 mont hs and 12 mont hs was

si gni f i cant l y hi gher . Enzyme act i vi t y of al l t i ssues

af t er 12 mont hs of sal t l oadi ng was si gni f i cant l y

hi gher t han cor respondi ng cont rol group.

Sal t l oadi ng f or 7 days or 3 mont hs had no ef f ect

on aor t i c Na, K*- ATPase act i vi t i es measured as

3- 0-

MFPase act i vi t y. A si gni f i cant i ncrease i n 3- 0- MFPase

act i vi t y of aor t a was f ound when r at s were chr oni cal l y

f ed on hi gh sal t i ntake f or

12

mont hs.

DI SCUSSI ON

We have used t he 3- 0- methyl f l uorescei n

phosphatase assay f or the measurement of Na+/ K+- ATPase

i n t he aor t a, as t he vascul ar aor t a has a hi gh

pr opor t i on of Na+/ K+i ndependent ATPase act i vi t y 29-

30)

and methods whi ch depend on i nhi bi t i on by ouabai n

are not sensi t i ve enough. 3- 0- met hyl f l uor escei n

phosphat ase assay has been used by ot hers f or t he

measurement of Na+/ K+- ATPaseact i vi t y i n hear t muscl e

and skel et al muscl e and found to cor rel at e wel l w t h

ouabai n bi ndi ng si t es 31-33).

Our resul t s show that i n al l t i ssues examned Na,

K+- ATPase act i vi t y af t er 12 mont hs of sal t l oadi ng was

hi gher t han that of the cont rol group. I n t he renal

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334 LI, HO, AND SWAMINATHAN

medul l a, i ncreased act i vi t y of Na, K+- ATPase was seen

as ear l y as 7 days. Swann ( 23) f ound no di f f erence i n

the Na+, K+- ATPase act i vi t y

of

the heart i n r at s

recei vi ng hi gh sal t di et f or 4 weeks. I t was al so

repor t ed that sodi um ef f l ux f rom aor t a was not

di f f erent i n r at s gi ven hi gh sal t di et f or one mont h

( 25) .

There i s overwhel mng evi dence t hat hi gh sal t

i nt ake causes t he rel ease of an endogenous Na,

K+-

ATPase i nhi bi t or ( 1, 2, 34- 38) . The presence

of

endogenous i nhi bi t or i n the ci rcul at i on i s expected t o

cause a reduct i on i n the act i vi t y of t he enzyme at

l east i n the short t erm Al t hough t he l evel of

ci rcul at i ng i nhi bi t or was not measured i n t hi s st udy,

i n other st udi es we have shown presence

of

i ncreased

sodi um t ranspor t i nhi bi t or act i vi t y dur i ng sal t

l oadi ng ( 39) as have ot hers ( 34- 38) . Thus

i t

i s

surpr i si ng t hat the act i vi t y of t he Na, K+- ATPase was

not di f f erent at 7 days i n the sal t l oaded group. One

possi bl e expl anat i on f or the apparent l ack of

i nhi bi t i on coul d be due t o di ssoci at i on of t he

i nhi bi t or dur i ng the preparat i on of the t i ssue

homogenat e ( 23, 25, 40) Another possi bl e r eason f or

the apparent l ack of i nhi bi t i on coul d be that t he

l evel s of the ci rcul at i ng i nhi bi t or are t oo l ow t o

show

a

si gni f i cant ef f ect .

Na, K+- ATPase act i vi t y of al l t he t i ssues was

i ncr eased at one year . I ncrease i n Na,

K+

ATPase

of

hear t and ki dney i n rat s gi ven hi gh sal t di et f or

4

weeks has been document ed previ ousl y ( 22, 231.

As

far

as we are aware thi s

i s the f i rst repor t

on

t he ef f ect

of

sal t l oadi ng on Na, K+- ATPase act i vi t y of l i ver ,

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DIETARY SODIUM AND

Na+,

K+-ATPase ACTIVITY

335

skel et al muscl e and aor ta. The i ncreased act i vi t y of

t he enzyme i s probabl y due t o upregul at i on of t he

enzyme. We post ul at e that sal t l oadi ng r el eases a

sodi um t ranspor t i nhi bi t or and as a resul t of t he

ef f ect of t hi s subst ance, new Na, K+- ATPase uni t s are

synt hesi sed t o br i ng the i nt racel l ul ar sodi um and

number of act i ve uni t s t o normal . Dur i ng t he

preparat i on of the t i ssues f or t he measurement

of

enzyme act i vi t y the i nhi bi t or i s washed away and the

measured act i vi t y i s t heref ore hi gher . The r esul t s

observed coul d al so be due t o changes i n ot her f act or s

regul at i ng Na, K+- ATPase ( 3) . I t has al so been

suggest ed that t he upregul at i on of Na, K+- ATPase i s

secondar y t o i ncreased i nf l ux of sodi um i nduced by

sal t l oadi ng ( 1 9 , 2 5 ) .

The di f f erence i n the t i me requi red f or t hi s

upr egul at i on var i es f rom days t o 12 mont hs. Thi s

we suggest i s due to the di f f erence i n t he t ur nover

rat e of t he enzyme i n t hese t i ssues. Ti ssues w t h a

rapi d turnover t i me such as ki dney show an

upr egul at i on w t hi n 7 days whereas aor t a t akes one

year . We have previ ousl y shown si ml ar di f f er ence i n

t he rat e of upregul at i on of Na, K+- ATPase among

t i ssues i n rat s gi ven di goxi n

16).

As Na+ K+- ATPase i n di f f erent t i ssues have

di f f er ent subuni t s ( 41) , t he di f f erence i n t he t i me

requi red f or t he change seen here may al so be due t o

t he expressi on of di f f erent i sof orms.

We concl ude that l ong termsal t

l oadi ng causes an

i ncrease i n t he act i vi t y of Na+, K+ATPase of hear t ,

l i ver , muscl e and aor t a probabl y due

t o upregul at i on.

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336

LI,

HO, AND SWAMINATHAN

ACKNOWLEDGEMENTS

Thi s st udy was par t l y suppor t ed by a grant f rom

t he Croucher Foundat i on (HK) . We grat ef ul l y

acknow edge t he hel p of Mrs Carol i ne Morgan i n t ypi ng

t he

1.

2.

3.

4.

5.

6.

7.

8.

manuscr i pt .

REFERENCES

De Wardener HE, Cl arkson EM Concept s of

nat r i uret i c hormone. Physi ol Rev 1985; 65: 658-

759.

Got o A, Yamada K, I shi M, Sugi mot o T. Rel ease of

endogenous di gi t al i s- l i ke f act or w t h sodi um

l oadi ng.

Got o A, Yamada K, Yagi

N,

Yoshi oka M, Sugi mot o T.

Physi ol ogy and pharmacol ogy of endogenous

di gi t al i s- l i ke f act ors. Pharmacol Rev

N Eng J Med 1989; 320: 24- 5.

1992; 44: 377- 99.

De Wardener HE, MacGregor GA. Dahl ' s hypothesi s

that a sal uret i c subst ance may be responsi bl e f or

a sustai ned r i se i n ar t er i al bl ood pr essur e: i t s

possi bl e rol e i n essent i al hyper t ensi on. Ki dney

I nternat 1980; 18: 1- 9.

Bl aust ei n

MP.

Sodi um i ons, cal ci um i ons, bl ood

pressure r egul at i on and hyper t ensi on: a

reassessment and a hypothesi s. Am J Physi ol

1977; 232: C165- C173.

Bl uschke

V,

Bonn

R,

Greef f K. I ncrease i n t he

(Na + K+) - ATPase act i vi t y i n heart muscl e af t er

chroni c t reatment w t h di gi t oxi n or pot assi um

def i ci ent di et . Eur J Pharmacol 1976; 37: 189- 91.

Bonn

R,

Greef f

K.

The ef f ect of chroni c

admni st rat i on of (Na' K+) - ATPase i n gui nea-

pi gs. Arch I nt Pharmacodyn Ther 1978; 233: 53- 64.

Ford

AR

Aronson J K, Grahame- Smt h DG, Carver J G.

The acut e changes seen i n cardi ac gl ycosi de

recept or si t es ubi di um upt ake and i nt racel l ul ar

sodi um concent rat i ons i n the eryt hrocyt es of

pat i ent s dur i ng the ear l y phases of di goxi n

p

yp

y

y

g

g

Forpersonaluseonly.


11/14

DIETARY SODIUM AND

Na+,

K+-ATPase ACTIVITY

337

9.

10.

11.

12.

13.

14.

15.

16.

t her apy are not f ound dur i ng chroni c t her apy:

pharmacol ogi cal and t herapeut i c i mpl i cat i ons f or

chr oni c di goxi n t herapy. Br J Cl i n Pharmacol

1979;8:135-42.

Er dmann E Wer dan K, Kraw et z W I nf l uence of

di gi t al i s and di uret i cs on ouabai n bi ndi ng si t es

on human erythrocytes. Kl i n Wochensch

1984;59:1323-32:

Rapeport WG, Aronson J K, Gr ahame- Smt hDG, Car ver

J G.

I ncreased speci f i c 3H- ouabai n bi ndi ng t o

l ymphocyt es af t er i ncubat i on wi t h

acet yl st rophant hi di n f or days ( abst r act ) . Br

J Cl i n Pharmacol

1985;20:277-8P.

Cumberbat ch M, Zarei an K, Davi dson C, Morgan DB,

Swam nat han R. The ear l y and l at e ef f ect s

of

di goxi n t reat ment on t he sodi umt ranspor t , sodi um

cont ent and Na*, K+- ATPase of er ythr ocyte. Br

J

Cl i n Pharmacol 1981;11:565-570.

Whi t t aker J , Hawki ns

M,

Swam nathan R. Changes

i n eryt hrocyt e sodi um sodi um t ranspor t and 3H

ouabai n bi ndi ng capaci t y dur i ng di goxi n

adm ni st r at i on i n t he pi g. Li f e Sci

1983;32:747-

54.

Nechay BR, J ackson, RE, Zi egl er MG, Nel don SL,

Thompson J D. Ef f ects of chr oni c di gi t al i zat i on

on cardi ac and renal Na++K+- dependent adenosi ne

t r i phosphat ase act i vi t y and ci r cul at i ng

cat ecol am nes i n t he dog. Ci rc Res 1981;49: 655-

60.

Whi t t aker J , Swamnathan R. The ef f ect of

chr oni c di goxi n admni st r at i on on t he Na, K+-

ATPase act i vi t y i n t he pi g. I RCS Med Sci

1983;11:846.

Li ndsay R, Par ker J LW Rat hepat i c sodi um

pot assi umi on- dependent adenosi ne t r i phosphat ase

af t er t r eat ment w t h di goxi n and t hyroxi ne. Cl i n

Sci Mol Med

1976;50:329-332.

Wai Chi ng Li P, Ho CS, Swamnathan R. The

chr oni c ef f ect of l ong t erm di goxi n

adm ni st r at i on on Na, K+- ATPase i n r at t i ssues.

I nt J Cardi ol ( i n press)

p

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y

y

g

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Forpers

onaluseonly.


12/14

338 LI,

HO, AND SWAMINATHAN

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

Lamb J F, McCal l

D.

Ef f ect of prol onged ouabai n

t reatment of Na, K, C1 and Ca concent rat i on and

f l uxes i n cul t ured human cel l s.

J

Physi ol

( Lond) 1972; 225: 599- 617.

Boardman LJ , Lamb J F, McCal l

D.

Upt ake of 3H-

ouabai n and Na pump turnover rates i n cel l s

cul t ured i n ouabai n. J Physi ol ( Lond)

1972; 225: 619- 35.

Vaughan GL, Cook JS. Regenerat i on of cat i on-

t ranspor t capaci t y i n HeLa cel l membranes af t er

speci f i c bl ockade by ouabai n.

Proc Nat l Acad Sci

USA 1972; 69: 2627- 31.

Sai t o K, Furut a

Y,

Sano H, Oki shi o T, Fukuzaki H.

Abnormal rel at i onshi p bet ween di et ary sodi um

i nt ake and red cel l sodi um t ranspor t i n sal t -

sensi t i ve pat i ent s w t h essent i al hyper t ensi on.

Cl i n Exp Hyper t ensi on [A] 1985: 7; 1217- 32.

Dagher G, Brossard M, Feray J G, Garay RP.

Modul at i on of er t hyrocyte Na t ransport pat hway ( s )

by exceeeess Na i ntake. Li f e Sci 1985; 37: 243- 53.

Wal d H, Epst ei n FH, Popoot ze

MM.

Ef f ect

of

chroni c sal t l oadi ng on renal Na- K- ATPase

act i vi t y i n the r at . Proc Sco Exp Bi ol Med

1983; 172: 291- 6.

Swann AC. (Na, K+) ATPase regul at i on and NaCl

i nt ake: ef f ect s on ci rcul at i ng i nhi bi t or and

sensi t i vi t y to noradrenal i ne. Cl i n Sci

1985;69 : 441- 7.

Vasdev

S,

Prabakaren

VM

Fernandez P, Sampson C.

The rol e

of

vascul ar Na, K+- ATPase act i vi t y i n

sal t i nduced hyper t ensi on i n Dahl rat s. Res Comm

ChemPat hol Pharmacol 1988; 62: 79- 91.

Bradl augh

R,

Bi ng RF, Swal es J D, Thur st on H.

Ef f ects of changes i n di et ary sodi um i nt ake on

aor t i c sodi umpump act i vi t y i n the r at . Cl i n Sci

1987; 72: 143- 6.

Huang W Askar i

A .

Na, K+- ATPase: Fl uor i met r i c

det ermnat i on of the associ at ed K+- dependent 3- 0-

met hyl f l uorescei n phosphat e and i t s use f or t he

assay of enzyme sampl es w t h l ow act i vi t i es. Ann

Bi ochem 1975; 66: 267- 71.

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13/14

DIETARY SODIUM AND Na , K+-ATPase ACTIVITY

339

27.

28.

29.

30.

31.

32.

33.

34.

35

36.

Wong SY, Ho CS, Panesar NS, Swamnathan R. The

cont r i but i on of steroi ds to di goxi n- l i ke

i mmunoreact i vi t y i n cord bl ood.

Ann Cl i n Bi ochem

1992; 29: 337- 42.

Lowry 0 Rosebrough N, Far r A, Randal l

R.

Pr ot ei n measurement w t h the Fol i n- phenol

r eagent .

J

Bi ol Chem1951; 193: 265- 75.

Mnj i et S, Si m

K.

Decr eased Na+, K+- ATPase

act i vi t y i n the aor t i c endot hel i um and smoot h

muscl e of the spont aneous hyper t ensi ve rat .

Cl i n

Exp Hypert ens Theory Prac

1987:

A9 ( 4) ; 797- 812.

Wai Chi ng Li P. A st udy of the acut e and chroni c

ef f ect s of di goxi n and sal t - l oadi ng

on

Na+, K+-

ATPase act i vi t y i n t he rat .

M

Phi l Thesi s 1991

Chi nese Uni versi t y of Hong Kong.

Norgaard A, Kj el dsen K, Hansen 0. Na, K+- ATPase

act i vi t y of crude homogenat es of rat skel et al

muscl e as est i mat ed f romt hei r K+- dependent 3- 0-

met hyl f l uorescei n phosphat ase act i vi t y. Bi ochem

Bi ophys Act a 1984; 770: 203- 209.

Norgaard A, Kj el dsen K, Hansen

0.

K+ dependent

3- 0- met hyl f l uor esci n phosphat ase act i vi t y i n

cr ude homogenat e of rodent heart vent r i cl e:

ef f ect of K+ depl et i on and changes i n t hyroi d

st at us. Eur

J

Pharmacol 1985;

113:

373- 382.

Norgaard A, Baandrup U, Larsen

JS,

Kj el dsen K.

Hear t Na*, K+- ATPase act i vi t y i n cardi omyopat hi c

hamst ers as est i mat ed f romK- dependent 3- 0- MFPase

act i vi t y i n crude homogenat es.

J Mol l

Cel l

Cardi ol 1987; 19: 589- 594.

Wauqui er I, Devynck

MA.

Body f l ui d var i at i on and

endogenous di gi t al i s- l i ke compound dur i ng chroni c

NaCl l oadi ng. Cl i n Exp Hyper t ensi on 1989; 1217-

34.

Wauqui er

I ,

Pernol l et MG, Del va P, Lacour B,

Devynck MA. Hi gh sodi um di et and ci r cul at i ng

Hyper t ensi on 1986; 4: 463- 9.

di gi t al i s- l i ke component i n the r at .

J

Cast aneda- Hernandez

G,

Godrai nd T. Ef f ect

of

hi gh sodi um i ntake on t i ssue di st r i but i on of

endogenous di gi t al i s mat er i al i n the r at . Cl i n

Sci 1984; 66: 225- 8.

p

yp

y

y

g

g

Forpers

onaluseonly.


14/14

340

37.

38.

39.

40.

41.

LI, HO,

AND SWAMINATHAN

De Wardener HE, MacGregor GA, Cl arkson

EM,

Al aghbandzadeh

J ,

Bi t enski H, Cl yen J . Ef f ect

of

sodi um i ntake on abi l i t y

of

human pl asma t o

i nhi bi t renal Na*, K+- ATPase i nvi t ro. Lancet

igai;i:4ii-2.

Goni ck HE, Kramer HJ , Paul W Lu E. Ci r cul at i ng

i nhi bi t or of Na, K+- ATPaseaf t er expansi on of

ECF

vol ume i n rat s. Cl i n Sci Mol Med 1977;53:329-34.

Ho CS, Fung SLM, Swamnathan R. The ef f ect of

hi gh sal t di et on the excret i on of dopamne ( DA)

and sodi umt ransport i nhi bi t or STI) n the rat .

Cl i n Sci 1992;82: 16p.

Si er ra AD, Coca A, Agui l era MT, Urbano A.

Abnormal Na, K+- ATPase ki net i cs i n a subset

of

essent i al hyper tensi ve pat i ent s. Eur

J

Cl i n

I nvest 1988;18:337-42.

Li ngrel J B, Or l owski

J ,

Shul l

MM.

Pr i ce EM

Mol ecul ar genet i cs of Na, K+- ATPase. Prog Nucl

Aci d Res 1990;38:37-89.

Submitted: 5/04/93

Accepted: 10/22/93

p

yp

y

y

g

g

Forpers

onaluseonly.

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