1922.] “ Renal Portal’? System. 175 
The Nitrogen Strengths 
of 8; and O tae in each case 0:000313 gm., both being therefore 
exactly equal 
EXPERIMENT 6.—Identical with the last save that the heart was 
cut out. 
Shut { IL+IR = 0:15 c.c. (25 m.) [N.E ] Aorta perfused at 
IIL+ITR = 1-0 c.e. (60 m.) [l ec. = 8)] = rates of 323 
c.c. per 
30 minu Ss. 
ig nae { ITIL +IITR = ? (15 m.) [N.E.] Aorta perfused at 
P IVL+IVR = 0°8 c.c. (90 m.) [l ec. =O} the rate of 406 c.c 
minutes 
on Cie re .) [N.E.] = ates 
: VIL+VIR = 0:7 (90 m.) [1 c.c. = 8] recorded. 
Chloride Sirenaeh 
T took exactly equal amie of S|, O and 8, and found that 
their ee strengths were respectively in the ratios of 6'1, 
71 and 7°5 
One possible defect in all i b wiiesitar experiments is the fact that 
while the renal afferent veins are open they are filled with fluid which 
comes from the legs, but when aay are closed they Sieh filled with 
a ‘ 
a 
seisecanie ® considerable excess in the nitrogen contents of the pa in 
0 way affects the nitrogen si bow th of the urine, this ‘¢ defect” c n be 
but of little or no consequence 
Another and perhaps more ‘serious defect is that on the closure of the 
two renal afferent veins, all the blood item! — the legs must i escape 

via the anterior abdominal veinalone. Sin channel 
resistance than three channels, thee tik means S that less fluid wi ill 2 r the 
legs by the iliac arteries in a given time, that the fluid domes in the 
aorta will thereby be raised and that therefore urine excr under such 
increased pressure will be hie" in nitrogen (and stronger in chloride) 
than that ogi when the two renal afferent veins are open (Appendix 
rt I o obviate any pobalbsitiy of this defect being of — 
ance I anidea te in ihe remaining experiments now to be described to inse 
canals into both renal afferent veins, cutting both of these behind the 
cann 
EXPERIMENT sho fStosohens cannula had an outflow of 74 c.c. per cpored 
at 24¢ and the two cannulae for the r.a.v. had pra 
sally tee equal abhor of ll c.c. per minute at 24 cms. pressure 
Aortic fluid consisted of 0°6% saline (tap water), 40 c.c. human 
urine being added to each 2,000 c.c., and was perfused at 25 cms. 
pressure; r.a.v. fluid was similar save that 61 c.c. human 
—_— _ do gate! Two r.a.v. bottles at 6 cms. pressure. Heart 
d two r.av. cut ind cannulae. The experime 
cited with the two r.a.v. shut (i.e. the tubing was a 
= j IL+IR = 2-0 c.c. (30 m.) flee. = SN] 
Bbut | TIL+IIR = 2-5c.c. (45 m.) [1 ¢.c. =o 1 the the rate of 301 c-c. 
per 30 minutes. 
Open § HUIL +IIR=0'4 c.c. (15 m.)[1 ¢ e.= ON]) Flows sing as 4) 
PeP LIVL+IVR = 1 2c.c. (119m.) [lc.c. =O]| :1, the aorta per- 
using at sg rates 
of 37 nd 
366 c.c. ner 30 
minutes. 
