BACKGROUND Erythropoietin (EPO) deficiency or inadequate EPO secretion in response to bleeding may result in profound or prolonged anaemia after cardiac surgery. AIM The aim of the study was to evaluate the changes in EPO secretion in patients undergoing off-pump coronary artery bypass grafting (OPCAB). METHODS Blood samples from 43 patients (mean age 65.1 ± 7.6 years) were obtained before ...

Despite its well-known role in red blood cell production, it is now accepted that erythropoietin (Epo) has other physiological functions. Epo and its receptors are expressed in many tissues, such as the brain and heart. The presence of Epo/Epo receptors in these organs suggests other roles than those usually assigned to this protein. Thus, the aim of this review is to describe the effects of Ep...

The regulation of erythropoietin (Epo) production was investigated by competitive polymerase chain reaction, a highly sensitive and accurate means of measuring Epo mRNA levels. Co-amplification of the test sample with added mutant Epo cDNA template corrects for variability in the efficiency of amplification. Epo mRNA levels were determined in tissues of normal rats and in animals with varying d...

The erythropoietin receptor (EPO-R) can be activated to signal cell growth by binding either EPO or gp55, the Friend spleen focus-forming virus (SFFV) glycoprotein. EPO binding induces tyrosine kinase activity and rapid tyrosine phosphorylation of several cellular substrates. To test for gp55-induced tyrosine kinase activity, we performed immunoblots on two murine cell lines that stably express...

Erythroid progenitor cells isolated from patients with polycythemia vera (PV) proliferate and differentiate in methylcellulose in the absence of exogenous erythropoietin (EPO). To investigate the potential role of the erythropoietin receptor (EPO-R) in the pathogenesis of PV, we cultured bone marrow-derived or peripheral blood-derived erythroid progenitors in the presence of neutralizing monocl...

The presence and potential physiological role of the erythropoietin receptor (Epo-R) were examined in human skeletal muscle. In this study we demonstrate that Epo-R is present in the endothelium, smooth muscle cells, and in fractions of the sarcolemma of skeletal muscle fibers. To study the potential effects of Epo in human skeletal muscle, two separate studies were conducted: one to study the ...

In its classic hormonal role, erythropoietin (EPO) is produced by the kidney and regulates the number of erythrocytes within the circulation to provide adequate tissue oxygenation. EPO also mediates other effects directed towards optimizing oxygen delivery to tissues, e.g. modulating regional blood flow and reducing blood loss by promoting thrombosis within damaged vessels. Over the past 15 yea...

Excessive erythrocytosis (EE) is the hallmark of chronic mountain sickness (CMS), a prevalent syndrome in high-altitude Andean populations. Although hypoxemia represents its underlying stimulus, why some individuals develop EE despite having altitude-normal blood erythropoietin (Epo) concentration is still unclear. A soluble form of the Epo receptor (sEpoR) has been identified in human blood an...

Unexpected clonal variability was observed in the content of beta-globin mRNA in erythropoietin receptor (EpoR)-transfected Ba/F3 cells before and after exposure to erythropoietin (Epo). Of 11 clones selected by virtue of G418 resistance and positive EpoR expression, 5 clones showed high levels of beta(major)-globin mRNA before Epo exposure, with subsequent Epo treatment causing little or no in...

Anemia is a common clinical problem, and there is much interest in its role in promoting left ventricular hypertrophy through increasing cardiac workload. Normally, red blood cell production is adjusted through the regulation of erythropoietin (Epo) production by the kidney. One important cause of anemia is relative deficiency of Epo, which occurs in most types of renal disease. Clinically, thi...