Unbound vascular endothelial growth factor and its receptors in breast, human milk, and newborn intestine.
BACKGROUND
Human milk, rich in cytokines, may contain the potent permeability- and angiogenesis-promoting agent vascular endothelial growth factor (VEGF).


OBJECTIVE
We wanted to study whether free or bound VEGF is present in human milk and whether it and its receptors (VEGFR-1 and -2) are expressed in lactating breast or newborn intestinal tissue.


METHODS
The study had a longitudinal design with collection of human milk from healthy (n = 32) and diabetic (n = 5) women at 2, 7, and 30 d postpartum. Milk was analyzed for VEGF by enzyme-linked immunosorbent assay along with plasma samples collected 2 d postpartum. Immunohistochemistry was used to localize VEGF and its receptors in lactating breast and newborn intestine. Gel filtration with radiolabeled VEGF was performed to study whether human milk contains VEGF binding proteins.


RESULTS
Human milk VEGF concentrations in healthy (76 +/- 19 microg/L, x +/- SD) and diabetic (75 +/- 25 microg/L) women did not differ at 2, 7 (23 +/- 7 and 27 +/- 8 microg/L, respectively), or 30 d (14 +/- 5 and 17 +/- 7 microg/L, respectively) postpartum. VEGF was undetectable in all but 3 plasma samples. Human milk was free of VEGF binding proteins. VEGFR-1 and -2 immunoreactivity was seen in the glandular epithelial cells of the newborn intestine and lactating breast, whereas VEGF was present only in breast glandular epithelium.


CONCLUSIONS
The high concentrations of VEGF in human milk, especially colostrum, are not affected by maternal diabetes and may play a role in newborn nutrition.
Vuorela
P
P
Departments of Obstetrics and Gynecology and Pediatrics, Helsinki University Central Hospital, and the Department of Pathology, Haartman Institute, Helsinki, Finland. piia.vuorela@kolumbus.fi
Andersson
S
S
Carpén
O
O
Ylikorkala
O
O
Halmesmäki
E
E
D001940:Breast / Q000737:chemistry*; D002850:Chromatography, Gel; D003126:Colostrum / Q000737:chemistry; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000032:analysis* / Q000097:blood; D004848:Epithelium / Q000737:chemistry; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D007422:Intestines / Q000737:chemistry*; D007774:Lactation; D008222:Lymphokines / Q000032:analysis* / Q000097:blood; D008895:Milk, Human / Q000737:chemistry*; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis*; D017978:Receptors, Growth Factor / Q000032:analysis*; D040262:Receptors, Vascular Endothelial Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D017978:Receptors, Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor