Zoology

"Substances Which Cannot Be Absent Without Injury"

Gerrit GRIJNS. From Over polyneuritis gallinarum, in Geneeskundig tijdschrift voor Nederlandsch-Indië, vol. 41, p. 3, 1901; tr. "under the direction of the Working Committee" in Prof. Dr. G. Grijns’ researches on vitamins 1900–1911, Gorinchen, 1935; with the permission of J. Noorduijn en Zoon N.V., publisher.

In judging the suitability of a food, we have not finished when we have determined the quantity of albumen (which is generally only calculated from the determination of nitrogen), fat, carbohydrates and salts, even when we have applied the corrections for the digestibility. We can indeed calculate from this whether a balance of nitrogen will be possible with it and whether the work which must be performed both internally and externally, can be obtained from it, but not whether permanent health is possible.

The determinations of metabolism made hitherto have taught us to understand the metabolism of the whole human being or of the whole animal, but, as the metabolism of the muscles and of the large glands is so great in comparison with that of other organs, the influence of these organs comes within the observation errors and within the individual differences of the metabolism of the former. This is the reason why we, in spite of the large number of tests of all kinds of foods, know practically nothing about the metabolism of the nervous system, while we only assume the metabolism in the peripheral nerves by analogy.

Most of the experiments on the balance of nitrogen were only continued for a few days, so that only an unchanged body weight and balance of nitrogen prove that the great metabolism (as I shall call it) was satisfied, but this did not show that the requirements of the more modest organs were met.

Not only are there a large number of different albuminoid substances, fats, etc., but there are also a number of composite substances, which no doubt play an important part, although their action is not fully explained. We need only remember the peculiar fact that scurvy, which usually develops from the lack of fresh food, which sometimes occurs on long sea voyages, is usually cured when the patients can again obtain fresh meat and fresh greens.

We must therefore bear in mind that still unknown substances may be in question.

There were two ways of gaining an insight into the matter. We might try to isolate different substances from the silver skin or we might seek for other food-stuffs which had the same effect and try to get at the truth by comparative analyses.

Experiments were made in both directions.

For the first series it had to be ascertained how much silver skin or fine rice bran (dedek) was necessary in order to prevent the neuritis, if only polished rice was given besides. Fowls were fed with boiled polished rice, to which carefully weighed quantities of dedek were added. Eijkman had already stated that fowls could be kept healthy with rice and fine rice bran and even be cured if already ill. He expressly states that the quantity of silver skin must not be too small.

INTRODUCTION

When, in July 1896, the Government commissioned me to investigate the physiological and pharmacological properties of the tannin contained in red rice, and possibly other constituents of this kind of rice which might require consideration in relation particularly to beri-beri, Dr. Eijkman, who had not yet published the results of his most recent experiments on fowl-polyneuritis, had left for Europe and Dr. Vorderman was on his tour of enquiry through Java and Madura. Moreover, a few days after my return from Atjeh, Mr. Roll, deputy director of this Institute, was absent from Batavia for a considerable period owing to an epizootic at Tegal. I had, therefore, to proceed on what I learned from letters on the subject and from information obtained at the laboratory for pathological anatomy and bacteriology.

It is, therefore, not surprising that at the beginning of my investigation I could not immediately utilise all that Dr. Eijkman’s researches on the connection between polyneuritis and diet had brought to light.

The above-mentioned tannin had not yet been isolated from the silver skin, and I was, therefore, faced with the question from what point of view I should approach the problem.

A personal interview with the Director of Education, Religion and Industry had convinced me that it was not the intention of the Government that I should keep strictly to the letter of the commission, but that my investigation should aim, by discovering the connection between diet and polyneuritis and by extending the results obtained by Dr. Eijkman, to get an insight into the etiology of neuritis, which would make it possible to indicate the direction in which the rational control of neuritis should be sought.

At the same time it was to be ascertained how far the pigment found in the red rice might be considered as a curative or a preventive remedy against beri-beri.

It seemed to me that I should not confine myself to the red pigment, but should keep the whole silver skin in view, for it would be a strange chance if it were just the substance most easily chemically demonstrated which was the one we were seeking.

Besides, Mr. Roll had told me that according to the last, then still unpublished experiments of Dr. Eijkman, not only red, but all semi-decorticated rice prevented polyneuritis in fowls.

There were two ways open to me: either to continue the study of polyneuritis gallinarum or to carry out feeding experiments on a large scale in prisons or army corps where there was a great deal of beri-beri.

As to the latter, it was only rational to await the results of Dr. Vorderman’s enquiry and to make proposals in connection with it. Besides, it was obvious that such experiments would be difficult and expensive, so that I resolved first to try and get more light on the connection between polyneuritis of fowls and diet.

I have now continued these fowl experiments almost uninterruptedly for more than three years, and think I have made sufficient progress for it to be worth while publishing the results already obtained.

Five cocks (Nos. 86–91) were fed for 16 days with boiled polished white rice.

One had distinct symptoms of polyneuritis, of which it died on the 20th day (No. 89). Another (No. 90) showed slight paresis and cyanosis. The three others had pale combs.

After the sixteenth day, at first 8 and later 10 grammes of fine dedek (rice bran) was mixed with their rice.

Of these, No. 87 died at the end of 2 months from a croupous inflammation of the throat and eye. No degeneration was found in the nerves. No. 90 progressed at first, but died after 72 days from a general infectious disease. Only a few remains of earlier degeneration were found in the nerves.

No. 88 had no symptom of neuritis after 5 months, but was suffering from a skin disease, accompanied later by a croupous affection of the throat, nose and eye, and died 6 months after the beginning of the experiment. A few old degenerated bundles were found in the nerves.

No. 86 was healthy at first, but after 3 months showed a diminution of muscular strength. The quantity of dedek given daily was therefore raised to 12 gr. when the paralytic symptoms disappeared. After 7 months it died from croupous inflammation of the throat and eye and some degenerated bundles were found in its nerves. ...

RECAPITULATION

If we examine the foregoing results, we come to the following considerations.

We had in polyneuritis gallinarum, as described by Eijkman, a disease which, both in its clinical symptoms and in the changes which it produces in the peripheral nervous system, very much resembles beri-beri. The cause of both was hitherto unknown.

There was one remarkable difference that, while a very dose, direct connection appeared to exist between polyneuritis of fowls and the nature of the food, beri-beri could not be so directly connected with the feeding; indeed except for the results of Vorderman’s enquiry, there were not many observations which appeared to support this connection.

Various foods were held responsible for causing beri-beri, but there was much lacking in the arguments for these assertions and even Vorderman’s enquiry was disputed.

It seems to me that through my results, the analogy between fowl neuritis and beri-beri is much greater than it appeared to be at first; and this strengthens my conviction that the further study of the etiology of this disease will open up new aspects of that of beri-beri.

From the fact that polyneuritis also occurred among fowls when fed with gaba and foods which do not contain any carbohydrates, it appears that here also no direct connection exists between the occurrence of the disease and food.

I believe that the results of tests with sterilised and boiled meat entitle us to exclude a harmful constituent present in the food. The comparison of the results with sterilised and non-sterilised katjang hidjoe and polished rice also support this and the more so, because, owing to the development of polyneuritis after feeding with potato flour and milk sugar, the reasons were removed for assuming the presence of a specific harmful substance in certain sorts of starch (one might consider this as a previously formed poison or assume that during digestion a poison has been formed from it).

In my opinion an explanation of the peculiar symptoms which occur in the disease in question can be sought in but two directions. Either we can presume a deficiency, a partial starvation, or we can imagine that there is an agent distributed in nature, which exercises a degenerative influence on the nerves and that it depends on the nature of the food, whether the peripheral nervous system has enough power of resistance to get the better of this influence. In the latter case, it is most likely that the harmful agent is a microorganism.

That the condition of nourishment of the tissues has a great influence on their resistant power against infectious organisms is already well known; one has only to think of the development of abscesses in tissues whose condition of nourishment (owing to previous ischaemia etc.) has suffered from the infection of staphylococci into the blood. That chemical substances can also modify the susceptibility for certain infectious diseases, appears from the tests of Charin, Guillemonot and Levaditi, who found that by repeated injections of organic acids (oxalic, lactic and citric acids) the power of resistance of animals to bacterium pyocyaneum was lessened, while injections with sulphuric soda, phosphoric soda and potash and with salt had the contrary effect.

The negative result of feeding tests by Eijkman in the Zoological Gardens at Amsterdam supported such a theory. However this author informed me in a private communication that in later tests with compulsory rice feeding he saw polyneuritis develop. So the possibility of an infection is not excluded, but the principal fact in its favour is removed.

There is also much to be said for the other explanation that we have to do with a partial starvation.

I mentioned in Section 4 that we know very little of the metabolism of the peripheral nervous system. From the comparatively small number of blood vessels in the nerves, we may however assume a low metabolism. If for the maintenance of the peripheral nervous system, a certain substance or group of substances is indispensable which are immaterial for the metabolism of the muscles, then it may be assumed that very little of them is necessary. We cannot be surprised if such substances have hitherto escaped observation i.e. chemical analysis. (I only need to remind you of the fact, that we do not yet know the form in which compounds of phosphorus and calcium, must be absorbed in our body in order to benefit us, to show how great are the deficiences in our knowledge of this matter.)

When therefore in certain foods the substances indispensable for the nervous system are lacking or are present in insufficient quantity, in the first place any reserve supply, which is present either in tile nerve itself or in the blood or in some other organ, will be used up. When this occurs, disturbances will develop, just as in albumen starvation the circulating albumen is used up first and then that of the organs. Therefore from the time the deficiency begins, a certain time must elapse before symptoms set in in the nervous system; there will be a sort of incubation period. This will be the longer, the smaller the deficiency of the nutritive substances, which are indispensable for the nerve, in the food taken.

If besides these "protective substances," as I have named the still unknown compounds which I have mentioned now and then without any prejudice, albumen is also withheld, which is the case with an absolute diet, then, as is wellknown, the albumen indispensable for metabolism is drawn from the organs, especially the muscles. As the muscular substance also possesses protective qualities, it is probable that with the albumen from the muscles enough of the substances are liberated and become available for the nerves, to prevent polyneuritis.

This is a simple explanation why, when there is absolute starvation no polyneuritis is observed.

I admit that there is a third possibility. One may assume the presence of a nerve-degenerating poison, which is able to originate in the intestinal canal and of an antidote, which neutralises the poison or, at any rate, its action. The absence of this antidote would then open the door for the development of polyneuritis and in that case, the development of the disease would depend on the occurrence or non occurrence of the poison. This theory appears to give an easy explanation of the fact that with the same diet, some fowls fall ill and others do not.

However, my investigations have raised doubts about this theory. As the development of polyneuritis does not appear to be connected with the presence of starch or carbohydrates, but also occurred with an exclusively albuminoid diet, it is difficult to accept the hypothesis that with some foods, special conditions are present in the intestinal canal, favourable to the development of certain micro-organisms, which produce a nerve poison, as the conditions for the growth of these organisms would always be present. The acceptance of such a widespread antidote also seems rather rash, as we find no example of this in the case of the known antitoxins.

Besides, the above-mentioned explanation is not as simple as it looks. Why does the poison develop in some of the fowls fed in the same place and in the same way, and not in others. And we cannot thus escape the necessity of taking into account individual differences, of which we have no explanation and which we generally call predisposition. If, however, we take individual differences into account, we can, if we assume partial starvation, very easily understand why, with the same food, one fowl falls ill and another does not. We know that metabolism shows quantitative differences in individuals of the same kind. We see that one person needs a much larger quantity of food than another to maintain his physical equilibrium, while doing the same work, than another. We see one child pining away with a certain diet, while another grows and flourishes. If therefore the total metabolism shows imporrant quantitative and perhaps small qualitative differences, there is no reason why, in the separate tissues which together furnish the total metabolism, we should not assume individual quantitative differences. And if we are justified in doing this, there is nothing absurd in the supposition that a food which contains just enough of the still unknown nerve nutritive substances for one fowl contains too little for another.

Whether we envisage the influence of diet on the development of polyneuritis gallinarum as a change in the predisposition or as a purely nutritive disturbance owing to partial starvation, we always come to the following conclusion:

There occur in various natural foods, substances, which cannot be absent without serious injury to the peripheral nervous system. The distribution of these substances in the different food-stuffs is very unequal. Of those examined, phaseolus radiatus and ca janus indicus were the richest, and polished rice the poorest in these substances.

The separation of these substances meets with the difficulty that they are so easily disintegrated. This disintegration, which takes place in a damp warm place, shows that they are very complex substances. They cannot be replaced by simple chemical compounds.