Substances In Human Milk Research Articles

Within-Day Variation of Taurine and Other Nitrogen Substances in Human Milk

Milk samples were collected from seven mothers during their 8th wk of lactation. On the day of collection one breast was completely emptied at 600, 1000, 1400, 1800, and 2200h. Concentrations of total nitrogen, protein nitrogen, urea nitrogen, and free amino acids (taurine and glutamine plus glutamic acid) were determined. Concentrations of these nitrogen substances in the milk differed significantly among women but were relatively constant during the day. The mean concentrations of these substances per 100ml of milk were total nitrogen, .189g; protein nitrogen, .145g; urea nitrogen, .020g; taurine 34.9 μmol; glutamine plus glutamic acid, 200.0 μmol.

Levels of human milk-specific immunoglobulin A antibodies during lactation.

The secretory immunoglubulin of the Immunoglobulin A class (SIgA) appears to be the most important of the soluble substances in human milk in terms of protection against diarrheal disease in breastfed infants. Longterm follow-up studies of milk antibodies in human milk have indicated that the concentration of IgA specific antibodies fluctuates during lactation with the most dramatic changes noted among women living in areas where hygienic conditions are poor. Total SIgA concentration and IgA-specific antibodies against Escherichia coli labile toxin (EcLT) Shigella B6 somatic antigen (SB6) and rotaviruses were determined in 20 lactating mothers from a rural area in Guatemala over a 16-week period. The mean concentration of SIgA was highest at the beginning of lactation and reached a plateau at 2-3 weeks postpartum. The levels of specific antibodies against EcLT SB6 and rotaviruses fluctuated in each of the women independently of total SIgA concentration and of one another. In 90% of subjects at least 1 of the specific antibodies reached nondetectable levels at some point in the study. These fluctuations may be related to the presence of homologous antigens in the maternal intestine. It is suggested that the presence of the antigen in the intestine of the mother inhibits the migration of primed IgA committed lymphocytes from the intestine to the mammary gland. This phenomenon has important practical implications. If a lactopositive breastfeeding mother becomes infected by an intestinal pathogen the levels of her milk antibodies will reach very low levels. In turn if her infant is infected by that pathogen there is an increased likelihood that the infection will result in diarrhea.

トロンボキサン産生系を介さないヒト乳中の血小板凝集物質

The effect of a substanse in human milk on the several metabolic reaction in platelet and a few characterization of the substance were studied in this paper. The amount of thromboxane B2 produced after the aggregation did not differ from that of resting platelets. The activity of adenylate cyclase in platelet received the non competitive inhibition by the substance. Although the activity of cAMP phosphodiesterase was also inhibited by the substance, the inhibitory degree of the substance on the activity was less than that on the activity of adenylate cyclase. The platelet aggregating activity of the substance was lost by the heating at 100°C for 5min. and the treatment by trypsin and N-ethylmaleimide.It was elucidated that platelet aggregating substance in human milk induce the aggregation by the mechanism unrelating to production of thromboxane B2 and is a high molecular protein, which need the SH group for occurence of the aggregating activity.

Hormonal Substances in Human Milk, Cow's Milk and Dairy Products

Hormone-like substances are normal constituents of cow's and human milk. Progesterone has been quantified in cow's milk and dairy products with butter containing a high value of 300 ng/g. Estrogenic substances have been detected in cow's and human milk but literature values are sparse or tend to vary widely possibly because quanitative methods available lacked specificity and sensitivity. Pregnanediol is rather unique to human milk and its presence in elevated levels has been associated with prolonged neonatal jaundice of nursing infants. The concentration of this steroid in affected mother's milk appears to be in the range of 150–450 ng/ml. 17-Ketosteroids may be present in cow's and human milk but here again limited literature values vary widely. Corticoids have been reported in cow's milk at a concentration of 3.1–3.7 ng/ml. Thyroxine and triiodothyronine are present in human milk but practically undetectable in cow's milk. Prostaglandins (PGF2α) have been determined to be present in cow's milk at concentrations between 0.1 to 0.4 ng/ml.

Periodic Occurrence of Methyl Glyoxal=like Substance in Human Milk and Periodic Weakening of Arakawa's Reaction. Influence of Menstruation upon Human Milk

In a case of a healthy lactating woman, we had been examining the influence of a frequent administration of vitamin C in a large amount upon Arakawa's reaction of her milk.. It did not change in spite of a possibility that it might change the reaction from positive to negative in vivo too (as is the case in vitro). But suddenly it happened that the reaction became negative, to become again positive after a lapse of several days. We were able to identify a large amount of the methyl glyoxal like substance in her milk. During a long observation, such an incidence occurred three times with about one month's cycle. The second time she had a manifest menstruation and it became clear that she had a manifest menstruation once, and an occult menstruation the two other times. In the case of an investigation into Arakawa's reaction of a lactating woman with positive reaction, we must take'into consideration the influence of an occult or manifest menstruation. Suppose we have given a large amount of ascorbic acid to her, just before a coming menstruation, then, we might attribute the negative Arakawa's reaction, which will occur due to the menstruation, to an administration of vitamin C, especially because this will, as this did really in our case, increase very much in the milk. Isono, one of us, proved that even a large amount of the vitamin C like substance in human milk cannot make Arakawa's reaction negative in a rather large number of cases. As to the cause of negative Arakawa's reaction, it may be. due to a hypofunction of the liver which will be caused by the ovarial function at menstruation.

Arakawa's Reaction and Vitamin C Content of Human Milk. Part 1. The Influence of Vitamin C upon Arakawa's Reaction

In the present paper I have made an investigation into the influence of vitamin C upon Arakawa's reaction with the following results:- 1. An oral or parenteral administration of vitamin C in a large amount did not change Arakawa's reaction remarkably. 2. The amount required of vitamin C to make the urine of 4 mgrms. % content in the vitamin was in the case of strong Arakawa's reaction 1.4-1.6 grms. and 1.2-1.4 grins. in the case of the negative re-action of the intensity 5'(-). 3. In such cases with a certain daily fluctuation of Arakawa's reaction, the fluctuation had nothing to do with vitamin C, and in such cases with a daily change of the vitamin content in milk, the change had no or scarcely any connection with Arakawa's reaction. 4. In spite of almost the same diet, human milk with Arakawa's reaction of the intensity 5'(-) was of a larger content in vitamin C (like substance) than milk positive to the reaction. 5. There was no remarkable difference between the Arakawa reaction and the amount of milk secretion, “rich” or “poor” secretion taking the word of the mothers themselves. 6. The amount of vitamin C necessary to make Arakawa-positive milk Arakawa negative in vitro was very much larger than had hitherto been reported in literature. 7. The trial to make the C-vitamin like substance in human milk disappear by force of Arakawa's reagent No. 3 was unable to intensify the Arakawa reaction remarkably.

Arakawa's Reaction and Vitamin C Content of Human Milk

I investigated the oxidation of the vitamin C like substance in human milk and that of the ascorbic acid by means of the Arakawa Reagent III and knew that peroxide and guaiacol (or guaiacol-like substance) are necessary for this oxidation. Further, I knew that an addition of the reagent can oxidize a large amount of ascorbic acid, and was able to differentiate between human milk with AR 5' (-)* and Arakawa-positive milk made Arakawa-negative by ascorbic acid.

Arakawa's Reaction and Content of Methyl Glyoxal=like Substance of Human Milk

Takamatsu of our Laboratory investigated methyl glyoxal like substance in human milk and concluded that the substance is rich in Arakawa-negative milk and poor in Arakawa-positive milk. His materials were only 35 cases. I further studied the relation in 176 cases and was able to confirm his result. Besides, I observed the relation from the seasonal point of view and, by way of appendix, from the view of diseases of infants.

Arakawa's Reaction and Vitamin C Content of Human Milk

My own investigation into the influence of the peroxidase in human and cow's milk upon the vitamin C like substance and the ascorbic acid will show the following facts. 1. Human milk has the anti-oxidative function, which is stronger in Arakawa-negative milk than in Arakawa-positive milk. 2. Human milk will oxidize the vitamin C like substance in human milk and synthetic ascorbic acid in cooperation with Arakawa's Reagent III. Though it is a question whether this is due to peroxidase in it, the effect of the oxidation is much stronger in Arakawapositive milk than in Arakawa-negative milk. Such an effect is not seen in heated human milk. 3. The peroxidase concentrate prepared from cow's milk has the effect of converting into the reversibly oxidized form the vitamin C like substance and ascorbic acid. 4. The reversible oxidation capacity is not influenced by the anti-oxidative function of human milk, of heated human milk and of NaCl. 5. The reversibly oxidation capacity of human milk with AR 5' (-) plus Arakawa's Reagent III is not equal among different milk specimens, though there is a definite limit of fluctuation. 6. The reversibly oxidized form of vitamin C like substance is present in a large amount in Arakawa-positive milk, but it can be identified in Arakawa-negative milk too. 7. The difference of the content of the reversibly oxidized form in human milk has its cause probably in mammary glands themselves. 8. The difference of the vitamin C like substance and that of Arakawa's reaction are concomitant, though one of these is not successive to the other.

Variation of the Amount of Methyl Glyoxal like Substance in Human Milk on Administration of Vitamin B<sub>1</sub> without or with Yakriton, and on Antisyphilitic Treatment; Initial and Temporary Exacerbation of Arakawa's Reaction on Administration of Vitamin B<sub>1</sub>

Variation of the Amount of Methyl Glyoxal like Substance in Human Milk on Administration of Vitamin B<sub>1</sub> without or with Yakriton, and on Antisyphilitic Treatment; Initial and Temporary Exacerbation of Arakawa's Reaction on Administration of Vitamin B<sub>1</sub>