Prostaglandins in human milk.

Levels of prostaglandin E2 and prostaglandin F2 alpha were measured by radioimmunoassay in aliquots of foremilk and hindmilk obtained at different stages of lactation (colostrum, transitional, and mature milk) from six healthy nursing mothers who delivered at term. Immunoreactive prostaglandin E2 and prostaglandin F2 alpha were detected in all fresh human milk samples, but not in cows' milk-based formulas. Further studies are necessary to investigate the role of these hormones in the physiologic function, the extrauterine adaptation, and the cytoprotective effect on the gastrointestinal tract in the breast-fed human infant.