Erythropoietin induces Ca2+ mobilization and contraction in rat mesangial and aortic smooth muscle cultures

Exp Hematol. 1996 Feb;24(2):392-7.

Abstract

Reportedly, recombinant human erythropoietin (rhEpo) can induce constriction of isolated resistance vessels. We have studied whether rhEpo affects cytosolic calcium concentration, [Ca2+]i, and contraction of cultured smooth-muscle cells grown from rat renal corpuscles and aortae. rhEpo at high dose (> or = 20 U/mL) induced a transient increase in [Ca2+]i as detected by fura-2 fluorescence analysis. The number of cells responding with an increase in [Ca2+]i was dose-dependent. No significant changes of [Ca2+]i occurred when lower doses of rhEpo (< 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.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Aorta, Thoracic / cytology*
  • Base Sequence
  • Biological Transport / drug effects
  • Calcium / metabolism*
  • Cells, Cultured
  • Cytosol / metabolism
  • Dose-Response Relationship, Drug
  • Erythropoietin / pharmacology*
  • Gene Expression
  • Glomerular Mesangium / cytology*
  • Humans
  • Male
  • Molecular Sequence Data
  • Muscle Contraction / drug effects
  • Muscle, Smooth, Vascular / drug effects*
  • Muscle, Smooth, Vascular / physiology
  • Organ Specificity
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Erythropoietin / analysis
  • Receptors, Erythropoietin / genetics
  • Recombinant Proteins / pharmacology
  • Vasoconstriction / drug effects

Substances

  • Receptors, Erythropoietin
  • Recombinant Proteins
  • Erythropoietin
  • Calcium