1913.] Experiments on the Kidneys of the Frog. 



361 



Protocol I. — Pithed Male Frog. Cannulse in left aorta, origin of vena cava, 

 anterior abdominal vein and ureters. Hind legs tied off. Mesenteric 

 artery and right aorta ligatured and testes removed. 





Time. 



Fluid 

 escaping 



by 



v. cava. 



Urine. 



Concentration of 

 urine. 



Simultaneous arte- f 

 rial and venous J 

 perfusion oxyg. ] 

 Ringer's solution. [ 



3.15-3.30 

 3.30-3.45 



3.45-4.0 



c.c. 

 22 



27 

 21 



3.10-3.30 R. K. -1 c.c. 

 3.30-3.40{£f;02 , 



^-^{1:1:1% ;; 



-33 per cent. NaCl. 

 0-32 „ 

 -29 



-41 „ 

 -40 



3.58-4.4. Perfused ]/10,000 HgCl 2 through renal portal veins. Arterial perfusion main- 

 tained. Then perfused Ringer's solution for 5 minutes through renal portal veins, to wash 

 the mercuric chloride out of the vessels. 



Simultaneous per- 

 fusion, art. oxyg., 

 venous non-oxyg., 



but containing 

 "1 p. c. caffein. J- 

 A. press. 24 cm. 

 V. 12 cm. 

 Ringer = -53 

 per cent. NaCi 



4.0-4.30 

 4.30-5.0 



43 

 48 



a o a q^/R- K. 0-1 c.c. 



4 °- 4 - 30 |l.k.o-i „ 



-53 per cent. NaCl 



052 „ 



Finally perfused weak ammonium sulphide through renal portal vein. 

 Kidneys cut in serial section ; no mercury observed histologically in the glomeruli. 



The venous perfusion of corrosive sublimate causes considerable vaso- 

 constriction, and the efferent vessel from the glomerulus which ends in the 

 tubular capillary network appears to be particularly affected. This, at least, 

 is our interpretation of the extremely slow perfusion through the glomeruli 

 which is met with under these circumstances and which is associated with a 

 lessened flow of urine. We have attempted to overcome this vaso-constric- 

 tion by perfusing through the renal portal veins Einger's solution containing 

 a trace of acetic acid or OT per cent, caffein sodium benzoate, but without 

 complete success. We have obtained, however, a rate of perfusion through 

 the glomeruli which was adequate to maintain their vitality, and in some 

 experiments was for a time equivalent to that of the normal kidney, although 

 it eventually became very slow. The employment of 1/10,000 mercuric 

 cyanide caused less vaso-constriction, but also less definite histological 

 evidence of the complete poisoning of the tubules. The results of a number 

 of these experiments are shown in Table II. 



