Erythropoietin induces Ca2+ mobilization and contraction in rat mesangial and aortic smooth muscle cultures
Morakkabati, N.; Gollnick, F.; Meyer, R.; Fandrey, J.; Jelkmann, W.
Experimental Hematology 24(2): 392-397
1996
ISSN/ISBN: 0301-472X PMID: 8641371 Document Number: 458086
Reportedly, recombinant human erythropoietin (rhEpo) can induce constriction of isolated resistance vessels. We have studied whether rhEpo affects cytosolic calcium concentration, (Ca-2+)-i, and contraction of cultured smooth-muscle cells grown from rat renal corpuscles and aortae. rhEpo at high dose ( ltoreq 20 U/mL) induced a transient increase in (Ca-2+)-i as detected by fura-2 fluorescence analysis. The number of cells responding with an increase in (Ca-2+)-i was dose-dependent. No significant changes of (Ca-2+)-i occurred when lower doses of rhEpo ( lt 20 U/mL) were applied. The effect of Epo on contraction was studied by phase-contrast microscopy. The number of cells responding with contraction was dose-dependent, too (76% mesangial cells contracting at 200 U rhEpo per mL). The receptor mechanism of this unusual action of Epo still needs to be clarified.