EFFECTS OF ERYTHROPOIETIN ADMINISTRATION ON BLOOD-PRESSURE AND URINARY ALBUMIN EXCRETION IN RATS

The effects of recombinant human erythropoietin (rHuEPO) administratio n on blood pressure and urinary albumin excretion were studied in norm otensive Wistar-Kyoto rats (WKY), in spontaneously hypertensive rats ( SHR), and in SHR rats treated with an angiotensin converting enzyme in hibitor (SHR-ACEi). Rats were housed in metabolic cages and treated wi th rHuEPO (150 U/kg body weight [bw] three times a week) for 6 weeks. Control animals received the vehicle only (0.25 mt of physiological sa line). An angiotensin converting enzyme inhibitor was administered in the drinking water for 6 weeks (spirapril 5 mg/kg bw). Systolic blood pressure (SEP), and 24 h urinary albumin excretion (UAE) were measured once a week. No significant differences in SEP were observed between rHuEPO and vehicle-treated normotensive animals at the end of the trea tment (171.9 +/- 4.9 v 172.1 +/- 5.6 mm Hg, respectively). After 6 wee ks, SEP was significantly higher in SHR and SHR-ACEi groups treated wi th rHuEPO than in control groups (239.8 +/- 7.3 and 243.0 +/- 7.3 mm H g v 218.1 +/- 6.0 and 187.9 +/- 4.6 mm Hg, respectively); UAE was sign ificantly higher in groups treated with rHuEPO than in control groups (WKY: 265.9 +/- 19.5 v 127.0 +/- 12.3 mu g/100 g bw, SHR: 1668.4 +/- 5 64.6 v 234.8 +/- 22.9 mu g/100 g bw, and SHR-ACEI: 1522.7 +/- 448.3 v 143.0 +/- 18.9 mu g/100 g bw, respectively). We concluded that erythro poietin treatment causes an increase in arterial pressure in SHR only, and an increase in UAE in both normotensive and hypertensive rats. Th e albuminuric effect was not entirely dependent on increased blood pre ssure. The treatment with an angiotensin converting enzyme inhibitor d id not modify either the proteinuric or the presser effects. (C) 1997 American Journal of Hypertension, Ltd.