Why is erythropoietin present in human milk?
Department of Pediatrics, University of Florida, College of Medicine, Gainesville 32610-0296, USA. Erythropoietin receptors (Epo-R) are expressed on cells in the small bowel of human fetuses, but their function has not been defined. We hypothesized that intestinal Epo-R are present postnatally, and that recombinant erythropoietin (rEpo) would increase enterocyte migration and decrease cytokine-induced apoptosis. We used reverse transcriptase-polymerase chain reaction and immunohistochemistry to evaluate the presence of Epo-R mRNA and protein in rat intestinal epithelial cells (IEC-6), and in postnatal human and rat bowel. The effect of rEpo on rates of cell migration and proliferation were established in IEC-6 cells by using cell counting and incorporation of bromodeoxyuridine. To determine whether rEpo affects response to injury, cells were pretreated with rEpo, then were damaged with 25 or 50 ng/mL tumor necrosis factor-alpha plus 2.5 microg/mL cycloheximide. Cell death was determine
