| Time. | Number white corpuscles per cubic millimeter blood. |
|---|---|
| 9 A. M. | 8,689 |
| 9 A. M. | 100 grams meat fed. |
| 10 A. M. | 16,685 |
| 11 A. M. | 17,296 |
| 5 P. M. | 7,256 |
| Maximal increase, 99 per cent. | |
About thirty distinct experiments were tried on ten different animals, with only two or three negative results to fifty positive ones. The results, taken collectively, plainly indicate that the increase in the number of leucocytes in the circulating blood, after the ingestion of food, is very marked, the maximal increase being 146 per cent., while the average increase amounted to 78 per cent. This, as Pohl states, would indicate for the total content of blood in an animal an increase in some cases of 1,000,000,000 of leucocytes. Control experiments showed that, normally, there were only comparatively small variations in the content of leucocytes in the blood, from hour to hour, in the absence of food. It is to be further observed that this marked increase in the number of white corpuscles in the circulating blood, after the ingestion of food, usually reaches its maximum in the third hour, viz.: at a time when digestion would most probably have reached its height, no noticeable change being usually observed before the end of the first hour after the taking of food. Evidently, some transformation-products of the ingested food must be formed before leucocytosis becomes marked. The return to the normal number of leucocytes shows no regularity; in some cases being very gradual, in others quite rapid.
This marked action of food in increasing the number of leucocytes in the circulating blood, naturally raises the question whether all varieties of food possess this power, or whether it is limited to some one or more individual food-stuffs. In attempting to answer this question, Pohl tried a large number of experiments, the results of which afforded proof that neither water, salts, fats, carbohydrates, or even meat extracts, are able to materially affect the number of leucocytes in the blood. Proteid-containing foods, on the other hand, such as meat, Witte’s peptone, and gelatin peptone quickly raise the content of white blood corpuscles to a marked degree. Somewhat noticeable was the result obtained on feeding wheat bread. This food-stuff, in spite of its fairly large content of proteid matter, failed to exert any influence on the number of leucocytes in the blood, and in conformity with this result it was found that in herbivorous animals there was an utter lack of anything approaching a digestive leucocytosis, even after protracted fasting.
In attempting to explain the cause of this increase in the number of leucocytes in the circulating blood, after the ingestion of proteid food, we are at once confronted with the possibility of this apparent increase being relative rather than absolute; as possibly due to a loss of water from the blood, incidental to the marked outpouring of digestive juices accompanying digestive proteolosis. For this view, however, there is very little support. In the first place, the blood would need to become very much thickened by loss of water to account for the increased number of leucocytes observed in the experiments. Furthermore, we know that the outpouring of watery secretions into the intestine during digestion is accompanied by an absorptive current in the opposite direction, which would tend to counteract any tendency towards concentration of the blood, and, indeed, might lead in many cases to a direct dilution of this fluid. Again, if the increase in the number of white corpuscles is to be explained in this manner, there should be a corresponding increase in the number of red blood corpuscles. As a matter of fact, Pohl’s results show that those conditions of diet tending to increase the number of white blood corpuscles are without any noticeable effect on the red corpuscles. Abstraction of water can not, therefore, be the cause of the large number of leucocytes contained in the blood after a proteid diet. Much more plausible is the view that the increase is due to a more rapid transference of the corpuscles from their point of origin, viz.: from the intestine and from the lymph glands of the mesentery, to the blood. In other words, it seems probable that digestive proteolysis in the stomach and intestine is followed or accompanied by a rapid production of new cells in the lymph spaces surrounding the intestine. If this view is correct, there should be a much larger number of leucocytes in the blood and lymph flowing from the intestine, in an animal in full digestion, than in the arterial blood coming to the intestinal tract. That such is the case is shown by the following experiment taken from the many reported by Pohl:
Dog weighing 3,330 Grams, in Good Digestion. A.M. 8.50. Blood from skin contained 8,330 white corpuscles in cubic mm. 9.10. Blood from skin contained 9,618 white corpuscles in cubic mm. 120 grams meat and 20 c. c. water fed. 10.40. Blood from the skin contained 15,092 white corpuscles in cubic mm. 10.55. Body opened, several loops made with the small intestine, and blood withdrawn from vein and artery without any great loss of blood.
The facts would thus seem to warrant the assertion that, as a rule, the venous blood flowing from the intestinal tract of an animal, fed on a rich proteid diet, contains a much larger number of leucocytes than the arterial blood flowing to the intestine; although, if space permitted, we might instance certain occasional exceptions due to various causes, which, however, do not reflect against the view that there is a marked production of leucocytes in the lymph spaces surrounding the intestine, and in the lymph glands of the mesentery, as a normal accompaniment to digestive proteolysis.
Taking into account all of the circumstances attending the circulation of the blood through the abdominal organs, especially the rate of flow, and remembering the great increase in the number of leucocytes contained in the blood during the several hours attending digestive proteolysis, it is plain that a comparatively large amount of proteid matter must be transferred from the intestine to the blood in the bodies of the white corpuscles so abundantly produced in the lymph glands, etc., during proteid digestion. Indeed, Pohl calculates, on the basis of his own and the observations of others, that in the case of an animal weighing 5 kilograms, and fed with 100 grams of fresh beef, containing 20 grams of proteid matter, the entire amount of albumin required to supply the loss incidental to the normal physiological processes of the body could be absorbed into the circulation from the intestine in the form of leucocytes, assuming a digestive period of six hours. Moreover, the evidence acquired from Pohl’s experiments of the enormous production of new cells in the intestinal walls during the height of digestion renders such a theory of the transference of proteid matter from the alimentary tract to the tissues and fluids of the body quite plausible. At the end of twenty-four hours the leucocytes have fallen back to their normal number, having presumably been broken down in the blood-plasma or dissolved in the tissues and organs, thus giving up the proteid matter, of which they are composed, for the general nourishment of the body. Obviously, we can not admit that all the proteid matter of the food is absorbed in the form of leucocytes, for, as we know, some at least of the proteid food ingested is carried beyond the peptone stage, either through the action of trypsin, or through the action of the organized germs in the intestine, but we can certainly accept the views so admirably worked out by Pohl, in so far as they indicate one way in which proteid matter may pass from the intestine into the blood, after having undergone a preliminary transformation in the alimentary tract into primary albumoses and peptone. Again, if Pohl’s views are correct, we see that the proteid foods are quickly transformed into organized material in the body of the lymph cell prior to their absorption into the blood, a view which is in harmony with the long-known fact that peptone and other products of digestion can not be detected, in any quantity, at least, in the blood of the portal vein, even after the ingestion of a diet rich in proteids. As has been frequently stated in the past, the products of proteolytic action are transformed in the very act of absorption, presumably through the activity of the epithelial cells of the villi, and we may now assume, in the light of Pohl’s results, that this transformation may be due in part, at least, to the upbuilding of the ordinary products of digestion into the living protoplasm of the white corpuscles in the intestinal walls, and in this form as organized albumin circulated through the body.
Editorial in Dietetic and Hygienic Gazette, November, 1893.
Book Notices.
An American Text-Book of Gynecology, Medical and Surgical, for the Use of Students and Practitioners. Edited by J. M. Baldy, M. D., assisted by a corps of Nine Contributors. Cloth, 8 vo., pp. 713. 360 illustrations and 37 colored and half tone plates. Philadelphia: W. B. Saunders, 1894. (Sold by Subscriptions only; Price, $6.00).