SOCIETY, PHYSIOLOGICAL PROCEEDINGS. December 13, 1913.

Transcription

1 PROCEEDINGS OF THE PHYSIOLOGICAL December 13, SOCIETY, Studies on beri-beri. The probable role of vitamines in the process of digestion and utilisation of food. By CASIMIR FUNK. Recently Abderhalden and Lampe in an article published in Zeitsch. f. die gesammt. exper. Medizin, I, , have pult forward the view that beri-beri might be due to toxic products present in the rice. This view already expressed by several workers is up to the present moment not justified by any experiment. Abderhalden and Lamp6 have found a new fact which in their opinion is very much in favour of the intoxication-theory, namely, pigeons fed on cooked rice live much longer without developing beri-beri than pigeons fed on raw rice. Their explanation was that during the cooking some toxic products are either destroyed or extracted. I have repeated these experiments and have found them to be correct. Whereas the pigeons fed on raw polished rice lived on the average for 29 days, pigeons on cooked rice lived for 43 days. We thus see that there is a considerable delay in the onset of the disease in birds fed on cooked rice, and although the destruction or extraction of a hypothetical toxin during the process of cooking has been offered as an explanation of the fact, I consider it is more reasonable to suippose that cooked rice not being so natural a food for birds as the uncooked grain is less readily assimilated, and consequently less of the body vitamine is mobilised during the assimilation of the food. A second, still more probable, explanation of this fact c

2 xxvi PROCEEDINGS OF THE PHYSIOLOGICAL is that cooked food being richer in water contains less nutritive elements, compared with the same weight of uncooked food, and therefore requires less vitamine to be utilised. For purpose of testing these hypotheses, several batches of pigeons were put on amounts of rice varying from i grm. to 30 grms. a day, an experiment which was already undertaken by several investigators, who however did not concord in their results and in their interpretations of the results obtained. According to my experiments, pigeons developed beri-beri in a period of time depending entirely on the amount of rice given. Those which had 30 grms. developed the symptoms first, those with the smallest amount came last. From these facts I conclude that the onset of the symptoms is in a direct relationship with the amount of food metabolised, during which process the vitamine of the body is used up. The question which constituents of diet require the help of vitamine for their assimilation will be studied in a new series of experiments which are at present being performed. The already established fact that natural foodstuffs which are rich in nitrogen, like yeast, peas, maize, are comparatively rich in vitamines, indicates clearly the line to follow. It is a well-known fact that both in men and birds living on identical, but vitamine-free, diet the time the disease takes to develop varies. In some of the cases it appears early, in others it is delayed. These differences were explained in my previous papers by the variations in the vitamine-stock of the body, and above experiments would seem to show that there are other equally important factors which we must take into consideration, namely, the amount and the natuire of the food consumed. At the same time as the above-mentioned rice experiments were made two batches of pigeons were put on the synthetical diet such as was used in experiments on growth by Osborne and Mendel and Hopkins. One batch was given an uncooked mixture, the other the same mixture cooked. On this diet, very rich in nitrogen (caseinogen) and up to the present moment considered in many metabolism experiments to be a complete diet, the pigeons developed unmistakable beri-beri symptoms even sooner than pigeons fed on polished rice. It is clear therefore that even a diet rich in nitrogen, sugar, starch, fat and salts (Osborne and Mendel's last salt mixture, including the rare inorganic constituents of the body) produces beri-beri when the vitamines are absent; the richer such a diet is, the sooner the symptoms appear. Further experiments on this subject are in progress.

3 SOCIETY, DEC. 13, *si The effect of CO2 on the dissociation curve of hemoglobin. By J. BARCROFT and J. H. MEANS. The following dissociation curves have been found for carefully dialysed oxyhbemoglobin in the presence of varying quantities of C02 at 400 C. Percentage saturation with oxygen at the following pressures: CO2 pressure mm.- Oxygen pressure mm. 0 7T ' '5 28' '5 45' ' ' ' ' These curves correspond to the following valves of n, the average number of molecules of hemoglobin in a clump, and K, the equilibrium constant in the equation: y _ Kxn Kxe CO2 pressure mm. 0 7' n 1 1'778 2'2 2'5 2'7 K '111 '0062 '00157 ' ' The degree of aggregation of the molecules is very sensitive to CO2 at low concentrations of the gas, but relatively insensitive when it attains the figure 2'5, that which obtains for blood. On the estimation of,8-oxy-butyric acid. By E. L. KENNAWAY. (Preliminary communication.) In Shaffer's method (Journ. Biol. Chem. v. 1908) the acid is oxidised by potassium bichromate and sulphuric acid to acetone, which is distilled off and estimated by means of iodine and thiosulphate. Shaffer obtained approximately correct yields by this method (98'8 to /,). It appears preferable to utilise Scott-Wilson's mercuric cyanide method (Journ. Phys. XLII. 1911) for the estimation of this acetone, since the reagent is less liable than is iodine to be affected by the presence of other substances.

4 xxviii PROCEEDINGS OF THE PHYSIOLOGICAL.The accuracy of the Scott- Wilson method. Scott-Wilson found the results by his method to be about 30/0 too low. The following results are taken from a large number of tests which have been applied to this method in the present investigation. Acetone in 10 c.c. (1) gm. acetone weighed and diluted to 1 litre mg. (2) 100 c.c. of above solution estimated by iodine method (1) (2) (3) 10 c.-. estimated by Scott-Wilson method. Mean of ten estimations (max , min ) (4) 5 c.c. estimated by Scott-Wilson method. Mean of ten estimations (max , min ) The application of Scott- Wilson's method to the estimation of 8-oxy-butyric acid. When the acetone is distilled through caustic soda as recommended by -Scott-Wilson, the iodine and the mercuric cyanide methods show fairly close agreement in the case of urine; when blood is treated in the same way, other iodine-binding substances besides acetone are formed. This method has been used in the investigation of a series of cases of acidosis (Kennaway, Pembrey and Poulton, Journal Phys. XLVII. 1913). Milligrams acetone from aceto-acetic acid+acetone from,-oxy-butyric acid iodine Scott-wilson iodine Scott-Wilson method method method method Urine Blood The accuracy of Shaffer's method. The method used in these estimations was then tested with known amounts of /8-oxy-butyric acid in order to confirm Shaffer's statement quoted above as to its accuracy. The sodium salt was prepared from the inactive acid, and recrystallised four times from alcohol; it gave

5 SOCIETY, DEC. 13, practically theoretical figures for C and H on combustion. When oxidised by Shaffer's method the yield of acetone was from 5 to 100/0 too low. While these experiments were in progress, Shaffer published a second paper (Journ. Biol. Chem. Nov. 1913) showing that his earlier results were incorrect. The results given in the third column below were obtained in the present investigation. Shaffer, 1908 Shaffer, 1918 E. L. K. Yield of acetone from j3-oxy-butyric '9 900 acid as percentage of theoretical [ amount xxixx In some cases more accurate results are obtained by adding the salt to normal urine; the result given by the urine alone is of course subtracted. The increase in yield is due to concentration by the bulk of the precipitate of lead compounds; the amount of acetone obtained is from 94 to 96 0/0 of the theoretical amount. Note on oedema. By W. BURRIDGE. There are at least two types of oedema associated with the limbs of frogs. These two types are: (a) the oedema of acidosis or function, (b) the oedema of perfusion or pressure. They are distinguished from each other by their actions on the functional capacity of muscle. The oedema of acidosis is accompanied by a diminution in the mechanical response of directly excited muscle proportional to the development of the oedema. The indirect response is affected very much more than is the direct. Neither response of muscle appears to be particularly affected by the second type of oedema. c 3

6 xxx PROCEEDINGS OF THE PHYSIOLOGICAL The electrocardiogram of the tortoise ventricle. By W. A. JOLLY. From string galvanoineter records of the electrical beat of the tortoise ventricle in a state of alternation, it is possible to determine the form of the electrical disturbance at a point in the cardiac musculature. It consists of a brief positive change followed by a negative change which endures during activity. The usual form of the electrocardiogram gives the algebraic sum of similar changes occurring under the two electrodes and differing slightly in time relations. Curves a and b of the diagram represent two successive alternating responses of the isolated tortoise ventricle to induction shocks. The leading off electrodes, proximal and distal, are applied to the right and left edges of the ventricle respectively. The metal stimulating electrodes are applied to the surface of the ventricle at a point between the leads. Curve b is an electrocardiogram of the usual form. Curve a gives the electrical disturbance under the proximal electrode alone and consists of a downward (positive) deflection followed by a negative deflection. Curve c, the ordinate difference between b and a indicates the form of the electrical distuirbance under the distal electrode.

7 SOCIETY, DEC. 13, xxxi Note on summation. By W. BURRIDG E. Calcium salts greatly favour a summation of contractions in cardiac muscle. The ventricle of the frog after appropriate treatment with calcium may be made to assume a condition resembling tetanus and show evidence of fatigue. These processes are assisted by potassium chloride. Fig Ventricle tetanised. + Tetanising current discontinued. Time in 10" intervals. Calcium salts may depress the amplitude of ventricular contraction elicited by a single induction shock and greatly increase the contraction obtained by a series of such shocks (tetanus). In the ventricle treated with calcium salts the series of mechanical responses to two consecutive stimuli sent in at gradually lessening intervals may approximate to that described by Von Kries in skeletal muscle. Chloral hydrate leaves the heart in such a condition that the effective action of calcium is greatly increased. The capacity of the chloralised heart to sum contractions etc. (Rohde) results from the accompanying increased effectiveness of calcium. Alcohol and ether may leave the heart in a condition such that summation of contractions readily occurs. Small concentrations of chloroform first lengthen and then shorten the refractory period of the ventricle of the perfused heart. Traces of alkali increase the effective action of calcium (Burridge) and favour a summation of contractions.

8 xxxii PROCEEDINGS OF THE PHYSIOLOGICAL Electrocardiogram of horse. By A. D. WALLER. Recent publications on the electrocardiogram of the horse,- by J. Norr (Ztschr. f. Biol. Bd. LXI. p ) and by R. H. Kahn (Pfliger's Archiv, Bd. CLIV. P ) have recalled to my memory a demonstration made on December 19, 1889 (Du Bois Reymond's Archiv, p ) to the Berlin Physiological Society. The object of that demonstration was to show that in man as compared with quadrupeds (dog and horse) by reason of the greater obliquity of the heart and therefore of its electrical equator and currentaxis, the contrast between favourable and unfavourable leads is much less pronounced on quadrupeds than upon man. Upon man, it was shown at the meeting, that the two hands, the mouth and the left hand, the right hand and either foot constitute strong leads (wurksame Anordnung), the two feet, the mouth and the right hand, the left hand I~~~ ~ ~ ~~~~~~~~~~~~~~~~ The five leads of a horse, R. ant. 6; L. ant. =+4 R. post. +5; L. post.= - 7. and either foot constitute weak leads (unwirksame Anordnung). Upon the dog (and upon the horse) it was shown that the transverse effect was relatively small, and that the right and left lateral effects were relatively large and of equal size'. For the purpose of this demonstration where movements of a capillary columtn of mercury were projected upon a screen, direction of movement was noted from the second and most obvious portion of the double movement that accompanied each beat; but the principal fact upon which attention was concentrated was the comparative size of movement in the several leads; and in this connection it was clear that the less oblique hearts of a dog and of a horse gave effects differing in character from those observed with the more oblique heart of a man. In the case of quadrupeds "superior"=-"anterior" and "inferior"= "posterior." Strong leads are: the left superior or anterior and the right inferior or posterior. Weak leads are: the right superior or anterior and the left inferior or posterior.

9 S.OCIETY, DEC. 13, I have of course learned from further observation of all sorts of hearts that in man the ventricular spike is frequently of reversed direction in the weak 'leads (R. sup. and L. inf.) and sometimes of reversed direction in the transverse lead'. But as regards dog and horse I have arrived at no such definite results, for lack of any sufficient series of observations upon trained animals of known age and health. I have indeed a good many sporadic observations of various leads taken on dogs and horses to demonstrate the "electrocardiograms" of these animals, but in only a few cases a series of the five leads from which the position of the current-axis can be determined. Reviewing the few five-lead records I possess of dogs and horses I find no record of the dog in which the spike of the weak leads is of reversed direction. xxxiii But in one carefully taken series of a horse I find reversed systolic spikes in the right anterior and left posterior leads. Taking their values along with the corresponding values of the left anterior and right posterior spikes, and applying to them the formula for the cardiac angle of the human subject, we obtain the following results: Ant. tan =4+6=_5; sup. a=1010 Post. tan 5+7 a=25-1=-12; post. a=95'. The diagram of this horse exhibits a very transverse or wide-angled current-axis approximating to what I have described for man as characteristic of a horizontal or " soft" heart. In harmony with this character the transverse lead in this animal is particularly " strong," contrasting in this respect with that of some of the horses studied by Norr and Kahn, as well as from that exhibited by me in Berlin in 1889; in all these animals the transverse was a weak lead, and the right and left posterior leads were strong and approximately equal. The current-axis in these cases must have been very longitudinal or narrow-angled. 1 Apart from the reversal that is due to situs vi8cerum inversu8. With this state - of which two cases were described at the Berlin meeting-the normal diagram is as viewed in a mirror, normally " weak " leads, R. sup. and L. inf., are " strong," and normally "s trong " leads, L. sup. and R. inf., are " weak." The transverse record alone is reversed. These facts have been more or less completely rediscovered by several independent observers since their first publication in The latest description is by Samo jloff in Pfluger's Archiv, July 13, 1913, pp. 197 et seq., vol. clm.

10 xxxiv PROCEEDINGS OF THE PHYSIOLOGICAL Electrocardiogram of horse. By A. D. WALLER. In the case of the human electrocardiogram there is a close correspondence in time between the first and second ventricular peaks R and T and the first and second sounds, or the beginning and end of the ventricular systole. In the case of the horse, judging from the records of Kahn (Pfliger's Archiv, CLIV. fig. 5, p. 8) the end of the second peak appears to precede the end of ventricular systole by a considerable interval. The figure given by Kahn to correlate the electrocardiogram with the pressure changes after Chauveau and Marey, does not coincide with my own view of the matter. I have made the same correlation, and find that in the horse, as in man, the first and second ventricular waves VI and VII (or according to the now prevalent rubric R and T) correspond very nearly with the beginning and end of the ventricular systole, or with the first and second sounds. I read my own electrocardiograms of the horse as giving a duration of systole= 0-4 sec. (at a pulse frequency of 50), a value which corresponds with the duration originally given by Chau veau for the ventricular pressure curve. Whereas Kahn gives this systolic value as 0,5 to 0'6 sec. at a pulse frequency of 54 (his K. Ekg. he gives= 0 49 to 0-62 sec., although his figures 3 and 4 on pp. 5 and 6 exhibit a value = 0-42). In the accompanying figure, taken from a class-diagram, I have indicated the time-relations between the electrical and the mechanical (intra-ventricular pressure) events, and the sounds. I find that in the horse as in man, the length of systole is to be measured from the beginning of VI to the end of VI, which correspond with the beginnilng and end of the ventricular systole. In man at the pulse-frequency 72., the durationl 'Oystole so measured= 0-33 or *rd sec.; in the horse at the pulse-frequency 50 it comes out =0-4 or ts sc

11 SOCIETY, DEC. 13, XXXV Direct determination of the percentage saturation of arterial blood with oxygen in a normal person. By A. COOKE, F.R.C.S. and J. BARCROFT. In a case of? intestinal ulceration accompanied by severe annmia it was thought desirable to perform the operation of transfusion of blood into the patient from his sister. The transfusion was made from the radial artery (by the insertion of a cannula into that vessel) into the basilic vein of the patient. The insertion of a cannula into the radial artery of a healthy person gave an opportunity for the collection of some arterial blood, uncontaminated either with air or ancesthetics for analysis. The blood was received into a tube of narrow bore, about the size of an ordinary 1 c.c. pipette, fitted with a tap at each end. In the tube was placed a little hirudin and a globule of mercury to mix the hirudin and the blood. The analysis was performed by the differential blood gas apparatus. The blood proved to be 940/0 saturated with oxygen, after due correction had been made for the exchange of gases in a state of physical solution under the conditions of temperature and pressure which obtained in the body and in the apparatus.