[Relation between erythropoietin production and plasma renin activity in patients with essential hypertension]

Regulation of renal erythropoietin (EPO) production has not yet been clearly established in physiologic as well as in pathologic conditions. Recent studies suggest a possible role for renin-angiotensin system in control of EPO production. An elevation in blood pressure occurs commonly in patients with various forms of anaemia treated with recombinant human EPO. Furthermore it has been found that EPO can alter secretion of hormones engaged in regulation of intravascular fluid volume and vascular resistance. The aim of this study was to determine whether patients with essential hypertension (EH) and healthy subjects differ in EPO secretion and whether EPO serum level is related to renin response to dietary sodium restriction and upright position of the body. 63 patients with EH and 12 healthy subjects were investigated. Patients with EH were divided into subgroups on the following criteria: renin response to dietary sodium restriction and upright position of the body. 63 patients with EH and 12 healthy subjects were investigated. Patients with EH were divided into subgroups on the following criteria: renin response to dietary sodium restriction and upright position of the body and severity of existing hypertension. In all subjects haematocrit value, haemoglobin concentration, erythrocyte count, sodium, potassium, creatinine, iron, ferritin serum levels, total iron binding capacity, plasma renin activity (PRA), erythropoietin serum level and mean arterial blood pressure (MAP) were measured in basic conditions (normal sodium diet). Additionally PRA, EPO and MAP were measured after dietary sodium restriction for three days and upright position of the body for three hours.(ABSTRACT TRUNCATED AT 250 WORDS)