Effect of bradykinin on the cytosolic free calcium activity and phosphoinositol turnover in human glomerular epithelial cells

Ren Physiol Biochem. Nov-Dec 1992;15(6):277-88. doi: 10.1159/000173464.

Abstract

The effect of bradykinin (BK) on the intracellular free calcium activity [Ca2+]i and phosphoinositide (PI) turnover was investigated in human glomerular epithelial cells (GEC) in culture. Human GEC exhibited a baseline [Ca2+]i of 114 +/- 3 nmol (n = 81). BK (ED50 10(-9) mol/l) caused a rapid and transient increase in [Ca2+]i, which could also be observed in the absence of extracellular calcium. The effect of BK (10(-8) mol/l) on the [Ca2+]i was inhibited by the BK2 antagonist Hoe 140 (IC50 10(-8) mol/l). BK also induced PI turnover in a time- and dose-dependent manner. A transient increase in (1,4,5)-inositol-triphosphate (InsP3) formation from 1,445 +/- 119 to 4,629 +/- 323 cpm occurred after 5 s. Stimulation of protein kinase C (PKC) by short-term preincubation (15 min) of human GEC with phorbol-12-myristate-13-acetate (PMA) induced a dose-dependent inhibition of the BK-stimulated (10(-7) mol/l) inositol-phosphate formation. Downregulation of PKC by preincubation of human GEC with PMA (24 h, 10(-6) mol/l) or inhibition of PKC by pretreatment with staurosporin (1 h, 10(-6) mol/l) resulted in a slight but significant augmentation of the BK-induced InsP3 stimulation. The data indicate that BK induces stimulation of [Ca2+]i and PI turnover via a BK2 receptor in human GEC. PKC might exert a negative feedback function for the BK-induced PI turnover.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bradykinin / analogs & derivatives
  • Bradykinin / antagonists & inhibitors
  • Bradykinin / pharmacology*
  • Calcium / metabolism*
  • Cells, Cultured
  • Cytosol / drug effects
  • Cytosol / metabolism*
  • Epithelial Cells
  • Epithelium / drug effects
  • Epithelium / metabolism
  • Feedback
  • Humans
  • Kidney Glomerulus / cytology
  • Kidney Glomerulus / drug effects*
  • Kidney Glomerulus / metabolism
  • Phosphatidylinositols / metabolism*
  • Protein Kinase C / metabolism
  • Signal Transduction

Substances

  • Phosphatidylinositols
  • icatibant
  • Protein Kinase C
  • Bradykinin
  • Calcium