Prolonged Duration of Erythropoiesis-Stimulating Agents' Action Delays Disease Progression in Anti-Thy 1 Antibody-Induced Chronic Glomerulonephritis Rats.

ABSTRACT

BACKGROUND: Although erythropoiesis-stimulating agents (ESAs) exert renoprotective effects in renal disease models, it has not been revealed whether the prolonged duration of action of ESAs contributes to their renoprotective effects. OBJECTIVE: We examined whether the prolonged duration of ESAs' action contributes to their renoprotective effects by comparing a divided administration of a short-acting ESA, epoetin beta (EPO), or a single administration of a long-acting ESA, epoetin beta pegol (continuous erythropoietin receptor activator; C.E.R.A.), to a single administration of EPO in chronic glomerulonephritis (GN) rats. MATERIALS AND METHODS: Chronic GN was induced by intravenous injection of anti-Thy 1.1 antibody (0.6 mg/kg) into uninephrectomized rats (day 0). Chronic GN rats were intravenously injected once with vehicle (disease control; DC), EPO 5,000 IU/kg (single EPO), or C.E.R.A. 25 µg/kg (single C.E.R.A.) on day 1; or 3 times during the first week with EPO 1,667 IU/kg from day 1 (divided EPO; total 5,000 IU/kg). Hemoglobin (Hb) level and urinary total protein (U-TP) level which are the indexes of hematopoiesis and renoprotective effects, respectively, were measured several times over 8 weeks. RESULTS: Divided EPO and single C.E.R.A. increased Hb levels more greatly than did single EPO. In all chronic GN rats, elevated U-TP levels decreased transiently 2 weeks after chronic GN induction and then flared again. Single EPO significantly suppressed this exacerbation of U-TP levels compared to DC. Divided EPO and single C.E.R.A. each significantly suppressed the exacerbation of U-TP levels compared to single EPO. CONCLUSION: Prolonged duration of ESAs' action contributed significantly to their renoprotective effects.