Intrarenal redistribution of blood flow after splanchnicotomy in the dog

LIFE SCIENCES Printed

in

Great

Vol. 6~ pp. 2573-2575~ 1967. Pergamon Press Ltd. Britain.

INTRARENAL

OF

REDISTRIBUTION SPLANCHNICOTOMY

FLOW

BLOOD

IN T H E

AFTER

DOG

L. "~ak~cs a n d P. Bencs~%h Second

meparlznent of Medicine, Budapest,

(Received

5 August

Regardln E the p h e n o m e n o n

1967;

University Medical

School

Hungary

in f i n a l

form

17 O c t o b e r

1967)

"denervation polyurla" the following explanations

h a v e b e e n suggested: I. may

Increased excretion of water a n d sodium by the denervated

result from the elevated renal blood flow ( R B F )

rate ( G F R ) If. T h e

kidney

a n d glomerular filtration

(see 1,2); effect is independent of increased lqBl~ a n d G F R ,

tion w o u l d diminish tubular reabsorption of sodium

i.e. denerva-

( 3 - 5 ). This v i e w w a s

supported by the fact that the denervated kidney with d e c r e a s e d ted more w ~ t e r a n d sodium than the innervated one

(6). It w a s

monstrated that the difference in electrolyte excretion b e t w e e n a n d innervated kidneys disappears

during massive

GFR

also de-

denervated

osmotic diuresis, a n d this

d o e s not appear causally related to a n y alteration in ratios for G F R renal plasma flow (7). Recent}y Lindheimer

et al. (8)

showed

little effect on sodium excretion of a n acute increase in G F R , ceUul~r v o l u m e

excre-

and

in the dog unless exira-

expanded.

In our present studies the intrarenal distribution of blood flow after unilatera/ splanchnic ner%~ dissection w a s

investigated.

Methods The

experiments w e r e

aesthetized with 30 m g / k g

carried out on mongrel dogs of both sexes anb o d y weight sodium pentobarbltal intravenously.

Left or right major splanchnlc nerve

dissection (renal "denervation")

2573

w~s

2574

Vol.

SPLANCI~ICOTOMY

performed s e v e n

days

earlier. A n i m a l s

contrds. Urine s a m p l e s w e r e (: ml/min :) a n d measured

6~

No.

25

without splanchnicotomy served a s

collected with ureteral catheters. Urine flow

urinary e x c r e U o n

o n both sides. T h e

of s o d i u m

(: U . V N a ; m i c r o E q / m i n : )

86Rb--accumulation

(9) w a s

method

were

used

to

estimate the blood flow rates for rena/ cortex, a s well a s for outer a n d inner medulla. The v a l u e s obtained w e r e Results a n d In the g r o u p of splanchnicotomized per cent differences b e t w e e n

calculated for i00 g tissue weight.

discussion animals the results are given a s

dener-v~ted a n d

intact kidneys. T o

matic error in the control group, in five out of ten d o g s

avoid syste-

left-right, while in

the other five animals right-left kidney per cent differences w e r e e x p r e s s e d (Table

I). I.

TABLE

BLOOD

CORTEX

CONTROL GROUP

FLOW

URINE

OUTER INNER MEDULLA MEDULLA

3,6 +- 9 , 3

0,9 +6,0

+O,7 4 ,0

FLOW

1,2 +15,4

URINARY EXCt~ETION OF SODIUM

0 4 +18,4

(n=lO) DENERVATED GROUP

14,6 + 16,5 +

49,3 + 5 2 , 9 ++

_

_

72,1 + 6 5 , 6 ++

208,6 -+ 3 7 7 , 8 + +

295 5 -+ 4 3 9 ,'2 +

(n=12) n = n u m b e r of a n i m a l s Values are mean per No

The

sign: + : ++ :

cent

differences

+ S.D.

(see

text)

p> 0,06 pC[ 0 , 0 5 p~--.O,Ol

r e s u l t s w e r e a s follows; I. In the control group no significant differences could b e o b s e r v e d

between

the two kidneys.

Vol.

No.

6,

25

SPLANCHNICOTOMY

II. Unilateral

splanchnicotomy

resulted flow and

a.

in a n

increased

b.

renal

cortical

urine blood

sodium

2575

excretion

rate

f l o w d i f f e r e d f r o m t h a t of t h e i n t a c t o n e

only

moderately, while medullary flow, especially in the inner medulla w a s markedly higher. Our data suggest that changes in the intrarened distribution of blood flow, in favour of medullary flow, n ~ y have a role in the mechanism of denerva[Jon polyuria. "I~his redistribution m a y affect the cortlco-medullary sodium gradient and thus alter the counter-current mechanism of concentration, but a shift in filtration fowB/'ds nephrons of lesser reabsorptive capacity (5) cannot be excluded, either. Reference s

i.

Wesson,~.G.Jr., W~dicine ( B ~ o r e )

2.

Kamm,D.D.,

3.

Kaplan,S.A., c . m . W e s t and S.3.Fomon, Amer.J.physiol.

175,363

36,281 (1057)

N . G . L e v i n s k y , J.Clin.Irrvest. 4 4 , 9 3 (1965)

(1953)

4.

Sartorius,A.W.,H.Surlington, Arner.J.Physiol. 185, 407 (1956)

5.

Blake, W . D . , Amer.J.Physiol. 202, 777 (1962)

6.

Fischer, A.,L.'l~kAcs, S.Varga, Ztschr.f.exp. M e d . 129, 33 (1957)

7.

Lindheimer, M. D., R. C. Lalone and B. Cr. Levinsky, J. Clin.Invest. ~ , 256 (1967)

8.

H a r t , W . M . and w . m . Blake, Fed.Proc. 26, 548/1631 (1967)

9.

HArsing, L., IxE.PeUey, PflLigers Arch.ses.Physi(M-. 285,302 (1965)