Influence of breast-feeding on the production of cytokines.
OBJECTIVE
Recently, we reported increases in the production of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and IL-4 during the postpartum period. The present study was undertaken to investigate whether these increases might be explained by increased prolactin while breast-feeding.


METHODS
Whole blood from 41 women who were breast-feeding, 13 women not breast-feeding, and 31 healthy non-pregnant women was stimulated with phorbol 12-myristate 13-acetate and ionomycin, and the levels of cytokines in the supernatant were measured by enzyme-linked immunosorbent assay. Their serum levels of prolactin were measured by enzyme immunoassay.


RESULTS
Increases in IFN-gamma, IL-2, IL-4, and IL-10 production were observed in women who were breast-feeding but not in women who were not breast-feeding. Serum levels of prolactin correlated with the levels of IFN-gamma in culture supernatant.


CONCLUSIONS
These results suggest that breast-feeding induces production of cytokines and that IFN-gamma production is enhanced by physiological concentrations of prolactin.
Shimaoka
Y
Y
Department of Laboratory Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
Hidaka
Y
Y
Tada
H
H
Takeoka
K
K
Morimoto
Y
Y
Amino
N
N
D001942:Breast Feeding; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D011388:Prolactin / Q000097:blood
D016207:Cytokines; D007376:Interleukin-2; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma; D011388:Prolactin