blood. The main experimental results reported by Bayliss showed

Transcription

1 THE USEFULNESS OF GUM ARABIC AS AN INFUSION LIQUID. By J. A. MAAS. From the Physiological Laboratory, University of Utrecht. (Received for publication 1st September 1938.) PHYSIOLOGICAL salt solutions to which 6 per cent. gum Arabic had been added were used during the Great War, , to replace blood in wounded soldiers. This treatment, suggested by the work of Bayliss [1918], aimed at the maintenance of the colloid osmotic pressure of the blood to ensure the retention of fluid in the circulatory blood. The main experimental results reported by Bayliss showed that after the withdrawal of 70 per cent. of the blood from cats and its replacement by g.a. the animals survived, whereas removal of 30 per cent. of the blood without subsequent infusion of g.a. led to death. These results were confirmed by Hurwitz [1917] and Barthelemy [1919]. After the war, various objections were raised against this method of blood substitution, emanating for the most part from the United States of America and culminating in an article in 1922 appearing in the Journal of the American Medical Association. The criticisms may be conveniently summarised as follows: (1) Increase of the sedimentation rate and agglutination of the erythrocytes [Kruse, 1919; Hanzlik and Karsner, 1922]. (2) Slow recovery of the normal amount of fibrin in the blood [Forster and Whipple, 1922]. In replying to some of these criticisms Bayliss [1922] laid stress on the necessity for selecting reliable samples of g.a. for preparing the solution according to a standard prescription. Meanwhile Zondek [1921 a, 1921 b] attributed the good results of gum saline to the amount of Ca it contained, and agreed with the suggestion of Nonnenbruch [1921] that the colloidal nature of g.a. was of no importance for the retention of fluid in the circulatory system. Kiilz [1921], on the other hand, gave no support to these views, and pointed out that sodium arabinate solutions behaved similarly to those of g.a.; moreover, he showed once more that the injection of g.a. resulted in a loniger retention of circulating fluid than injections of saline solutions. Ueki [1924], whose work later received criticism from Hoitink [1934], also Bricker, Suponitzkaja and Tscharni [1926] have also reported favourably on the use of g.a. The latter investigators withdrew 25 c.c. of blood/kg. body wt. from rabbits 315

2 316 Maas and compared the effects of saline solution and g.a. injections on the blood-pressure and blood composition. Their results led them to favour the injection of the colloid solution. The work of Huffman [1929] agreed with this view, which led Hanzlik [1929] to stress the objections of g.a. injections on the grounds that the experience of U.S.A. medical officers of the method was unfavourable. Agglutinisation of the erythrocytes as a source of danger with g.a. infusions in the dog was stressed by Hoitink [1938]. In the research undertaken by ourselves we did not attempt to determine whether g.a. is to be preferred to non-colloidal solutions for the replacement of blood, but to determine how far there is any physiological qualification for the injection of g.a. into a healthy organism. According to Bayliss, a solution of 6-7 per cent. g.a. solution is perfectly harmless to the organism "as may be expected from its chemical inertness." He [1918, p. 85] pointed out that g.a. is a mixture of polymerised anhydrides of galactose and of a pentose sugar, arabinose, in varying proportions. Later data [Butler and Cretcher, 1929] showed that g.a. contains galactose in the form of glucuronic acid, 28 3 per cent.; hexose in the form of galacteron, 29 5 per cent.; pentose as arabinose, 34*4 per cent.; and methylpentose as rhamnose, 14 2 per cent. It would appear, therefore, that g.a. solutions do not contain substances harmful to the organism, yet we propose to show later that the deposit of the inorganic ions associated with the arabinate molecule may be of considerable importance, and that relative concentrations of Ca- and Na-ions determine the physiological effect of g.a. solutions. We shall first discuss the results of the experiments in which g.a. of different origin (g.a.i and g.a.ii) was injected into healthy rabbits, which we shall indicate as g.a.i and g.a.ii animals. For comparing the tests, each rabbit was injected into the marginal vein of the ear with 1/80 of its body-weight of g.a. solution, i.e. 1/6 of its total blood volume. The solutions were prepared according to standard prescription [Farrar, 1921]. Some results are summarised in Table I. Four animals treated with g.a.i (Nos. 3 and 6) showed obvious symptoms of illness: the respiration was difficult, often spasmodic and dyspnoeic; the pulse was weak and sometimes hardly countable; the head was retracted and moved synchronously with respirations. Stools were passed and eventually grave diarrhoea followed. The rectal temperature went up to 2 C. above normal. Two of the animals died with severe dyspncea and spasmodic contractions of fore and hind legs. Post-mortem examination revealed that the blood was dark red, as a result of anoxoemia, the weak heart dilated, the liver hyperaemic; the bowels were contracted, and the lungs showed multiple spots which suggested bronchial spasm; signs of embolism were not noticed.

3 The Usefulness of Gum Arabic as an Infusion Liquid 317 a.2 co A.o fot~.,a M.< P-~ 0t 11 u...4.q

4 318 Maas The two other animals remained alive and recovered entirely after three days. The reactions of the animals treated N-ith g.a.lj were quite (lifferent. This gum was well endured; these rabbits reacted hardly or not at all after the injection and wn-ere absolutely free from symptomiis of illness (Nos. 7 and 10). NowA- it was of interest to investigate the cause of the different results obtained on the g.a.1 and g.a.11 aniimals. It was not likely that gum I would contain chemical imnpurities harmful to the organism, as the g.a. -as guaranteed as being chemically puire. For that reason we concluded that the gum itself was responsible for the symptoms of illness. AWe tried, therefore, to solve the problem in the following way: First it appeared from the anialysis of the ash of gum 11 that the inorganic components consisted only of calciumil, which suggested gum II to be a simple arabinate of Ca. For that reason we changed this arabinate of Ca into arabinate of Na after the inethod of Bungenberg de Jong [1933] by precipitating it several times withl alcohol in anl aqueous solution of 10 per cent. NaCl [see also Bayliss, 1918, p. 38]. A 6 per cent. solution of this pure arabinate of Na in 0 9 per cent. NaCl was now injected intravenously into lhealtlhy rabbits and the animals observed closely. The result was startling: all the animals, w-ithout exception. died wvith the same symptom-ls as the rabbits injected with g.a.1 (see Table I, No. 12). The follown-iing experiment was taken as a control: A second injection was administered to two g.a.ii rabbits (Nos. 7 and 10); 5 lhours later, one of them received 17 c.c. of arabinate of sodium, the other one 14 c.c. of arabinate of calcium. The Na-arabinate animal died within two hours with marked dyspnoea and muscular spasms, the Ca-arabinate animal was againi unaffected. The above symptoms, combined with the results of the post-mortem, led to the diagnosis that the aniimals probably died from hypocalcemia. To test this view we determined inll vitro whether Na-arabinate hlas the property of fixing calciumu-ions in a solution of CaCl2. So a pure solution of CaCl2 containing about 12 mug. Ca per 100 c.c. solution approximately as mnucl ionised Ca as serum of rabbits-u%was analysed according to the mnethod of Kramer and Tisdal as modified by Clark and Collip [Hawlk,cE aind Bergeim, 1926, p To 50 c.c. of a solution containing 1226 inlg. Ca per 100 c.c. was added 10 c.c. of 6 per cent. arabinate of sodium. Then the fluid was pressed throuiglh an ultra filter, -hich was guaranteed to be protein-proof. It may be supposed that this filter does not allow the molecules of the gum to pass. An analysis of Ca of the iultra filtrate gave, after recalculationi to the original volume, 3 11 mog. Ca/100 c.c. fluid. So it appears that the arabinate may fix 74-6 per cent. of the originally free Ca-ions. These results suggested a study of the fixation of calcium by Na-arabinate in the blood. Fresh defibrinated blood of rabbits was

5 The Usefulness of Gum Arabic as an Infusion Liquid taken and different amounts of Na-arabinate (6 per cent.) were added and the ultra filtrate analyses for Ca. The calcium fixation shows, if represented graphically, a hyperbolical curve. This curve is of physiological importance, because the physiological Ca minimum in the blood will be reached in a short time, since small quantities of Na-arabinate will fix comparatively more Ca-ions than large quantities. For instance, we found that if 1/8 of the amount of the blood was replaced by Na-arabinate, already 42 per cent. of the free Ca-ions were fixed. How must we interpret this fixation of Ca? From a collqidchemical point of view, the gum solution is to be compared with a negatively charged colloid. So the gum particles will have the property of binding kations on their surface and will be able to change these ions for foreign ions in the surrounding salt solution. A pure Naarabinate in a NaCl solution adsorbs only Na-ions. If now a Ca salt is added, one free Ca-ion in solution will change for two adsorbed Na-ions. This change continues, till a balance between the deposit of the kations on the arabinate molecule and the concentration of the salt in the surrounding fluid has been reached. In this way it will be possible that even a pure Ca-arabinate may fix Ca-ions from the surrounding solution. This only depends on the relative concentrations as was ascertained by Tendeloo [1936]. Another point of interest is the extent of the hydration produced by the deposit of the kations on the arabinate molecule, a factor which will influence the viscosity. For this reason we measured the viscosity of pure Ca- and Na-arabinate solutions in water and in 0 9 per cent. NaCl with the results shown in Table II. It may be concluded that the harmful effect of Na-arabinate (6 per cent.) in 0 9 per cent. NaCl is not due to a viscosity factor since its viscosity is approximately similar to that of blood. Further, the injected gum solution is diluted largely by being mixed with blood, also the fixation of plasma Ca-ions will lead to a still further reduction in viscosity. TABLE II. Temperature 380 C. Water bi. dest Ca-arabinate 6 per cent. in water Ca-arabinate 6 per cent. in NaCl 0 9 per cent Na-arabinate 6 per cent. in water Na-arabinate 6 per cent. in NaCl 0 9 per cent Na-arabinate 4 per cent. in NaCI 0 9 per cent Na-arabinate 2 per cent. in NaCl 0 9 per cent For these rea8ons the calcium fixation in the blood mu.qt be 8,upposed to be the direct cause of the symptoms mentioned above, a view which is supported by the observations demonstrating that these symptoms of illness do not occur if a calcium solution is given intravenously immediately after the gum injection.

6 320 Maas The interchange of Ca has been tested by means of experiments on blood-pressure of which we give the following example: A rabbit weighing 2-5 kg. was anaesthetised with pernocton, 0-6 c.c. intravenously and 1-4 c.c. subcutaneously. The changes of blood-pressure in the right carotid were registered on a kymograph in the ordinary way. The initial blood-pressure (fig. 1) is mm. of mercury (A). A 6 per cent. Na- II FIG. 1.-Influence of an infusion of Na-arabinate upon blood-pressure. A. Initial blood-pressure mm. of mercury. At the first arrow slow injection of Na-arabinate in tho auricular vein. B. After 15 minutes. Blood-pressure has fallen to 60 mm. of merculry. At both arrows injection of CaCl2: slow rising of the blood-pressure. C. After 30 mintutes. The blood-pressure has reached its initial level. arabinate solution in 0 9 per cent. NaCl is injected into the auricular vein at a rate of 4 c.c./min. (4 ). The blood-pressure is not altered until c.c. arabinate have been injected, after which a sudden fall of pressure takes place. Within one minute the blood-pressure falls from 120 mm. to 60 mm. and remains there (B). In this condition the respiration of the animal is difficult and dyspnoeic, and the action of the heart weak. After a period of 15 minutes, 10 c.c. of a solution containing 0.a mg. Ca/c.c. is injected (44). The blood-pressure rises slowly and after 30 minutes reaches its initial level (C). The respiration and heart action are normal.

7 The Usefulness of Gum Arabic as an Infusion Liquid 321 In another experiment it appeared to be possible to regulate the blood-pressure with the amount of Na-arabinate. The animal finally died with violent muscular spasms. A moment before death the pressure had fallen to 40 mm. mercury, whereupon we injected calcium, but apparently too late. Moreover, we tested the influence of Naarabinate on the isolated heart of the frog and the rabbit. In both cases we observed a diminution of the contractions; the result of a fixation of free Ca-ions in the perfusion liquid. In a later publication we shall discuss these experiments in more detail. SUMMARY AND CONCLUSIONS. It may be concluded from the above experiments that to the dangers connected with a gum infusion already known, a new one has been added, namely, the possibility of a calcium fixation in the blood. This occurs especially if a pure arabinate of sodium is used. With gum of unknown origin an interchange of Ca is possible. Furthermore, ions adsorbed on the arabinate molecule, like K and Mg, may easily change with Na-ions of the plasma and cause a disturbance of the physiological balance of the plasma-ions with consequent effects upon the heart. We found a pure Ca-arabinate to be harmless to rabbits. The statement of Bayliss [1920] that "there is no need to add any Ca salt to gum saline, since the gum itself contains sufficient" is incorrect, and either he must have been fortunate in the sample he examined or possibly his practice of dissolving the gum in tap-water (London tap-water contains considerable quantities of Ca) was responsible. REFERENCES. BARTHELEMY (1919). C.R. Acad. Sci. 169, BAYLISS, W. M. (1918). Intravenous Injection in Wound Shock. Longmans, Green & Co., London. BAYLISS, W. M. (1920). J. Pharmacol. 15, 29. BAYLISS, W. M. (1922). J. Amer. med. Assoc. 78, 24, BRICKER, F., SUPONITZKAJA, F., und TSCHARNI, A. (1926). Z. exp. Med. 48, 451. BUNGENBERG DE JONG, H. G., and v. D. LINDE, P. (1933). Biochem. Z. 262,,161. BUTLER, C. L., and CRETCHER, L. H. (1929). J. Amer. chem. Soc. 51, FARRAR, L. K. P. (1921). Surg. Gynec. Obst. 32, 328. FORSTER, D. P., and WHIPPLE, G. H. (1922). Amer. J. Physiol. 58, 393. HANZLIK, P. J. (1929). J. Amer. med. Assoc. 93, HANZLIK, P. J., and KARSNER, H. T. (1920). J. Pharmacol. 14, 379, 425, 449, 479. HAWK, PH. B., and BERGEIM, 0. (1926). Practical Physiological Chemistry, 9th ed., Churchill, London. VOL. XXVIII., NO

8 322 The Usefulness of Gum Arabic as an Infusion Liquid HOITINK, A. W. J. H. (1934). Thesis, Utrecht. HOITINK, A. W. J. H. (1938). Acta neerl. Physiol. 8, 42. HUFFMAN, L. D. (1929). J. Amer. med. Assoc. 93, HURWITZ, S. H. (1917). Ibid. 68, 9, 699. KRUSE, T. H. (1919). Amer. J. Physiol. 49, 137. KULZ, F. (1921). Dtsch. med. Wschr. 49, NONNENBRUCH, W. (1921). Arch. exp. Path. Pharmak. 91, 218. TENDELOO, H. J. C. (1936). Rec. Trav. chim. Pays-Bas, 55, 227. UEKI, R. (1924). Arch. exp. Path. Pharmak. 104, 239. ZONDEK, S. G. (1921 a). Biochem. Z. 116, 246. ZONDEK, S. G. (1921 b). Dtsch. med. Wschr. 30, 855.