551 



Result: The diluted laevulose solution also passes com|)leteIj 

 through the glomerulus epithelium. 



It seemed iuteresiiiig to investigate whether laevulose could 

 influence the retention of glucose. 



In order to ascertain whether the circumstances, as regards the 

 manner in which we had formei'lj worked with glucose, had indeed 

 remained unaltered, several experiments were made wilh glucose alone. 



B. Glucose and a mixture of Glucose and Laevulose. 



Experiment 6. (July 18). 



Perfusion liquid in which there was 0,l"/o glucose. 



0,1 c.c. of solution, reduction 0,0975"/,,. 



01 c.c. urine of right kidney: 0.3 c.c. Iodine solution; reduction 0,()46'Vo- 



0,1 c.c. urine of left kidney: 0,31 c.c. Iodine solution; reduction 0.0475%. 



Retained by right kidney: 0,0975—0,045 = 0,0525%. 



Retained by left kidney : 0,0975—0,0475 = 0,050/o. 



Experiment 7 (July 18). 



The same perfusion liquid as in experiment 6. 



0,1 c.c. urine of right kidney: 0,26 c.c. Iodine solution; reduction 0,035%. 



0,1 c.c. urine of left kidney: 0,29 c.c. Iodine solution; reduction 0,04257n- 



Retained by righ' kidney : 0,0975—0,035 = 0,0625'J/o. 



Retained by left kidney: 0,0975—0,0425 = 0,0550%. 



Experiment 8 (July 20). 



Perfusion liquid contains 0,07% glucose. 



Reduction by 0,1 c.c. of solution passed t),065'V() 



0,1 c.c. urine of right kidney: 0,22 c.c. Iodine solution; reduction 0,025'7(|. 



0,1 c.c. urine of left kidney: 0,'22 c.c. Iodine solution; reduction 0,025*^/0. 



Retained by each kidney: 0,065—0,025 = 0,04%. 



Experiment 9 (Sept. 20). 



At the same time an experiment was made in which the perfusion liquid contained 

 0,2% glucose. 



Reduction 0,1 c.c. of this solution 0,22%. 

 Reduction by 0,1 c.c. urine of right kidney 0,095%. 

 Reduction by 0,1 c.c. urine of left kidney 0,1125%. 

 Retained by right kidney: 0,22-0,095 = 0,1250%. 

 Retained by left kidney: 0,22-0,1125 = 0,1075%. 



From these experimejits it follows that now, as formerly, a 

 quantity of glucose is retained, which is physiologically present in 

 the blood of the frog. A remarkable contrast thus exists between 

 the permeability of the kidney to glucose and to laevulose. 



With thin marked diference it appeared to be of importance to 

 ascertain whether laevulose was perhaps capable of altering the 

 permeability to glucose. 



