This document summarizes experiments on the excretion of inulin, glucose, and xylose by normal and phlorinized dogs. Two methods were used to measure sugar levels in plasma and urine samples: the Folin method and Shaffer-Somogyi method. Experiments found that the rate of inulin excretion is directly proportional to plasma concentration. Intravenous inulin infusion did not affect clearance of other substances. Xylose clearance in normal dogs was lower than simultaneous inulin clearance but increased after phlorinization. Phlorizin administration did not change relative clearances of inulin and creatinine but increased glucose and xylose clearance.

1. Secretion of inulin by
the dog
- SWETHA R
1

2. Chemical methods of experimentation
 This paper reports on the observations on the excretion of the polysaccharide
inulin ,glucose and xylose by a normal and phlorinized dog.
 For this two methods have been used.
 Using Copper sulphate sodium tungstate filtrate – By folin sugar method.
 Iron filtrate – by Shaffer somogyi method.
 The folin method gives incomplete reduction with xylose but when plasma
and urine are handled alike one should obtain the same U/P ratio by Shaffer
somogyi method.
 Nevertheless, in experiments where both the methods were considered, the
Shaffer somogyi method gave values for xylose clearance averaging 5% less
than that by folins method, although inulin and glucose clearances by the two
methods were identical.
2

3. People involved
 Somogyi- Folin sugar method (1931)
 Steiner, Urban, West by Shaffer Somogyi method (1932)
 Shannon and Smith
 Richards, Westfall and Bott (1934)
 Proffesor Richards (1935)
3

4. What is Clearance?
 What is Clearance?
 The rate at which a particular chemical is removed from the plasma indicates kidney
efficiency. This rate of removal is called renal clearance.
 In case of inulin is called Glomerular filteration rate (GFR).
 In case of PAH(para amino hippuric acid) it is renal plasma flow (RPF).
Normal Clearance Values (ml/min)
Glucose 0 Completely reabsorbed
Inulin 125 Not reabsorbed and not secreted
PAH 625 Completely secreted
4

5. Concept of Excretion: 5

6. Animal considered
Normal female dogs weighing from 15-18 Kg were
considered for this experiment.
6

7. Experimental Procedure
 A 20% solution of inulin in 0.6% saline is prepared at 85 C was
administered either intravenously or subcutaneously or by both routes.
 Through subcutaneous way, plasma concentration higher than 100mg is
not considered when fairly large concentrations are given. For this reason
inulin is given intravenously in doses of 2-4g/ Kg or in doses from 1-2g/Kg
subcutaneously followed by a like amount intravenously.
 The rate of inulin secretion in the dog is directly proportional to the
plasma concentration between values 53 and 565 mg per cent.
7

8. 0
50
100
150
200
250
300
350
400
450
500
550
600
0 100 200 300 400 500 600
Urine
Plasma 53.5 86 143.5 230 380 565
Urine 32.8 53.3 92.2 139 237 350
The rate of inulin secretion in the dog is directly proportional to the plasma concentration
between values 53 and 565 mg per cent.
8

9. Data to show that the intravenous infusion of inulin has no effect on
the renal clearance of other substances.
 At the conclusion
of period3,
 1.5g/Kg of inulin
in 0.6%NaCl -slow
intravenous
infusion
 Five tenths gm
xylose with 20cc
water/Kg-
stomach
 0.2g creatinine/Kg
in water-
subcutaneously.
Period 4 started 60 minutes after the end of period 3
9

10. Comparison of xylose, inulin and creatinine clearance in
the normal dog.
 Xylose – Through
stomach tube
 Creatinine and
inulin – by
subcutaneous
injection
10

11. Graph of U/P ratio of inulin with
creatinine.
 This a data showing the simultaneous U/P ratio (and
therefore the clearances) of creatinine and inulin a normal
dog. This equality is maintained after phlorinization
 In the series of 42 comparisons in 8 dogs, the ratio of the
simultaneous creatinine and inulin clearances has a mean
value of 0.994 with a standard deviation of 0.034, and a
maximum variations of about +0.086 and – 0.064.
11

12. Graph of U/P ratio of inulin with xylose
 This is a observation of 24 from 6 dogs.This a
data showing the U/P ratio ( and therefore the
clearances) of a normal dog is less than the
simultaneous U/P ratio of inulin. The dotted line
represents a xylose/inulin ratio of 1.0 and the
solid line a ratio of 0.734, the mean of the
observations.
 The xylose clearance in the normal dog at
moderate to high urine flows(0.88cc/minute) is
less than the simultaneous inulin clearance, the
mean xylose /inulin ratio being 0.734, with a
standard deviation of 0.022
 Phlorizin raises the xylose clearance to within 10% of the inulin clearance.
12

13. After the administration of phlorizin
Following the
intravenous infusion of
about 100mg/kg

14. Results after administration of
phlorizin:
 The administration of phlorizin has no effect on the relative values of
simultaneous inulin and creatinine clearances
 Glucose ofcourse occurs in the urine after phlorizin, the clearance of this
substance being identical with that of creatinine.
 Upon prolonged exposure to aqueous solutions phlorizin hydrolyzes to
phloretin and glucose. This is the reason why glucose occurs in the blood
after phlorinization
 Phlorizin also rises the xylose clearance relative to that of inulin clearance
but does not come equal to it remaining about 10% below the latter.
 In folins method the xylose clearance after phlorizin remains 5% less of
that of inulin clearance
14

15. Before and after phlorinization 15

16. Final results
 Secretion of inulin does not occur at all after phlorizination.
 Xylose is actively reabsorbed in normal dog.
 The ability to secrete creatinine as in dogfish and man is absent in dogs
thus creatinine clearance equals that of inulin clearance.
 Phlorizin completely blocks reabsorption of glucose in the renal tubules.
 Simultaneous Xylose and sucrose clearance in normal dog and
simultaneous xylose and glucose clearance in phlorinized dog are equal.
16

17. References:
 Chasis,H.,N.Joliffe and H.W Smith.
 Folin, O.J.Biol.Chem
 Goldring, W.J.chem invest
 Joliffe, N.,J.A.Shannon and H.A.Smith
 Marshal, E.K,Jr and A.L.Grafflin
 Shaffer, P.A and M.somogyi
 Shannon, N.Jolliffe and H.W.Smith
 Somogyi,M.J.biol chem
17

18. 18