Investigation into the effect of systemic single high-dose erythropoietin on the healing of Achilles tendons in rats.

Abstract

This study aimed to examine systemic erythropoietin's effect on the Achilles tendon's healing in a rat model. Twenty-five adult Wistar rats were randomly assigned to one of two groups. The Achilles tendon of each rat was transected 5 mm proximal to its insertion to the calcaneus. All Achilles tendons were then repaired using modified Kessler methods. A single dose (5000 U/kg) of intraperitoneal erythropoietin (EPO) was administered to group I. Group II was a control group and did not receive an EPO injection. Four rats from each group were sacrificed at 1, 3 and 6 weeks after injection. Histopathological assessments were performed by observers blinded to the treatment. Groups I and II showed a similar increase in fibroblast cytoplasmic content and fibrillar collagen in the extracellular matrix. Collagen deposition, cellular proliferation, number of lipid vacuoles and capillary increases were similar between the groups. Evidence from this study has shown no direct effect of a single systemic high dose of EPO on the histological properties of the Achilles tendon in rats.