Single-dose erythropoietin does not reduce apoptosis in extracorporeal preserved inguinal fat flaps of the rat

Abstract

Adipose tissue apoptosis is of interest in many fields of medicine. Volume loss due to apoptosis for example remains a major sequela of lipofilling procedures. The aim of the study was to reduce apoptosis of fat cells by administering erythropoietin (EPO), known as an anti-apoptotic acting hormone in vitro, to ex vivo preserved fat flaps.A single dose of 1,000 IE EPO was injected into the inguinal adipofascial flap of rats (n=5) directly after explantation via the femoral artery. The flap was preserved in a bioreactor by continuous perfusion with Hannover solution for ten days. Immunohistochemistry for caspase 3 and EPO receptor was performed, at the following time points: 0, 8, 24, 48 and 240 hours.Compared to adipofascial flaps without pretreatment with EPO, flaps which were treated with EPO did not show a significant reduced level of cleaved caspase 3 activity. In both control and EPO treated tissue, a similar constant increase in cleaved caspase 3 activity was observed. Analysis of EPO receptor revealed that there was no immunoreactivity of EPO receptor in the inguinal fat flaps of the rat.In contrast to in vivo studies we could not demonstrate a beneficial effect of single dose EPO on cell survival in fat flap ex vivo in rats. This is probably due to the lack of the EPO receptor on adipose cells.