Acta Medica Scandinavica. Vol. LXXXIII, fasc. I-IV, 1934. From the Liverpool Heart Hospital, Liverpool. Salyrgan and Ammonium Chloride as Diuretics in Cardiac 0ederna.l I.. HARRIS, E. L. RUBINZ and J. S. LAWRENCE. Introduction. It is common knowledge that sodium chloride plays an impor- tant part in the aetiology of oedema. Recently it has been shown that an impaired renal function for salt excretion is a t least one of the causal factors of cardiac oedema. (1) Broadly the degree of oedema which the administration of a given quantity of water and salt will produce stands in inverse ratio to the renal capacity for salt excretion. In order to understand the relationship between salt and oedema it is necessary to keep in mind two facts in connection with the economy of sodium chloride in the animal organism. First: Blood chloride fluctuates in health and disease only within narrow limits. The osmotic pressure of the blood must be maintained on a certain level without which life would become impossible, and two thirds of the osmotic pressure is conditioned by the presence of salt in the blood. (2) Secondly: Even the normal kidney is only capable of excretion of a urine of a low sodium chloride concentration (about 2 per cent.). (3) In heart failure, which secondarily affects the water excretion of the kidney, the capacity of the latter for salt excretion is greatly lowered. It is clear that in cases in which the proper eli- mination of salt by the kidney is impossible the sodium chloride Submitted for publication February 27, 1934. * M. Stern and Mrs T. Temple Research Fellow.
Salyrgan and Ammonium Chloride as Diuretics in Cardiac 0ederna.l
I.. HARRIS, E. L. RUBINZ and J. S. LAWRENCE.
Introduction. I t is common knowledge that sodium chloride plays an impor-
tant part in the aetiology of oedema. Recently it has been shown that an impaired renal function for salt excretion is a t least one of the causal factors of cardiac oedema. (1)
Broadly the degree of oedema which the administration of a given quantity of water and salt will produce stands in inverse ratio to the renal capacity for salt excretion.
In order to understand the relationship between salt and oedema it is necessary to keep in mind two facts in connection with the economy of sodium chloride in the animal organism.
First: Blood chloride fluctuates in health and disease only within narrow limits. The osmotic pressure of the blood must be maintained on a certain level without which life would become impossible, and two thirds of the osmotic pressure is conditioned by the presence of salt in the blood. (2)
Secondly: Even the normal kidney is only capable of excretion of a urine of a low sodium chloride concentration (about 2 per cent.). (3) In heart failure, which secondarily affects the water excretion of the kidney, the capacity of the latter for salt excretion is greatly lowered. I t is clear that in cases in which the proper eli- mination of salt by the kidney is impossible the sodium chloride
Submitted for publication February 27, 1934. * M. Stern and Mrs T. Temple Research Fellow.
24 I . H A R R I S , E. L. R U B I N and J . 5. L A W R E N C E .
will have to accumulate in the tissues, since an unduly large amount of salt in the blood must interfere with the maintenance of the normal osmotic pressure so essential to the preservation of the organism. The exact mechanism by which it is brought about need not be discussed here. I t is only necessary to point out that the tissues, such as the fluid of oedema, frequently contain a much higher sodium chloride percentage than that of the blood. Where salt goes water will follow. As yet i t is impossible to appraise how far a lowered colloidal and increased hydrostatic pressure favours the formation of oedema. But i t is certain that impaired function
' for salt excretion is a very important factor in the aetiology of cardiac oedema. The problem therefore of the thereapy of oedema is partly the problem of how to improve the salt excretion of the kidney. The investigation has been undertaken with this object in view.
The effect of Salyrgan and ammonium chloride on the elimina- tion of salt, was studied.
Plan.
The following plan of investigation was adopted: The patient was placed under observation for 4 days. For
the next 4 days 20 g of sodium chloride and 120 ounces of water were given daily. After an interval, a further period of 4 days on salt and 120 ounces of water plus Salyrgan, or KC1 or acidifying diuretics daily. (Salyrgan was given only in the initial stage of this period.) In some instances different drugs were given in cases of oedema, without salt and water. Several cases were given more than one drug, with a suitable interval of time between each, so that the relative effects of these drugs on the same subject could be compared.
The drugs were given as follows unless otherwise stated: Salyrgan, 1 cma intramuscularly; Sodium Chloride, 20 g daily; Ammonium Chloride, 12 g daily. The cases were investigated from the following points of view: 1) The renal capacity for salt excretion, viz., daily urine output,
percentage of chloride in the urine, concentration and dilution test and blood chlorides.
S A L Y R G A N A N D A M M O N I U M C H L O R I D E I N C A R D I A C O E D E M A . 25
2) The blood condition as the result of the administration of various drugs. From the point of view of hydraemia, inaddition to blood chlorides, haemoglobin estimations were made, and refractometric readings taken.
3) From the point of view of the reaction of the blood, namely, pH of the whole blood.
Cases were generally allowed a rest of one or two days between each stage of the treatment. During the whole of the investiga- tion the cases were on ordinary hospital diet. Fluid intake and urine output were carefully measured over 24-hourly periods. Blood examinations were carried out on the last day of each 4-day period. When Salyrgan was given, the blood was examined in some cases 3 ‘/2 hours and in other cases 24 hours after the injection of the drug.
The Base in Blood Serum analysed separately.
The followiirg methods have been used: Serum Sodium Kramer & Gittleman, Journ. Rid. Chem. 1924,
Adaptation of Fiske’s with Hoffmann’s Modification. .lourn. Biol. Chem. 1931, 93. 787.
62, 354. Modified by Rourke, J. Biol. Chem. 1928, 78, 337.
Methods.
The pH of whole blood was determined with the glass electrode. Details of technique will be dealt with in a separate communication. ( I t will be published in the Journal of Physiologie).
Urine chloride was determined by Volhard’s titration. Blood chloride was determined by iodometric titration with
nitrite-starch indicator according to the method of McLean and Van Slyke.
H aemoglobin Percentage was determined by the Klett colori- meter, using the acid Haematin method with Newcomer’s Standard Plate.
26 I . H A R R I S , E. L. R U B I N and , J . S. L A W R E N C E .
The Refractioe Index of blood serum was taken by the Abbe refractomater.
Heiss (4) elaborated tables of Protein percentages based on these indices, but Neuhausen and Reoch (5) have shown that there is a factor of error in converting the refractive index of serum into protein percentages. For this reason the indices themselves are shown and are quite sufficient for purposes of comparison.
Weight. The patients were carefully weighed a t the same time each day, and wearing the same clothing.
Renal Efficiericrr Tests .- The Koranyi-Volhard method (6) is simple and in our opinion reliable. I t depends on the ability of the kidney to pass dilute or concentrated urine, and the degree of dilution or concentration is determined by the depression of the freezing point. This test was carried out in all cases.
Blood Chloride
Salyrgan. Table I.
(Fluid Intake = 120 02s.)
Comparing conditions under the administration of Sodium Chloride alone with those resulting from NaCl+Salyrgan.
Weight lost after
NaCl +
- -
2 3 4 5 ti 7 8
10 11 12 -
- NaCl + Sa- yrgan
Highest Urine
NaCl + Sa- - I lyrgan NaC1
(ounces)
Output
-
Salyrgan
Ibs. 02s.
130 72 78
120 140 56 80 91
100 110 -
517 544 565 555 - -
622 622 577
118 119 100 84
116 139 130 114 116 118
1 4
3 4
5 12 6 8 2 - 4 -
- -
4(gain
4 8
3ighest Conc. of Chlor. in
Urine
NaCl -
993 900 681 895 786 680 730 7 10 570 645
- NaCl + Sa- YrlW
830 495 595
1012 1070 745 860 790 630 680
-
-
NaCl - 630 611 578 577 592
615 626 626
.615
-
Total daily Chloride ou tpu t
in
NaCl
-
- 24.0 11.8 11.7 22.5 22.3
4.9 9.0
14.8 12.9 16.3 -
ams NaCl + Sa.
-
lyraan
26.5 7.4
14.0 25.8 28.0 25.7 26.2 22.5 16.0 19.0
Expressed as mg %-NaCI.
S A L Y R C A N A N D A M M O N I U M C H L O R I D E I N C A R D I A C O E D E M A . 27
Comparing conditions under the administration of sodium chloride alone with those resulting from NaCl + Salyrgan. Fluid intake = 120 oz. daily.
From this table i t will be seen that in most cases the highest urine output follows the administration of salyrgan. The table also demonstrates that a higher urine concentration of chloride is found after salyrgan in the majority of cases, and that the total chloride excretion is increased in every case but one. A definite fall in weight takes place in every case but one under the influence of salyrgan.
Case 2 is interesting in regard to the action of salyrgan on urinary and chloride output. This case showed the highest salt concentration of urine under observation, in this series. In this case the highest urine output under salt alone is greater than that under salt and salyrgan and the percentage of salt in the urine is actually lower under this drug. When however the total 24 hourly output is taken salyrgan is seen to cause a slight increase in urine output and in total chloride excretion.
Case 3 shows a definite diuresis; the percentage of chloride in the urine is diminished but this is not due to increased water output, for there is also a marked reduction in the total chloride output. The blood chloride is lowered. This case does not appear to have responded well to salyrgan in so far as salt excretion in the urine is concerned. There is however a loss of weight accompanying the water diuresis.
In case 5, (markedly contrasting with case 3) there is actually a diminished urine output under the action of salyrgan but the urine concentration of chloride is increased. The total chloride excretion is also increased. Blood chloride is again lowered. There is a drop in weight which suggests that an increased excretion of chloride is sufficient, a t any rate in this case, t o cause decrease in weight (oedema) even though urine output is diminished. Pre- sumably water was lost by other channels for if this were not so, an increased chloride excretion and a concurrent water retention
28 I . H A R R I S , E. L . R U B I N and J . S . L A W R E N C E .
would result in a marked disturbance of the osmotic pressure of the blood.
From table I i t appears that salyrgan acts in one of two ways: either by increasing the urinary output, or by increasing the capa- city of the kidney for passing urine of a higher chloride concentra- tion. In any case, a marked increase in the total chloride excre- tion is nearly always found. Blood chloride in every case is lowered as a result of the administration of salyrgan.
Table 11.
(Fluld Intfike = 120 ozs.)
Case 2 $ 3 * 4 ' 5 $ 6 $ 7 * 8 * 10 @ 11
12
Haemoglobin % '
NaCl
89 55 81 76 66 74 81 78 80 79
NaCl + Salyrgan
77 49 87 77 62 68 77 77 74 79
Showing the. action of Salyrgan on the concentration of the blood. (Under same conditions as table I).
The data collected from haemoglobin determinations suggest that the blood becomes diluted under the action of salyrgan for (as was the case after NaCl when compared with normal conditions) the haemoglobin percentage is lowered.
The presence of a hydraemia together with the loss of weight which salyrgan brings about suggests that the drug effects a trans- ference of fluid from the tissues to the blood and th6nce to the kidneys.
S A L Y R G A N A N D A M M O P I ~ K I M C H L O R I D E I N C A R D I A C o E D E M A . 29
- -
56
57
58 59 60
61 62 63
64 do. 65 -
Table 111.
Showing Effect of Saiyrgan on total serum base.'
Na - 142
147
138 148 149
142 145 143
145 141 140 -.
Observation
Ca - 4.3 K 5.1
5.2 4 . 1 5.3 Ca 4.6 4.5 4.7 K 5.6 5.1 4.5 -
I
c1 -
100
102
100
103 106
-
102 99
100 -
- Bas -
159
1 50 159 161
154 157
158 153 152 -
- Hb -
112
66 132 80
78 81
101 102 98 -
4 hours after Salyrgan - Na - 138
136 142 145
139 138 140 -
- Ca - 3.4
Ca. 4.8 4.7 4.7 K 5.1 4.5 4.5 -
- c1 -
100 103
98 104 100 -
- Bast *
148 154
151 150 152 -
- Hb --
76 81
109 108 107 -
!4 hours after Salyrgan
Na Base
151 163
147 159 149 160 142 156
(Hb = Haemoglobin.)
Table I11 shows the effect of salyrgan bn total serum base. I t will be seen that the bases are lower four hours after injection and are normal and possibly higher after twenty-four hours. It is possible that the bases may appear lower four hours after the injection because of the hydraemia. In our series of cases how- ever there has been hydraemia even after twenty-four hours, although Crawford and McIntosh (8) found a concentration of the blood after twenty-four hours.
Expressed as m.eq. per litre.
30 1. H A R R I S , E. L . R U B I N and J . 9. L A W R E N C E .
1st day 2nd D
3rd, e
4th P
1st day 2nd 3rd B
4th D
1st day and 0
3rd D
4th n
1st dal 2nd 9
3rd Q
4th D
Table IV.
Effect of Salyrgan on the Urine (24 Hourly Output). - Case
57 Oedema +++
65 Oedema
+
58 Oedema +++
66 Oedema ++
T.B.=Total Base, Wt.=in Ibs & ozs.
. Salyrgan was given an the first day I
each 4-day period, 2.0 cm3.
Table IV demonstrates the enormous increase in the urine in excretion of base after salyrgan. That base excretion is increased after acidifying diuretics is known, but so far as we are aware i t has not been demonstrated that this happens under salyrgan. In some instances it will be seen that the base is increased even on the fourth day after salyrgan. The effect in this case may simply he an indirect one. Salyrgan having once given rise to diuresis, the latter continues for a time after the effect of the drug has worn off.
S A L Y R C A N A N D A M M O N I U M C H L O R I D E I N C A R D I A C O E D E M A . 31
I Highest
Blood pH Conc. of
Urine 'rpur Chlor. in Chloride a rs.
Ammonium Chloride.
Weight lost Total Chloride output after
NaCl+NH,C1 i n grams
Table V.
(Fluid Intake=120 02s.)
Comparing the Effects of the administration of (a) NaCl, with (b)
Following the administration of ammonium chloride, the urinary output is increased. There is no definite increase in the concentration of chloride in the urine but i t must be kept in mind that there is an increased diuresis and therefore the percentage of salt in the urine need not necessarily be high. The total chloride excretion is increased. ,
The outstanding feature of this diuretic is the fact that the blood chloride is definitely increased under its influence. In this, i t contrasts strongly with salyrgan under whose influence the blood chloride is diminished. There is a decrease in weight when ammo- nium chloride is given, but in some cases this is not marked.
In ounces. a Expressed as mg o/b NaCI.
32
Highest Urine Output
as % Fluid Intake
I. HARRIS, E. L . RUBIN and J . S. L A W R E N C E .
Ammonium Chloride produces a marked increase in urine output and a definite increase in the concentration of chloride in the urine. The decrease in the alkalinity of the blood under NH,C1 is also shown. There is some decrease in weight, but on the whole, this is not marked. These cases, however, were not under treat- ment with salt and water and therefore not under artificial oedema. Under such circumstapces only moderate changes in weight can be expected.
' Expressed as mg % NaCI.
S A L Y R C A N A N D A M M O N I U M C H L O R I D E IN C A R D I A C OEDEMA. 33 Table VII.
Comparing conditions under observation with those resulting from the administration of NH,CI,
Blood Weight lost after Chluride Ex. F. I. in g r a m
F. I. F. I. Mod.1 Ex. Ibs. 02s. Mod.\ Ex.
p H
12 6.2 10.0 1 - 11.7 15.6 2 8 11.4 12.8
- 7.27 1 - 17.2 11.8
1 - 10.4 10.4 (gain)
3 8 - - (gain)
7.35 -(gain) 8 9.2 10.1 7.35 7.28 D 8 15.1 15.0 7.31 7.32 u 16 9.0 11.0 7.21 7.26 v 2-8 12.0 11.8
34 I . H A R R I S , E. L. R U B I N and J. S. LAWRENCE.
Comparing the effects of (a) NH,Cl with moderate fluid intake, with (b) NH,C1 with excessive fluid intake.
Urinary output is relatively diminished under ammonium chloride when excessive fluid is given. The concentration of chlo- ride in the urine is also lower, but this may be due to the fact that the actual urine output is greater when excessive fluid is given than-when the fluid intake is moderate. As far as total chloride output under excessive fluid intake is concerned, the great majority of cases show an increase in salt output.
On the whole, blood chlorides are rather diminished when a large amount of fluid is taken, but this is not constant.
The weight does not alter much under varying conditions of fluid intake, but there is a tendency in most cases to a slight rise when the fluid intake is large. One cannot expect marked changes in weight under normal conditions when there is neither artificial nor pathological oedema. But the impression one gets is that the intake of a large amount of fluid acts adversely under this diuretic.
32 33 33a 34 35 36 37 38 40 41 42 42
Total Base after Ammonium Chloride. Table IX.
Effect of NH,CI on blood in lion oedema cases (Moderate Fluid Intake)
S A L Y R O A N A N D A M M O N I U M C H L O R I D E I N C A R D I A C O E D E M A . 35
Under ammonium chloride and ordinary fluid intake there is a concentration of the blood as is shown by the liaemoglobin content. The bases ought therefore to be correspondingly increased. I t is however found that they are actually diminished. I t is clear therefore that the diminution of base is even inore pronounced than may appear from a simple comparison of the figures between observation and under conditions of ammonium chloride. Of the individual bases which are affected calcium does not show a defi- nite diminution. Sodium and potassium which have been thrown out in order to counteract the effect of acidosis are definitely dimi- nished.
101 100 103
100 98
100 100 100 102 100 98
Table X. Effect of NH,Cl on blood in 11011 oedema cases.
Fluid Intake = 1200 02.
-
72 73
82 71
82
=
32 33 33a 34 35 36 37 38 40 41 42 42 -
102 100
103 102 105
99 104
LO4
- 77
70 70 70
76
80
0 b s e r v a t i o 11
134 148 146 146 144 137
140 145 143 144
- Ca - -
4.9 5.1 4.8 5.3 5.3 5.3
4.9 4.7 -
- - -
4.3
5.7 4.6 4.7 4.8
4.1 4.8 4.4
Base' - 146 158 158 159 156 149
152 156 155 155
Ammoniuin Chloride and Water 1
~-
Base' 7
151 153
152 152 156
_-
Under ammonium chloride and excessive fluid intake however the bases are normal or slightly increased. This is borne out by clinical experience. Clinically the effect of these diuretics if given with large quantities of fluid is less pronounced than when given under conditions where the fluid is restricted. Under ammonium chloride and water sodium is definitely increased in comparison t o cases where the same drug has been given under fluid restriction.
' Expressed as in.eq. per litre of serum.
36 I . H A R R I S , E . L . R U B I N and J. 9. L A W R E N C E .
Calcium however seemed to be diminished. Chloride is somewhat increased under ammonium chloride, as would be expected in a condition of anhydraemia.
Haemoglobin determination too shows that under water and ammonium chloride there is a hydraemia in comparison to cases under ammonium chloride with restricted fluid. Under sodium chloride and water there is of course an increase of sodium, the protein is diminished, showing that there is hydraemia.
Table XI shows the total base in the urine after ammonium chloride. I t will be seen thai there is a pronounced increase in the excretion of total base after the administration of ammonium chloride.
S A L Y R G A N A N D A M M O N I I ' M C H L O R I D E I N C A R D I A C O E D E M A . 37
Discussion.
In the cases referred to in this paper, salyrgan produced hydraemia and ammonium chloride produced a thickening of the blood. Yet both drugs produced diuresis in which chloride as well as water excretion was augmented. The conditions under which the patients were treated under each drug were comparable, as far as possible, in every respect. I t follows tha t either con- centration or dilution of the blood may exist during diuresis.
There can be little doubt, from work already quoted, that salyrgan acts on the kidney itself. I t is said tha t chloride and water are filtered out of the blood stream by the glomeruli normally, but tha t their reabsorption is prevented by the diminished affinity for them of the tubular epithelial cells. On the other hand, i t may act by making the kidney filter more permeable or by causing increased pressure in the kidney circulation - a suggestion to which some animal experiments point. The finding of .Jackson (7) of an increased blood pressure (in dogs) in interesting, and his con- clusion tha t the drug acts by direct stimulation of smooth muscle fibres, possibly accompanied by mild stimulation of the endings of the sympathetic nerves. In our cases no significant or constant changes in blood pressure were found after the injection of salyr- gan, but a quickening in the heart rate was observed in most cases.
While its action on the kidney itself cannot be denied, salyrgan has been called a tissue-diuretic and evidence has been quoted in support of an extra-renal effect produced by this drug. Its action is said to be due to the diminished affinity of the tissue colloids for water which passes into the blood stream so tha t the blood becomes diluted. The hydraemia found in our cases lends support to this view. I t may be said therefore that salyrgan diuresis is probably due to the action of the drug on extra-renal tissues in addition to its action on the kidney itself.
The increase in salt excretion in the case of ammonium chloride is not due to the added amount of chloride content of this drug, since there is already a large quantity of chloride in the form of sodium chloride which the kidney cannot deal with and therefore is taken up into the tissues forming oedema. The total output of salt is increased, but i t cannot be said tha t this fact is due to increase of diuresis, which permits sodium chloride t o pass owing
38 1. H A R R I S , E. L. R U B I N and J . S. L A W R E N C E .
t o a diluted urine; for even in cases where the urinary output is diminished salt excretion is still increased. Neither can it be said that the urinary output stands in a certain relation to salt excreted, for in some instances the urinary output is large and the salt excreted only moderate. Moreover after the administration of ammonium chloride, the kidney excretes large quantities of potassium which a t least contributes to the resulting diuresis. The practical deduc- tion to be made suggests that beneficial factors of these diuretics are not entirely due to improvement of salt excretion by the kidney. We may therefore be sure that salt-free diet alone would not pro- duce the same effect on oedema as diuretics do.
Although ammonium chloride is in some respects a tissue- diuretic like salyrgan, in that a decrease in the alkalinity of the blood (in the case of NH,Cl) bring6 the tissue-proteins nearer to their iso-electric point so setting free base and water, this never results in hydraemia. The contrast between the dilution of the blood which follows salyrgan and the concentration of the blood after ammonium chloride has already been noticed. Salyrgan must act on the kidney because it facilitates salt excretion by the latter. I t must also act on the tissues since otherwise the hydraemia could not be explained.
In the case of ammonium chloride the blood being depleted of fluid and concentrated, its osmotic pressure rises, this consti- tuting an ideal condition for the tissue fluid to enter the circulation. As already noted, the affinity of the tissue colloids for base and water has been lowered by the existing acidosis so that the bans- ference of fluid from the tissues to the blood is facilitated. Under such conditions the favourable action of the acidifying diuretics in oedema is apparently due to their dehydrating action. With these considerations in mind, it would be reasonable to surmise that if the thickening of the blood following ammonium chloride acidosis were by some means prevented from occurring, the efficacy of this drug as a diuretic would be diminished.
The administration of large quantities of water to cases of oedema has been found not to increase the oedema a t all, so long as sodium chloride is strictly withheld. (1) Yet if the acidifying diure'tics are accompanied by the administration of large quantities of water, the effects of these drugs is, in some cases, not pronounced. This is probably due to the fact that :i large fluid intake tends to
S A L Y R C A N A N D A M M O N I t I M C H L O R I D E I N C A R D I A C O E D E M A . 39
prevent the dehydration which ammonium chloride brings about. A large water excretion is immediately counterbalanced by the increased fluid intake, with the result that the effect of the higher osmotic pressure of the blood on attracting fluid from the tissues is not so marked as when fluid intake is moderate. The comparative figures given in the Tables certainly lend support to this suggestion.
I t is known (and illustrated by one case in this paper), that the production of ammonium chloride acidosis is not always fol- lowed by diuresis. Ammonium chloride may do definite harm in advanced heart failure with a low arterial tension and a damaged kidney, as in these cases there is already a certain degree of acidosis. In cases of pronounced heart failure acidifying diuretics ought not to be given without determination of the pH of the blood.
Conclusions.
1. Salyrgan acts by increasing urinary output or by increasing
2. After the injection of salyrgan there is hydraemia. 3. The serum bases are diminished up to 4 hours after the
injection of salyrgan probably owing to hydraemia. They are about normal after 24 hours.
4. In the urine the bases are greatly augmented as a result of the injection of salyrgan.
5. Ammonium chloride acts by increasing urinary output or by increasing the excretion of salt.
6. There is a concentration of the blood under the influence of ammonium chloride.
7. Following the administration of ammonium chloride the serum bases are definitely diminished when fluids are restricted, and about normal when the fluid intake is excessive; and
the excretion of salt, or both.
8. The excretion of base in the urine is augmented.
We should like to express our gratitude to Professor de Wesselow for looking over the paper, to Professor H.E. Roaf for valuable suggestions, and also to Dr. R. W. Brookfield.
40 I . HARRIS, E. L. R U B I N and J. S. L A W R E N C E
References.
1. Harris, I . and Mennie, R.; Lancet, Dec. 31, 1932, p. 1427. 2. Peters and Van Slyke; Quantitative Clinical Chemistry, p. 1024. 4. Reiss; Arch. f . d. Exper. Path., 1904, LI. 5. Neuhausen and Reoch; Journ. Biol. Chem., 1923, LV, 353. 6. Korangi and Richter; Physikalisrhe Che- mie u. Med.. Leipzig, 1907, p. 191. 7. Jackson, D. E.; Journ. Pharmacol. & Exper. Therapeut., 1926, 29, 471. 8, Crawford, J. H. and McIntosh, .I. I . , Journ. Clin. Invest. 1924-5, I , 333.
