Masing(2), who points out that 600/0 to 700/0 of the glucose of the

Transcription

1 NOTE ON THE PERMEABILITY OF RED CORPUSCLES FOR GLUCOSES AND GLUCOSAMINE. BY SHUZO KOZAWA, M.D. (From the Medical College, Osaka.) I HAVE shown in a previous paper that the red corpuscles of man and of monkey are markedly, and those of the dog slightly, permeable for all hexoses and pentoses when tested in vitro, while those of other animals are impermeable. In spite of this permeability of the red corpuscles of man and monkey, their sugar content always remains below that of the medium in which they are immersed. This statement was confirmed by Masing(2), who points out that 600/0 to 700/0 of the glucose of the medium can penetrate into the red corpuscles. According to Michaelis, Rona and Takahashi(3,4) in the dog the sugar content of the red corpuscles may be higher than that of the serum. If sugar penetrates from the serum into the red corpuscles the sugar content of the latter should never be higher than that of the serum. Results such as those obtained by Michaelis must therefore be ascribed either to an increased production of sugar in the corpuscles or to increased glycolysis occurring in the plasma. I have endeavoured to throw some light on the question of the distribution of sugar in the red corpuscles and plasma respectively by observations on the distribution in conditions of artificial and natural hyperglycemia. B ertrand's methods were used for the estimation of sugar, as described in my previous paper. Hyperglyesamia was induced in the rabbit and dog by the subcutaneous injection of adrenalin; in man I utilised the hyperglycamia of diabetics for this purpose. 1. Experiments on rabbits. The normal content of sugar in the red corpuscles and plasma of these animals has been repeatedly determined. The following observations were carried out as a control:

2 RED CORPUSCLE PERMEABILITY. 265 TABLE 1. in 100c.c. Normal blood. in 100cc K1853 gr. oo gr. 1 : gr. oo gr Table II shows the distribution of sugar one hour after the subcutaneous injection of adrenalin. TABLE II. Blood in adrenalin-hyperglycemia. in 100 c.c. in 100 c.c. 1. 0* a : : : : 14 This table shows that the sugar conteint of the red corpuscles remains normal while that of the plasma rises. The results concur with those obtained by Rona, Takahashi and Hober on circulating blood and with my own experiments in vitro as shown in T'able III. TABLE III. Blood with addition of glueose in vitro. in 100 c.c. in 100 c.c. in 100 c.c. blood 1. 0*6045 0* X 2. 0*6642 0* We see therefore that hyperglycsemia in the rabbit involves an increased amount of sugar in the plasma only and not in the corpuscles, and that the rabbit's red corpuscles have little or no permeabilitv for grape sugar whether in vitro or in circulating blood. 2. Experiments on dogs. In dogs the sugar content of the red corpuscles is always higher than that in rabbits, as is shown by the following observation on dogs: TABLE IV. in 100 c.c. in 100 c.c. 1. Morphiumnarcosis : 4 Adrenalin 0005 injection : Morphiumnarcosis :11 Adienalin injection : 5 3. Morphiumnarcosis :10 Adrenalin injection : 6

3 266 S. KOZA WA. In this case subcutaneous injection of adrenalin increases the sugar content of the plasma, but only to a slight degree that of the red corpuscles. On the other hand the following experiments in vitro show a more marked penetration of the red corpuscles by sugar. TABLE V. Blood with addition of glucose in vitro. in 100 c.c. in 100 c.c. in 100cc. blood plasma red corpuscles Proportion : : : : Experiments on man. Many investigators, such as Tachau(6), E. Frank(7, 8), Hollinger(, Rolly and Oppermann(lo), have found very evident increases in the sugar content of the human red corpuscles in hyperglycamia, and cases have been recorded by Tachau, Hollinger, Frank and Bailya(l) in which the sugar content of the corpuscles was even higher than that of the serum. The following table shows results obtained on cases of diabetes: TABLE VI. Volume of in 100 c.c. in 100 c.c. red corpuscles Glycosuria in hmmatocrit : : / : / : / O : 2-2 trace 54-5 It is evident from this table that human corpuscles in circulating blood are easily permeable to grape sugar. The sugar content of the corpuscles is always increased in hyperglycsemia, but neither here nor in my experiments in vitro have I come across any case in which the sugar content of the corpuscles is greater than that of the serum. In hyperglycamia the volume of the red corpuscles is increased, as shown by determination with the heematocrit. The same phenomenon can be observed outside the body. In normal blood the ratio of the corpuscle volume to the plasma volume is about 1: 2, but in diabetics this may be increased 1 : 1 or even more. 4. Experiments with glucosamine. Having shown that the red corpuscles in man and monkey are permeable to all hexoses and pentoses, and that the same applies in less

4 RED CORPUSCLE PERMEABILITY. 267 degree to the dog's corpuscles, but not to other animals, I have investigated the behaviour of corpuscles to glucosamine. For this purpose a smfall quantity of an isotonic solution of glucosamine was added to defibrinated blood and left 30 minutes to 1 hour. The distribution of the glucosamine in corpuscles and plasma was then determined by Bertrand's method. Determination of the volumes of corpuscles and plasma were also made with the hsamatocrit. In the goat, horse, and rabbit the corpuscular volume is not increased by the addition of an isotonic solution of glucosamine. We may therefore conclude that the corpuscles of these animals are impermeable to this substance as they are to glucose and pentose. In man on the other hand the corpuscular volume is increased by the addition of glucosamine, showing that human corpuscles are permeable to this substance. Goat. After 2hrs. TABLE VII. (a) Experiments with hmmatocrit. Red corpuscles c.c. Red corpuscles 3.0 c.c. Isotonic glucosamine solution 1l0 c.c /0 NaCl solution 3*0 c.c /0 NaCl solution c.0. constant volume in haematocrit t after centrifug After 4 hrs Hor8e. 15 mins hrs Rabbit. 18 hrs X0 24 hrs Man. 30 mins *0 18 hrs This conclusion is confirmed by the following results of chemical analysis: TABLE VIII. (b) Chemical analysis after addition of glucosamine to the blood. Glucosamine Glucosamine in 100 c.c. in 100 c.c. Rabbit gr gr. oo,, ,, ,, 1: 3*4 Goat ,, , o, 2. 0O ,, 1: 6-2 Dog ,, ,, Man 02733,, ,, 1 11 (Note:-glucosamine calculated as glucose.) We see that in the red corpuscles of the goat, dog, and rabbit, the reducing substance of the corpuscles remains unchanged, whereas in the human corpuscles the reducing substances were increased and approximated to the percentages found in the plasma.

5 268 S. KOZAWA. CONCLUSIONS. 1. The permeabilitv of the red corpuscles was determined by three methods: the haematocrit, chemical analysis in addition, chemical analysis in hyperglyceemia. In man, the red corpuscles in the circulating blood are easily permeable for blood sugar; in the rabbit they are impermeable; in the dog they were found to be impermeable by the hesmatocrit method, but to be slightly permeable by the chemical analysis methods. 2. In the hyperglycammia of diabetics the volume of the red corpuscles is increased. 3. No case has been observed in which the sugar content of the red corpuscles was greater than that of the medium in which it was immersed. 4. Human red corpuscles are permeable to glucosamine, whereas those of the rabbit, dog and horse are impermeable. REFERENCES. (1) S. Kozawa. Biochem. Ztschr. 60. (2) Masing. Pfluiger's Archiv, 159. (3) Rona and Michaelis. Biochem. Ztschr. 18. (4) Rona and Takahashi. Ibid. 30. (5) Hober. Ibid. 45. (6) Tachau. Ztschr. f. klin. med. 69. (7) Frank and Bretschneider. Ztschr. f. physiol. Chem. 71.' (8) Frank. Ibid. 70. (9) Hollinger. Biochem. Ztschr. 17. (10) Rolly and Oppermann. Ibid. 49. (11) Baily. Arch. of internal Med. 23.