[Effect of recombinant human erythropoietin on cytosolic free calcium concentration in platelets].
Intracellular free calcium concentration ([Ca2+]i) was examined in the platelets of 15 control subjects (NT), 6 predialysis patients with chronic renal failure (CRF), 17 patients on hemodialysis (HD), 20 patients on continuous ambulatory peritoneal dialysis (CAPD), 10 normotensive persons with genetic hypertension (GHT) and 8 essential hypertensive patients (EHT). Levels of [Ca2+] i in the platelets were measured by the fluorescent calcium indicator Fura-2. Resting [Ca2+] i in CRF and HD patients was higher than the value in NT and that in CAPD patients was similar to NT. rHuEPO significantly increased the level of [Ca2+] i in CRF and HD patients compared to those in NT. Under resting and EPO-stimulated conditions, the levels of [Ca2+] i in GHT and EHT were higher than those in NT. rHuEPO increased the levels of [Ca2+] i in the absence of extracellular calcium in NT, GHT and EHT. In addition, EPO-stimulated calcium influx in GHT and EHT was greater than that in NT. Thus, it appears that the mechanism of rHuEPO-induced hypertension may be mainly due to elevation of [Ca2+] i. EPO may contribute to the development of genetic hypertension.
Ishiguro
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Department of Medicine, Juntendo University School of Medicine, Tokyo, Japan.
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000097:blood*; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000378:metabolism*; D006977:Hypertension, Renal / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000494:pharmacology
D011994:Recombinant Proteins; D004921:Erythropoietin; D002118:Calcium