Soluble vascular endothelial growth factor receptor 1 in human breast milk

Vascular endothelial growth factor (VEGF) is a potent proangiogenic protein that activates VEGF receptor (VEGFR-1, VEGFR-2) tyrosine kinases expressed by vascular endothelial cells. A soluble truncated form of VEGFR-1 (sVEGFR-1) binds to VEGF as strongly as full-length VEGFR-1 and inhibits VEGF activity. sVEGFR-1 can be detected in mouse and human plasma but in human milk sVEGFR-1 has not been described previously.

We measured sVEGFR-1 and VEGF in human milk and examined how the concentration varied with gestational age and the duration of lactation after birth. Human milk samples were collected from 29 mothers of preterm (<37 weeks) and from 29 mothers of term (>38 weeks) infants at days 3, 7 and 28 postpartum.

The sVEGFR-1 and VEGF concentrations were greater in the human milk of mothers of preterm compared to term neonates (p < 0.05). Furthermore, the concentrations of sVEGFR-1 and VEGF were decreasing during postpartum days 3, 7 and 28. The concentration of sVEGFR-1 showed a positive correlation with the concentration of VEGF in human milk (r = 0.479 and p < 0.001).

sVEGFR-1 is present in human milk and has a role in angiogenesis.